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About this book

This book presents the work of the RILEM Technical Committee 259-ISR. Addressing two complementary but fundamental issues: the kinetics of the reaction, and how this will affect the integrity of the structure (serviceability and strength), it also provides methodology for assessing past deterioration to enable readers to make engineering/science-based predictions concerning future expansion. The book is divided into six major topics: selection and interpretation of optimal monitoring system for structures undergoing expansion to monitor the progress of the swelling evolution and its consequences; development/refinement of current laboratory procedures to determine the kinetics of the reaction i.e. expansion vs (future) time, and to determine the kinetic characteristics of the time-dependent reaction to be used in a finite element simulation; extrapolation of results from structural component laboratory testing; selection of material properties based on data from existing structures affected by the alkali silica reaction or delayed ettringite formation; identification of critical features that should be present in a finite element code, development of test problems for validation, and a survey of relevant programs able to conduct a transient structural analysis of a structure undergoing chemically induced expansion; and lastly guidelines for finite element codes. The book is intended for practitioners responsible for concrete structures affected by the damaging alkali aggregate reaction, engineers dealing with aging structures, and researchers in the field.

Table of Contents

Frontmatter

Diagnosis

Frontmatter

Chapter 1. Introduction to Diagnosis

Abstract
ASR in concrete typically follows a certain sequence. On the level of the structure, there is an initial period after construction where no expansion occurs. Then the concrete starts to expand and cracks develop, often in a linear way, and can eventually damage the structure (NB slight cracking and signs of AAR are usually insufficient to “damage” the serviceability or safety of a structure).
Andreas Leemann, Tetsuya Katayama

Chapter 2. Assessment of Damage and Expansion

Abstract
An indication about the expansion of the concrete can be derived from the crack-index [1]. The crack-index is determined by measuring the crack width along pre-drawn lines, Fig. 2.1 and is expressed as crack-width per measured length. However, it has to be kept in mind that the formation of the cracks may not be attributable solely to AAR. Still, the crack index indicates a concrete expansion at the studied location in mm/m.
Andreas Leemann, Esperanza Menéndez, Leandro Sanchez

Chapter 3. Field Assessment of ASR-Affected Structures

Abstract
This chapter deals with the structural monitoring of concrete structures which are affected by alkali-silica reactions (ASR). Its purpose is to present an overview of the main proven monitoring and testing techniques that are available to determine the presence of ASR within a structure and assess the remaining capacity. However, the scope is not limited to the possible damage induced by ASR, but it also addresses other outward and inward manifestations of the pathology. The methods presented are illustrated by some case studies, from operational experiences gained in different countries.
Alexis Courtois, Eric R. Giannini, Alexandre Boule, Jean-Marie Hénault, Laurence Jacobs, Benoit Masson, Patrice Rivard, Jerǒme Sausse, Denis Vautrin

Chapter 4. Monitoring of Dams Suffering from ASR at the Bureau of Reclamation

Abstract
Field monitoring of concrete dams affected by alkali-silica reaction is an essential component of the Safety of Dams evaluation process. Visual observations, instrumentation data recorded in the field, and laboratory concrete testing results combined with structural analyses results are key factors in understanding the past behavior of a dam, as well as assessing the structural integrity of a dam given the current conditions.
Jerzy Salamon, William Dressel, Daniel Liechty

Prognosis; Accelerated Expansion Tests

Frontmatter

Chapter 5. Summary of Reported Methods

Abstract
This part of the document discusses a number of techniques used to quantify the in concrete affected by alkali-aggregate reaction (AAR). The principal points of each technique (similarities and differences) are presented and an overall discussion is addressed.
Leandro Sanchez, Christine Merz, Victor Saouma

Chapter 6. Accelerated Expansion Test: Japan

Abstract
This alkali-immersion accelerated test method (80 \(^\circ \)C, 1N NaOH,[1] was originally intended to rapidly identify the swelling potential of concrete core extracted from structure, e.g. [2, Sect. 5.3].
Tetsuya Katayama

