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Home > Materials > Concrete > Concrete durability and repair

Concrete durability and repair


A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete ¿ background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete ¿ detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete ¿ simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete ¿ worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups ¿ many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88 

A review of service life design of concrete structures
A review of published literature on service life design of concrete structures, concentrating on what has been published since 1991. It concludes that the setting of a standard for service life design is a worthwhile goal in spite of various limitations which have been identified, and encourages greater coordination between European bodies working in this field and the development of a strategy to tackle the research that needs to be done to set a Standard. BR316 

Accelerated carbonation testing of concrete
This Paper provides guidance on accelerated carbonation tests and sources of variability, and makes recommendations on test conditions. The data shows that accelerated carbonation can be used successfully to rank concretes in order of carbonation resistance and to estimate carbonation depths under natural indoor conditions. However, particular attention is required by the user to the accelerated test conditions to ensure consistent results.  IP20/00 

Achieving durable repaired concrete structures
A methodology for protecting and repairing concrete structures using a performance-based intervention approach is presented in this major report, which has been prepared by the CONREPNET network of European research and representative bodies sponsored by the European Commission. It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guide to performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Offers a new way forward for achieving durable and long-lasting concrete repairs Readership All those professionally involved in managing, protecting and repairing concrete structures - engineers, concrete repair specialists, material suppliers and owners of structures EP77 

Alkali-silica reaction in concrete
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330 

Alkali-silica reaction in concrete – background to the guidance notes
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/1 

Alkali-silica reaction in concrete – detailed guidance for new construction
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/2 

Alkali-silica reaction in concrete – simplified guidance for new construction using normal reactivity aggregates
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/4 

Alkali-silica reaction in concrete – worked examples
Concrete can deteriorate as a result of an interaction between alkaline pore fluids and reactive minerals in certain types of aggregates. The commonest mechanism is alkali-silica reaction. Part 1 Background to the guidance notes. Part 2 Detailed guidance for new construction. Part 3 Worked examples. Part 4 Simplified guidance for new construction using aggregates of normal reactivity. DG330/3 

An overview of the BRAC guidance in relation to current guidance on high alumina cement concrete
Detailed guidance and recommendations on design-check procedures were published in 1975. This guidance ('the BRAC rules') is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing precast HAC concrete beams. This electronic document makes the BRAC guidance and addenda available in full in their original form. An overview sets the documents in context with current thinking and guidance.  BR429 

Assessing carbonation depth in ageing high alumina cement concrete
This paper describes sampling techniques and methods of carbonation assessment based on petrography (optical microscopy) and pH indicators. Attention is drawn to aspects of these assessment methods in which special care may be needed, such as in assessing concrete which is damp or partially carbonated. This paper is intended for engineers and materials testing professionals. IP11/98 

Assessing the risk of sulfate attack on concrete in the ground
Links the data given in the 15-year report BR 164 on a study of the sulfate resistance of concrete with recommendations in the revised BRE Digest 363 on the use of concrete in sulfate soils and groundwaters. IP15/92 

Avoiding deterioration of cement-based building materials and components
A series of five technical intelligence reports whose purpose is to ensure that those involved at the sharp end of designing, building and maintaining structures are more aware of potential durability problems in cement-based materials. The reports include a number of case studies concerned with the deterioration of cement-based materials. Each report is available separately.  BR449 

Avoiding the thaumasite form of sulfate attack: two year report
Recent site and lab investigations by BRE on problems of sulfate attack have shown that the mineral thaumasite has been responsible for the deterioration of concretes and mortars specifically designed to give good sulfate resistance. The results of further work presented in this report were used by the Thaumasite Expert Group to establish interim recommendations for concrete mixes designed to minimise deterioration due to the thaumasite form of sulfate attack. BR385 

Behaviour of concrete repair patches under propped and unpropped conditions
A repaired structure has to fulfil the strength and durability criteria so that it can achieve a specified design life with the expected levels of maintenance. However, 'repair of repairs' are sometimes needed as the original repair does not restore a structure to the desired level of performance. Little guidance is available on the redistribution of stresses within a reinforced concrete structure during and after repair. This literature review assesses the available information and the sometime inconsistent views among engineers on whether a structure should be propped during the repairs or left unpropped. FB3 

