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

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.