Chapter 7. Accelerated Expansion Test: Switzerland

Abstract
This test method covers the laboratory determination of the expansion rate of concrete cores (designated as “residual expansion potential” in the following context) extracted from structures affected by alkali silica reactions.
Andreas Leemann, Christine Merz, Stéphane Cuchet

Chapter 8. Accelerated Expansion Test: France, IFSTTAR

Abstract
Thistest method covers the laboratory determination of the swelling potential and the residual free expansion of concrete extracted from structures affected by alkali silica reactions.
Renaud-Pierre Martin, Bruno Godart, François Toutlemonde

Chapter 9. Accelerated Expansion Test: Canada, Laval University Method

Abstract
This test method covers the laboratory determination of the swelling potential and the residual free expansion of concrete extracted from structures affected by alkali-silica reaction.
Benoît Fournier, Leandro Sanchez

Chapter 10. Accelerated Expansion Test: France, LMDC-EDF

Abstract
The method is an aggregate test where aggregates are extracted from concrete and reused in accelerated mortar tests with added alkali. The mortar tests are used to determine the advancement of the different classes of aggregate sizes used in the structure. Residual expansion is evaluated from inverse analysis of data available on the damaged structure (displacements, cracking measurements).
Alain Sellier, Stéphane Multon, Pierre Nicot, Etienne Grimal

Chapter 11. Accelerated Expansion Test: UK

Abstract
This test method determines the variability of long term dimensional changes in sets of mature concrete cores as they take up moisture by capillary absorption. The dimensional changes are initially due to normal swelling (shrinkage recovery) of concrete from measured increased moisture availability. The moisture then leads to the slow swelling of any pre-existing gel from AAR and, in the longer term, to further AAR reaction with swelling of its gel. The swelling due to AAR is a measure of the “free residual expansion potential” which can arise in the cored concrete at a rate depending on the in-situ moisture and the temperature. The “free” expansion will be modified in the structure by the effects of stress and reinforcement restrain acting in three distinct directions.
Jonathan Wood

Prognosis; Round Robin Expansion Tests

Frontmatter

Chapter 12. Round Robin for ASR Expansion

Abstract
Alkali-silica reactivity (ASR) has been recognized as one of the most deleterious phenomena in concrete. In fact, ASR can cause significant loss of mechanical properties and cracking in concrete structures that could lead to structural failure. The challenge now exists in evaluating the degree of the ASR damage in existing structures so that informed decisions can be made toward mitigating ASR progression and damage. Reliable methods and tools are needed in order to evaluate the condition of ASR affected structures. This evaluation includes (a) tests to determine the degree of expansion that has already occurred; (b) the degree of expansion that can be expected; and (c) the rate at which that expansion can take place.
Ammar Abd-elssamd, Sihem Le Pape, Z. John Ma, Yann le Pape, Samuel Johnson

Chapter 13. Accelerated Expansion Test Sample Report: Japan

Abstract
This report presents results of a round robin test in WG-1 of RILEM TC 259-ISR (ASR prognosis of deterioration and loss of serviceability in structures affected by alkali-silica reaction), performed at the research laboratory of Taiheiyo Consultant (THC) in Japan. This was planned to verify the effectiveness of proposed testing methods in the RILEM WG-1 documents, with the challenges below.
Tetsuya Katayama, Kozo Mukai, Tomomi Sato

Chapter 14. Accelerated Expansion Test Sample Report: Switzerland

Abstract
The Swiss method to determine the residual expansion of concrete from structures is based on the storage of cores in a container at 38 °C and 100 % relative humidity for half a year. First, the cores are conditioned at 20 °C for a week to reach water saturation. Afterwards, they are moved to the container. Length changes are recorded regularly. At the end of the test, the cores are dried at 20 °C and low relative humidity until they reach their initial mass before the start of conditioning. The length change during the storage in the container and the irreversible length change (length difference before conditioning and after drying at the end of the test) are used to assess the expansion kinetics of the concrete.
Andreas Leemann, Christine Merz

Chapter 15. Accelerated Expansion Test Sample Report: IFSTTAR

Abstract
This document provides an example of use of the residual expansion test described in the testing method LPC nr. 44.
Renaud-Pierre Martin, Bruno Godart, François Toutlemonde