Carbonation depths in structural-quality concrete
Examines evidence on the performance of concrete in existing buildings and structures in respect of resistence to carbonation and its implications for existing structures, future constructions and research needs. Considers the results of studies of structures in Germany and of concrete cylinders, some stored for over 50 years at BRE. BR75 

Carbonation of concrete and its effect on durability
This Digest discusses the carbonation of normal dense concrete which results from the reaction of atmospheric carbon dioxide gas with hydrated cement compounds. It relates particularly to the assessment of the risk of corrosion to embedded steel. The Digest describes the carbonation process and how the depth of carbonation can be measured. DG405 

Concrete Repair Manual
The most complete collection of information ever assembled on repair, rehabilitation and protection of concrete has been significantly updated to give a single resource for the latest repair solutions. The Concrete Repair Manual combines more than 70 separate publications in over 2000 pages covering every step of the repair process, from evaluation to quality control. This massive two-volume set includes guidance, specifications and research from US and European groups – many of them worldwide leaders in the repair industry. Published jointly by ACI, BRE, Concrete Society, ICRI EP61 

Concrete in aggressive ground
This four-part Special Digest covers the assessment of ground for chemical agents aggressive to concrete, and the specification of concrete to resist chemical attack. It includes provision for combating the thaumasite form of sulfate attack (TSA). A key new concept is the specification of concrete mix according to type of aggregate, since aggregates with high carbonate content are more susceptible to TSA. User-friendly design guides cover specifying concrete for common applications and precast products. SD1 

Concrete repairs
Around 50% of Europe's annual construction budget is spent on refurbishment and repair of existing structures. This report is the culmination of a wide-ranging survey into the performance of both current European concrete repair techniques and inspection practice, and current research projects. It assesses case histories gathered from across the sector from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The survey was conducted by the CONREPNET network, made up of European research and representative bodies sponsored by the European Commission. Features / Benefits Information and analysis on how concrete repairs actually perform in practice Presents evidence of failures and poor performance of some concrete repairs Clearly presented with charts, graphs, tables and highlighted key points Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP79 

Concrete repairs
These two reports derive the European CONREPNET network on concrete repair. The first (Concrete repairs: performance in service and current practice, EP79) assesses case histories gathered from owners of concrete structures, repairers and research institutes, and presents its findings using charts, graphs, tables and photographs. A review of the problems of concrete durability, current issues of sustainability, and the differing expectations of what concrete repairs should acheive, provide an insightful introduction to the subject. The second report (Achieving durable repaired concrete structures: adopting a performance-based intervention strategy, EP77) offers a new way forward for achieving durable and long-lasting concrete repairs. It presents a methodology for protecting and repairing concrete structures using a performance-based intervention approach . It explains current practices and recent research and developments, and the drivers for change. It then considers performance-based approaches, develops concepts for performance-based intervention in concrete repair and sets down ways for translating owners' requirements into technical solutions. The third part deals with issues of applying performance-based intervention. Conclusions from the findings of the network organisations and recommendations on a number of fronts are then made. Annexes provide extensive background information. Features / Benefits Wide-ranging guides to performance of concrete repairs and a new performance-based intervention approach for concrete structures Prepared by expert engineeers and researchers from many parts of Europe Readership Engineers designing and carrying out repair projects, owners and managers of structures, concrete repair contractors, materials suppliers EP81 

Concretes with high ggbs contents for use in hard/firm secant piling
This Information Paper provides guidance on the design of low-strength concrete mixes for use in firm female secant piles. Concretes made using very high levels of ground granulated blastfurnace slag (ggbs) have a successful track record for constructing female secant piles, and provide early-age properties that allow the piling operations to be carried out. However, mixes containing more than 80% ggbs are not covered in BRE Special Digest 1:2005. This Paper builds on laboratory and field data to provide guidance on concrete mixes with 80-95% ggbs for use in the different chemical environments classified in SD1:2005.  IP17/05 

Corrosion of reinforcement in concrete: electrochemical monitoring
This Digest, which is aimed at building owners, lessors and engineers, describes three techniques for assessing reinforcement corrosion using electrochemical methods: resistivity, half-cell potential and corrosion current. Their advantages and disadvantages are discussed together with criteria for the interpretation of collected data. Three examples of the practical application of embedded and retrofitted corrosion probes are briefly described. DG434 

