Diagnostic Of Concrete Samples Affected By Internal Swelling Reactions

This book offers a complete diagnosis of concrete samples collected from a pile cap block of residential buildings affected by internal swelling reactions. Covering an extensive laboratory campaign to evaluate the transport properties of concrete samples, as well as their physical and chemical composition using advanced techniques to analyse cores extracted from real buildings that have concrete elements affected by internal swelling reactions (ISR). It features several rehabilitation procedures, pile caps repair and rehabilitation design, executed using strengthening procedures to provide the complete restoration of the structural integrity of the element deteriorated. These rehabilitation procedures proved to be a good solution to retrofit pile cap deteriorated by expansions due to internal swelling reactions of concrete. The book also offers a systematic review of the current state of knowledge and it is a valuable resource for scientists, students, and practitioners in various scientific and engineering disciplines, namely, civil and materials engineering, as well as and other interested parties.

This looks at internal swelling reaction mechanisms in concrete such as alkali-aggregate reaction, delayed ettringite formation, and freeze-thaw cycles. It outlines qualitative and quantitative protocols for multi-level assessment, using advanced microscopic and mechanical techniques, and includes a detailed case study.

This book discusses the behaviour of isolated concrete bottle-shaped struts affected by internal expansion reactions (ISR). For that purpose, the numerical modelling of damaged concrete was performed using the Concrete Damaged Plasticity Model (CDPM) implemented in ABAQUS and validated the model through Sankovich's tests. A procedure to automatically obtain the concrete plasticity and damage parameters, essential for CDPM, was developed in Matlab. The inputs were the characteristic compressive strength of the concrete, the equivalent length of the finite element mesh and the ratio between the plastic and inelastic compressive strains. The results showed that the CDPM could represent the load-bearing mechanisms of isolated concrete bottle-shaped struts for a range of several stress levels to which these elements may be subjected in the panels investigated. The numerical simulations for different expansion levels consistently captured the expected damage profile of the panels and the load corresponding to the formation of the first crack, the estimated crack opening, and the ultimate load. For the panels investigated, the reduction observed in the failure load reached values close to 70%, the increase of the tensile plastic deformation was more than 60%, and the maximum crack opening can reach an increase of 113% when compared with those observed experimentally in panels without internal swelling reactions The book also offers a systematic review of the current state of knowledge and it is a valuable resource for scientists, students, practitioners, and lecturers in various scientific and engineering disciplines, namely, civil and materials engineering, as well as and other interested parties.

This book presents a collection of recent research works related to blast resistant design, building pathologies, seismic coating, bottle-shaped concrete struts, delayed ettringite formation and waterproofing. It features eight chapters on building pathologies as well as a detailed set of references and suggestions for further reading. Offering a systematic review of the current state of knowledge, it is a valuable resource for scientists, students, practitioners, and lecturers in various scientific and engineering disciplines, including civil and materials engineering, as well as and other interested parties.

This book describes procedures and methodologies used predominantly to obtain a diagnosis of damaged concrete possibly caused by Alkali-Aggregate Reaction (AAR). It has two primary objectives, namely firstly to identify the presence of AAR reaction, and whether or not the reaction is the primary or contributory cause of damage in the concrete; and secondly, to establish its intensity (severity) in various members of a structure. It includes aspects such as field inspection of the structure, sampling, petrographic examination of core samples, and supplementary tests and analyses on cores, such as mechanical tests and chemical analysis. Evaluation of test data for prognosis, consequences and appraisal will be more fully set out in AAR-6.2.

As critical concrete infrastructure deteriorates, engineers need efficient and reliable techniques to appraise the causes and the extent of deterioration, to evaluate the structural consequences and to select effective management protocols and rehabilitation strategies. This book looks at deterioration caused by internal swelling reaction (ISR) mechanisms in concrete, such as alkali-aggregate reaction, delayed ettringite formation and freeze-thaw cycles. The book provides accessible and comprehensive coverage of recent work and developments on the most common ISR mechanisms leading to induced expansion and deterioration. It addresses the implications of ISR on different scales (micro, meso and macro), outlines qualitative and quantitative techniques to assess the condition of affected concrete and introduces the multi-level assessment protocol, using advanced microscopic and mechanical techniques, particularly the stiffness damage test and damage rating index, as a reliable approach to appraise ISR-affected infrastructure. Also included is a detailed case study of the Robert-Bourassa Charest Overpass in Quebec. Internal Swelling Reactions in Concrete: Mechanisms and Condition Assessment is primarily intended for undergraduate and graduate students, as well as academics interested in the field of concrete durability and condition assessment of concrete. It will also be of interest to engineers and infrastructure owners dealing with ISR-related problems.

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.