Chapter 16. Accelerated Expansion Test Sample Report: DRP

Abstract
This report describes the results of a petrographic investigation aimed at quantifying the degree of damage associated with alkali-silica reaction (ASR).
David Rothstein, Chunyu Qiao

Chapter 17. Accelerated Expansion Test Sample Report: Laval

Abstract
Two test procedures are recommended as per Laval University Method.
Leandro Sanchez, Diego Jesus de Souza

Chapter 18. Accelerated Expansion Test Sample Report: Toulouse

Abstract
This study, realized for EPRI in order to complete round-robin tests, aims at characterizing concrete cores of a concrete and the initial aggregates used for the casting.
Alain Sellier, Stéphane Multon

Chapter 19. Accelerated Expansion Test Sample Report: LNEC/Portugal

Abstract
In this report, the results obtained from the laboratory tests conducted at LNEC, between February 2017 and October 2019, on concrete samples extracted from an existing laboratory-aged slab cast in October 2013, at the Electric Power Research Institute laboratory (EPRI) in Charlotte (North Carolina, USA), with the intent of determining the concrete residual free expansion potential, are presented and analysed.
João Custódio

Chapter 20. Assessment of Round Robin Accelerated Expansion Tests

Abstract
Document reviewed and approved by participants of comparative test.
Andreas Leemann

Prognosis; Benchmark Numerical Studies

Frontmatter

Chapter 21. Benchmark Problems for AAR FEA Code Validation

Abstract
A number of structures worldwide are known to (or will) suffer from chemically induced expansion of the concrete. This includes not only the traditional alkali aggregate reaction (also known as alkali silica reaction) but increasingly delayed ettringite formation (DEF)
Victor Saouma, Alain Sellier, Stéphane Multon, Yann Le Pape

Chapter 22. Benchmark Study Results: EdF/LMDC

Abstract
The model presented here and used for the numerical benchmark has been under development by the LMDC and EDF for fifteen years and is implemented in the finite element code, Code_Aster.
Pierre Morenon, Alain Sellier, Stéphane Multon, Etienne Grimal, Philippe Kolmayer

Chapter 23. Benchmark Study Results: IFSTTAR

Abstract
Within the continuum, the kinematical choice is based on an additive split of the total strain, denoted as usual by the tensor.
Boumediene Nedjar, Claude Rospars, Renaud-Pierre Martin, François Toutlemonde

Chapter 24. Benchmark Study Results: Hydro-Québec

Abstract
The model used by Hydro-Québec Production was developed targeting large hydraulic structures such as dams. It is used by engineers to determine if the hydraulic structures are safe despite the presence of the alkali-aggregate reaction and to predict the long-term behavior as well as its performance for different loading scenarios including seismic loads. The model may use simplifying assumptions to reduce the number of parameters while ensuring that these assumptions are on the conservative side. The code was developed to be embedded inside the finite element software ANSYS using User Programmable Features (UPF). The approach used to implement all the physics required to model AAR in hydraulic structures and to ensure the greatest flexibility while remaining within the framework provided by the commercial software is to program a new element type (commonly named UserElement).
Simon-Nicolas Roth

Chapter 25. Benchmark Study Results: Merlin/ColoradoFinite element benchmarkColorado

Abstract
The AAR model of the author is an uncoupled one, that is the constitutive model is in no way affected by the AAR which itself is considered to be an initial strain (akin of temperature), which grafts itself on the mechanical one. It is implemented in [1], and a complete “validation” of the code with the RILEM benchmark is separately published [2]. This section will describe first the AAR model yielding to the expression of the AAR strain tensor which is accounted for.
Victor Saouma, M. Amin Hariri-Ardebili

Chapter 26. Benchmark Study Results: University of TokyoFinite element benchmarkUniversity of Tokyo

Abstract
A multi-scale chemo-hygral computational system (DuCOM-COM3, [1, 2]) has been developed and used in the simulations. Figure 26.1 shows the summary of this system and it conducts a three-dimensional multi-scale analysis of structural concrete and also can consider recently the multi-ionic equilibrium [3].
Yuya Takahashi

Backmatter

Additional information