Corrosion of steel in concrete
This Digest sets out the basic principles of corrosion of reinforcement in concrete for all concerned with design, inspection, maintenance, remediation and protection of concrete structures. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance. Part 3 describes the protection and repair of concrete structures subject to corrosion, or which are expected to need such measures to minimise future damage or deterioration.  DG444 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 2 provides concise guidance on investigations of corrision of steel in concrete, the techniques employed and how this can lead to a prognosis for the future performance of existing structures.  DG444/2 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 3 describes protection and repair of concrete structures subject to corrosion damage, or which are expected to need such measures to minimise future damage or deterioration. DG444/3 

Corrosion of steel in concrete
This Digest sets out the principles for design and maintenance of durable concrete structures for owners, tenants, architects, material scientists and contractors, particularly surveyors and engineers involved with design, inspection, assessment, remediation and protection of concrete structures. It examines existing standards of construction and the lessons learned from investigations. Part 1 explains the physical, chemical and electrochemical processes involved in the deterioration of reinforced concrete by corrosion. DG444/1 

Corrosion of steel in concrete: a review of the effect of humidity
The prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement. This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. DG491 

Corrosion of steel in concrete: service life design and prediction
Techniques in the design of new concrete structures, and in the planned maintenance and refurbishment of existing structures, have advanced in recent years. This Digest, complementing Digest 444 Parts 1 to 3, discusses issues relevant to the service life design of new concrete structures and prediction of residual service life of existing structures. It also provides an overview of service life design and whole life costing, and gives references to more detailed guidance and tools for carrying out service life design and prediction. DG455 

Corrosion-protected and corrosion-resistant reinforcement in concrete
A description of the results and potential benefits of using corrosion-protected and corrosion-resistant reinforcement under various conditions, including chloride contamination. IP14/88 

Delayed ettringite formation: in-situ concrete
Ettringite is commonly formed at early ages in concrete cured under ambient conditions; this is not damaging. But in concrete subjected to high temperatures during curing, ettringite formation may be delayed. Its gradual formation in the cooled, set concrete can lead to expansion and cracking by 'delayed ettringite formation' (DEF). It can take up to 20 years for cracking to become apparent. This Paper, which is mainly concerned with in-situ concrete, identifies circumstances in which DEF may cause problems. IP11/01 

Deterioration due to corrosion in reinforced concrete
Discusses ways of assessing the deterioration caused by corrosion in reinforced concrete: methods of repairing the concrete and the implications for future design and construction. IP12/80 

Deterioration of cement-based building materials: lessons learnt
This is an overview of the lessons learnt from BRE technical consultancy case studies involving the deterioration of cement-based building materials and components. The wide ranges of damaging reactions included are: sulfate reactions (thaumasite and delayed ettringite formation), steel-slag expansive reactions (in fill and industrial waste deposits), and acid attack on concrete. Recommendations on how to avoid damage are given. A common characteristic of many of the cases was the build-up of moisture, which was necessary for the damaging reactions to occur. IP4/03 

Durability monitoring of concrete structures
Proceedings of a BRE workshop held on 30 April 1996 at BRE Garston. BR326 

Durability of ageing high alumina cement (HAC) concrete
This report provides a literature review of existing research and summary of BRE work; identifies UK codes relating to HAC concrete; assesses deterioration mechanisms in critical environments; provides information on long-term durability issues; and assesses the implications for structural adequacy.  BR386 

Durability of blastfurnace slag cement concretes
Summarises results of studies of the performance and long-term durability. Gives recommendations for the effective use of blastfurnace slag in concrete. IP6/92 

Durability of pfa concrete
A detailed presentation of the results of a long-term study of the strength and durability of concretes made with pulverised fuel ash and ordinary Portland cement under a range of curing conditions. BR216 

Durability of precast HAC concrete in buildings
This Paper gives guidance on long-term durability issues relating to precast high alumina cement (HAC) concrete components in UK buildings and the implications for structural adequacy. It is aimed at engineers and surveyors concerned with the inspection, assessment and remediation of structures but will also interest building owners.  IP8/00 

Durability of reinforced concrete
This report describes the results of two projects studying the long-term carbonation of reinforced concrete. The first was a joint project between the British Cement Association and BRE to examine the influence of materials and workmanship factors and types of element on carbonation rates under site exposure conditions. The second assesses the effects of practical site curing methods on the long-term carbonation rates of concrete made with different cements. The original printing is now unavailable. When purchased on-line this publication will be supplied printed from a PDF file.  BR360 

