Download or read book Mechanisms and Controls of Alkali silica Reaction and Associated Deterioration in Concrete written by and published by . This book was released on 1988 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alkali Aggregate Reaction in Concrete written by Ian Sims and published by CRC Press. This book was released on 2017-08-01 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alkali-Aggregate Reaction in Concrete: A World Review is unique in providing authoritative and up to date expert information on the causes and effects of Alkali-Aggregate Reaction (AAR) in concrete structures worldwide. In 1992 a first edition entitled The Alkali-Silica Reaction in Concrete, edited by Professor Narayan Swamy, was published in a first attempt to cover this concrete problem from a global perspective, but the coverage was incomplete. This completely new edition offers a fully updated and more universal coverage of the world situation concerning AAR and includes a wealth of new evidence and research information that has accumulated in the intervening years. Although there are various textbooks offering readers sections that deal with AAR deterioration and damage to concrete, no other single book brings together the views of recognised international experts in the field, and the wealth of scattered research information that is available. It provides a ‘state of the art’ review and deals authoritatively with the mechanisms of AAR, its diagnosis and how to treat concrete affected by AAR. It is illustrated by numerous actual examples from around the world, and comprises specialist contributions provided by senior engineers and scientists from many parts of the world. The book is divided into two distinct but complementary parts. The first five chapters deal with the most recent findings concerning the mechanisms involved in the reaction, methods concerning its diagnosis, testing and evaluation, together with an appraisal of current methods used in its avoidance and in the remediation of affected concrete structures. The second part is divided into eleven chapters covering each region of the world in turn. These chapters have been written by experts with specialist knowledge of AAR in the countries involved and include an authoritative appraisal of the problem and its solution as it affects concrete structures in the region. Such an authoritative compilation of information on AAR has not been attempted previously on this scale and this work is therefore an essential source for practising and research civil engineers, consultant engineers and materials scientists, as well as aggregate and cement producers, designers and concrete suppliers, especially regarding projects outside their own region.

Download or read book Alkali silica Reaction in Concrete written by Building Research Establishment. Centre for Concrete Construction and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR).

Download or read book The Alkali Silica Reaction in Concrete written by R N Swamy and published by CRC Press. This book was released on 1991-09-01 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the fundamental causes and spectrum effects of ASR. It considers he advances that have been made in our understanding of this problem throughout the world.

Download or read book Alkali silica Reaction in Concrete Background to the guidance notes written by and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR).

Download or read book Alkali Aggregate Reaction in Concrete written by Marc-Andre Berube and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diagnosis and Control of Alkali aggregate Reactions in Concrete written by James A. Farny and published by . This book was released on 1997 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aggregates containing certain constituents can react with alkali hydroxides in concrete. The reactivity is potentially harmful only when it produces significant expansion. This alkali-aggregate reactivity (AAR) has two forms--alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR, sometimes called alkali-carbonate rock reaction, or ACRR). ASR is of more concern than ACR because the occurrence of aggregates containing reactive silica minerals is more common. Alkali-reactive carbonate aggregates have a specific composition that is not very common. Alkali-silica reactivity has been recognized as a potential source of distress in concrete since the later 1930s. Even though potentially reactive aggregates exist throughout North America, ASR distress in structural concrete is not common. There are a number of reasons for this: 1. Most aggregates are chemically stable in hydraulic-cement concrete 2. Aggregates with good service records are abundant in many areas 3. The concrete in service is dry enough to inhibit ASR 4. The use of certain pozzolans or slags controls ASR 5. In many concrete mixtures, the alkali content of the concrete is low enough to control harmful ASR 6. Some forms of ASR do not produce significant deleterious expansion To reduce ASR potential requires understanding the ASR mechanism; properly using tests to identify potentially reactive aggregates; and, if needed, taking steps to minimize the potential for expansion and related cracking. Alkali-carbonate reaction in concrete was not documented until 1957. Although ACR is much less common, this report also briefly reviews the mechanism, visual distress symptoms, identification tests, and control measures.

Download or read book Alkali silica Reaction Mechanisms and Detection written by and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The deterioration caused by alkali-silica reaction (ASR) was first described 70 years ago in the pioneering paper by Stanton and has since been extensively researched. The traditional attempts to mitigate ASR in concrete structures focused on preventing and/or reducing the amount of gel formed by modifying the chemical environment. Limiting the alkali content of concrete, using supplementary cementitious materials, or using chemical admixtures all have been found to be effective and have been extensively used for that purpose. However, the complexity of chemical and mechanical mechanisms of ASR made it difficult to develop reliable quality control test methods and performance prediction models. Therefore, increased understanding of the fundamental mechanisms of ASR may lead to the development of additional (and possibly better) options for ASR control and for reactivity characterization of susceptible aggregates. The main purpose of this research was to investigate the fundamental mechanisms involved in the ASR process and to advance approaches to detect the damage caused by ASR. A more indepth understanding of the mechanisms underlying ASR, combined with the methods to detect ASR damage developed in the course of this study, is expected to help establish more reliable methods of mitigating ASR and increasing the design life of newly constructed concrete structures.

Download or read book Alkali silica Reaction in Concrete written by Building Research Establishment. Centre for Concrete Construction and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR).

Download or read book Alkali silica Reaction in Concrete written by CRC Press and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR). This Digest is in four parts. Part 1 gives the background to the detailed and simplified guidance contained in Parts 2 and 4. Part 2 gives detailed guidance for minimising the risk of damaging ASR in new construction. Part 3 gives worked examples. Part 4 gives simplified guidance for new construction using aggregates of normal reactivity.

