Physically based models to study the alkali-silica reaction

Cyrille Dunant, Karen Scrivener
Ice Publishing, 2016
Article

The Laboratory of Construction Materials in Lausanne has been studying the alkali-silica reaction for more than 10 years, advancing the understanding of the reaction, and also producing microstructural models which can be used to predict quantitatively the degradation of affected concrete. This paper provides an overview of these developments. The authors present experimental evidence of the link between aggregate degradation and expansion, a formulation of the microstructural model and a proposition for a macrostructural model derived from their computations.

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Cyrille Dunant, Karen Scrivener
Ice Publishing, 2016
Article

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https://infoscience.epfl.ch/record/223143?ln=fr

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Micro-mechanical modelling of alkali-silica-reaction-induced degradation using the AMIE framework

Cyrille Dunant, Karen Scrivener

AMIE. a finite element/extended finite element framework, has been designed to provide the tools to run detailed microstructural simulations; this paper demonstrates the possibility of simulating the mechanisms underlying the alkali-silica-reaction (ASR). The numerical model presented provides a better understanding of experimental observations. Macroscopic free expansion and degradation of mechanical properties have been previously linked to the extent of reaction. The connection between microscopic and macroscopic measurements, simulated by the model, supports the hypothesis that damage is induced by growing gel pockets in the aggregates. (C) 2009 Elsevier Ltd. All rights reserved.

2010

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Relation of expansion due to alkali silica reaction to the degree of reaction measured by SEM image analysis

Mohsen Ben Haha, Emmanuel Gallucci, Amor Guidoum, Karen Scrivener

Scanning Electron Microscopy Image Analysis (SEM-IA) was used to quantify the degree of alkali silica reaction in affected microbars, mortar and concrete prisms. It was found that the degree of reaction gave a unique correlation with the macroscopic expansion for three different aggregates, stored at three temperatures and with two levels of alkali. The relationships found for the concretes and the mortars overlap when normalised by the aggregate content. This relationship seems to be linear up to a critical reaction degree which coincides with crack initiation within the reactive aggregates. © 2007 Elsevier Ltd. All rights reserved.

2007

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Influence of visco-elasticity on the stress development induced by alkali-silica reaction

Cyrille Dunant, Alain Benjamin Giorla, Karen Scrivener

The alkali-silica reaction causes long-term degradation in the microstructure of affected concrete as well as macroscopic expansion. In this paper, a micro-mechanical model based upon an explicit representation of the microstructure has been used to simulate the role of creep on the expansion and damage induced by the reaction. The model accounts for the coupling between damage propagation and stress relaxation in the cement paste. This study indicates that the influence of the visco-elastic nature of the material on the overall expansion is within the experimental scatter. However, it is shown that creep can explain the comparatively low amount of damage in the cement paste as observed experimentally. Creep also increases the amount of damage in the aggregates when the rate of reaction increases. Overall, the results presented in this paper indicate that accelerated experiments may not be representative of the degradation in the field at equivalent degrees of reaction. (C) 2014 Elsevier Ltd. All rights reserved.

Pergamon-Elsevier Science Ltd2015

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