Durability studies of pfa concrete structures
Describes the findings of an investigation of structures built within the last 33 years using pulverised-fuel ash (pfa) and ordinary Portland cement concrete. A range of properties was measured on concrete cores taken from these structures. IP11/91 

Effects of alkali-silica reaction on concrete foundations
Alkali-silica reaction (ASR) is known to cause harmful changes in concrete. This paper describes its effects on concrete foundations, and gives examples of the structural problems caused by ASR. IP16/93 

High alumina cement concrete BRAC rules
Extensive research into the structural performance of HAC concrete led, in 1975, to publication of detailed guidance and recommendations on design-check procedures. This guidance ('the BRAC rules') is the best advice available and is still used to assess the structural performance of the many tens of thousands of buildings in the UK containing such precast HAC concrete beams. This report incorporates the original documents, leaving out redundant information, with additional and revised information where relevant. Revised 2002 BR451 

High alumina cement concrete in existing building superstructures
Presents the results and confirms the earlier BRE recommendations with amendments. It includes extensive additional information useful for engineers appraising buildings containing high alumina cement concrete. Describes the work on high alumina cement confirming recommendations made in a 1975 report. BR235 

Internal fracture testing of in-situ concrete: a method of assessing compressive strength
Describes a simple test technique for assessing the compressive strength of concrete in existing construction. Advises on choice of test locations, number of tests required and interpretation of tests. IP22/80 

Minimising the risk of alkali-silica reaction: alternative methods
This Information Paper supplements the guidance in BS 5328: Part 2, Digest 330, and CS TR 30. It provides guidance on alternative methods for minimising the risk of ASR in concrete, including the use of Type II additions (silica fume, fly ash and metakaolin) and one type of admixture (lithium salts). It also recommends that air-entrainment is not adequately affective for minimising the risk of ASR. The recommendations are applicable to concrete mixes with higher alkali content limits than currently specified. IP1/02 

Modelling degradation processes affecting concrete
A number of advances have been made in recent years in the development of techniques that facilitate both the economic design of new concrete structures and planned maintenance and refurbishment. Such techniques are aimed principally at the prevention of premature deterioration, mainly due to the corrosion of the steel reinforcement, and the selection of the most appropriate and cost-effective means of achieving the required service life. Abrasion, and the corrosion of reinforcement induced by carbonation or by chloride ingress, are the most suitable processes for service life modelling. This report considers current approaches to modelling degradation mechanisms that can affect concrete and how these can be used in service life design. Models based on BRE data have been developed for carbonation and chloride ingress and are compared with those given in the literature.  BR434 

Performance-based intervention for durable concrete repairs
This Information Paper introduces the concept of performance-based intervention for durable concrete repairs. It summarises one of the main outputs of CONREPNET, the EC thematic network on the performance-based remediation of reinforced concrete structures. The network facilitated the transfer of information from research to practice, promoted a performance-based approach to remediation of concrete structures and established research and development needs. Features / Benefits Introduces the performance-based approach to repair of concrete structures Developed from 4-year European network of engineers and researchers Outlines the way forward for achieving more durable concrete structures Readership Owners and managers of structures, those responsible for maintaining and repairing structures, and commissioning repair and remediation work.  IP9/07 

Pfa concrete
This set of four reports describes a different aspect of a comprehensive study of the durability of concrete made with pulverised-fuel ash (pfa). The concrete was subjected to various aggressive media for up to ten years. 1 Sulphate resistance, 2 Marine conditions, 3 Acidic groundwaters, 4 Carbonation. AP100 

Progress in European standarisation for the protection and repair of concrete
This paper describes the latest developments in European Standards for the protection and repair of concrete. The standards include materials specifications and test methods for coatings, mortars and other repair materials.  IP11/97 

Reinforced concrete service life design Part 2. Design for durability
Part 2 of this 3-part information paper addresses detailed design with the emphasis on service life related aspects. The detailed design is a key part of the service life design system for reinforced concrete developed by BRE, which can be used to assist designers when embarking on a detailed structural design. This maximises the durability performance of the reinforced concrete structure, using a basic material specification derived from current codes and guidance. Part 1 gives an overview of the service life design system and Part 3 covers service life forecasting and enhancement. IP3/06/2 