Download or read book Analysis of the Mechanisms of Concrete Deterioration written by Monica Prezzi and published by . This book was released on 1995 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alkali silica Reaction Mechanisms and Detection written by and published by . This book was released on 2014 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alkali silica Reaction in Concrete Detailed guidance for new construction written by and published by . This book was released on 2004 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR).

Download or read book Alkali silica Reaction in Concrete written by Building Research Establishment. Centre for Concrete Construction and published by . This book was released on 1999 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete can deteriorate as a result of an interaction between alkaline pore fluids (prinicipally originating from the Portland cements) and reactive minerals in certain types of aggregates. The mechanism of deterioration is known as alkali-aggregate reaction (AAR); it can occur in a number of forms, the most common being alkali-silica reaction (ASR).

Download or read book Alkali silica Reactivity written by R. A. Helmuth and published by Strategic Highway Research Program (Shrp). This book was released on 1993 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I of this report is a synthesis of knowledge of mechanisms of damage to concrete by alkali-silica reactivity. The details of the alkali silica reaction are discussed, and it is noted that the process is complicated by the effects of drying and growth of shrinkage cracks in exposed surfaces. The presence of chloride salts accelerates alkali-silica reactions. Formation of Friedel's salt and other complex chloride containing salts complicates test results. Part II of the report identifies 10 specific gaps in knowledege of alkali-silica reactions in concrete that limit the ability to control these reactions or to predict performance of concrete with reactive aggregates. These involve rapid and reliable test methods; moisture conditions in highway structures; effects of salts, role of sulfate reactions accompanying expansions caused by reactivity; measurement of aggregate reactivities; effect of restraint on kinetics; mechanisms by which pozzolans prevent expansion; test methods and specifications for pozzolans; and inhibition of reactivity by chemical agents.

Download or read book Mechanisms of Chemical Degradation of Cement based Systems written by K.L. Scrivener and published by CRC Press. This book was released on 1997-04-17 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deterioration of cement-based materials is a continuing problem, as it results in the substantial shortening of the lives of conventional concrete structures. The main costs result from poor performance and the need for early repair. With more advanced applications, where very long service lives are essential, such as the storage of nuclear waste, an understanding of the degradation processes in order to predict long term performance is very important. this book forms the proceedings of the latest Symposia at the Materials Research Society Autumn meeting in Boston.

Download or read book New Approaches For Evaluation and Controlling Alkali Silica Reaction Damage In Deteriorated Concrete written by Sameh Hassan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Alkali-Silica Reaction (ASR) is considered one of the most significant critical internal deterioration mechanisms for concrete. ASR produces internal stresses that causes expansion and extended cracks threatening the country's wealth of existing infrastructure. Since ASR recognition in 1940 by Stanton, many studies had been conducted to evaluate the degree of reactivity for different types of gravel. However, limited research has focused on studying the effect of specimens' shape and size, and casting direction on the accuracy of measured ASR expansion and find a correlation between cylindrical and standard prismatic specimens. Moreover, few studies have attempted to evaluate the optimum expansion level for controlling ASR expansion by strengthening ASR-damaged concrete. An experimental work divided into three phases was conducted to evaluate; (1) The effect of these new approaches on ASR expansion using fused silica (FS) as a fast-acting material, (2) The selection of a suitable jacketing materials based on target performance rather than focusing only on the achieved strength investigating concrete mixtures incorporating four types of fibre and fine crumb rubber aggregates (FCRA) with and without silica fume, (3) The effectiveness of six different strengthening materials as CFRP, BFRP, mortar with GG mesh, mortar with BFRP mesh, FRC, and CRC with BFRP to suppress ASR expansion, and evaluate sensitivity of strengthening time and testing time vs. the strengthening types on the concrete mechanical properties. The results exhibited addition of FS caused a drastic increase in the expansion, and plays a crucial role to adversely affect concrete mechanical properties and durability index until age 180 day, then the effectiveness decreased until 548 days. Specimen geometry and size, and casting direction had a significant effect on the rate of expansion. Cylindrical specimens expanded at a higher rate than the prisms until 56 days in the range from 43% to 37%, and from 9% to 15% at 90 days until test termination at 548 days. Specimens cast vertically exhibited an increase in expansion over the others cast horizontally in the range from 2.63% to 8.41%. Specimens Ø100×200mm reveal lower expansion in the range from 5.89% to 9.52% than specimens Ø75×285mm. Concrete mixtures incorporating steel, macro, and micro polypropylene, micro nylon fibres, and FCRA with and without SF were examined. Based on balancing between mechanical properties, durability indices, and electrical resistivity, FRC incorporating micro polypropylene with SF, and CRC contained FCRA with silica were selected as FRC and CRC jacketing. Strengthening type, strengthening time, and testing time after applying strengthening materials showed a significant effect to control ASR expansion and enhanced the damaged concrete properties. For instance, CFRP exhibited a significant reduction in expansion compared to that with control specimens and followed by BFRP, CRC with BFRP, Mortar with GG, Mortar with BFRP, and FRC, respectively. Moreover, strengthening at early ages revealed decreases mechanical properties as a result of high residual expansion. However, testing at early ages showed higher results proved the exposure conditions had an adverse effect on the strengthening materials.