Reinforced concrete service life design Part 3. Service life forecasting and enhancement
The BRE service life design system is a systematic approach to assist the designer in meeting the clientÕs requirements for a structure, in terms of service life and functionality. This information paper forms the third part of a 3-part series which together describe the approach to service life design adopted in the BRE system. It details the prediction of actual service life and the provision of measures available to the designer to enhance service life should it be deemed necessary.  IP3/06/3 

Reinforced concrete service life design: Part 1 Overview
This information paper provides an overview of a service life design system developed by BRE for reinforced concrete structures. This system can be used to assist structural designers in meeting client's requirements for service life, functionality and maintenance. It includes best practice guidance for undertaking a client brief, designing for durability and effective execution and maintenance. The guidance in all three parts is combined with the output from specialised models for concrete deterioration to provide a holistic service life design system. Part 2 focuses on optimising the durability design for a structure and Part 3 covers service life forecasting and enhancement.  IP3/06/1 

Results of exposure tests to evaluate repairs to reinforced concrete in marine conditions
Discusses the results of the BRE test (to evaluate repairs to reinforced concrete in marine conditions) applied to seven patch repair formulations. IP18/89 

Review of the effect of fly ash and slag on alkali-aggregate reaction in concrete
Critical review of technical literature published up to May 1994, with bibliography. BR314 

Structural implications of alkali-silica reaction
This report describes research into the structural performance of concrete suffering from alkali-silica reaction (ASR). The first part covers tests on concrete specimens and prestressed beams undergoing ASR on the BRE exposure site. The results indicate that research using accelerated conditioning can be applicable to real structures. The second part covers freeze-thaw tests which show that concrete with ASR may be further affected by the secondary effect of freeze-thaw. BR365 

Sulfide-related degradation of concrete in Southwest England ('the mundic problem')
This substantial report is based on the petrographic study by stereomicroscopy and conventional transmitted and reflected light polarising microscopy of about 30,000 samples of concrete from 2700 domestic and comemerical properties in Cornwall and South Devon. This is supplemented by chemical analysis and density determinations on several hundred specimens, in conjunction with routine screening in accordance with the RICS Guidelines.  BR325 

Sulphate and acid attack on concrete in the ground
It has long been recognised that concrete placed in soil can be damaged by sulfate species in the soil. For over 40 years, BRE has advocated classifying sites according to the concentration of sulfate in the soil or the groundwater. This report takes into account progress in analytical methods and techniques. BR279 

Sulphate resistance of buried concrete
The third report on a long-term (15 years) investigation into the sulfate resistance of a wide range of conretes at Northwick Park and in sulfate solutions. BR164 

Testing anti-carbonation coatings for concrete
Anti-carbonation coatings are surface treatments that have a high resistance to carbon dioxide, and protect concrete from carbonation by acting as a carbon dioxide barrier. As there were insufficient data on the long-term durability of these coatings, natural and artificial weathering programmes were set up at BRE. This paper summarises those data and the findings of the programme. IP7/96 

Thaumasite in cementitous materials
This conference brought together 62 papers from leading international specialists. The papers are grouped into themes: mechanistic/fundamental studies, analytical techniques, laboratory-scale studies of cement replacement materials, limestone filler cements, and general studies, UK and overseas field case studies, geotechnical issues, UK guidance. Papers in PDF format. AP147 

The performance of ageing CAC concrete
This report describes eight case studies of ageing Calcium Aluminate Cement (CAC) concrete structures, ranging from a school building built in the UK in the 1960s containing precast CAC concrete beams, to a cast in-situ marine structure in Canada which is more than 50 years old. BR353 

The thaumasite form of sulfate attack in laboratory-prepared concretes
Describes results of site investigations of problems of sulfate attack, showing that the mineral thaumasite has been responsible for the deterioration of concretes and mortars, even in some specifically designed to provide good sulfate resistance.  BR306 

The thaumasite form of sulfate attack in limestone-filled cement mortars
This report summarises the results of a substantial screening programme set up at BRE to investigate the susceptibility of five series of mortars to the thaumasite form of attack. The report recommends that Portland limestone cements manufactured to BS 7583 should not be used in sulfate conditions above class 1. BR307 

Update on assessment of high alumina cement concrete
A summary, for structural engineers, of the current guidelines for assessing the condition of buildings containing high alumina cement (HAC) concrete and the use of in-situ strength tests for wet HAC concrete. IP8/88