HPC simulations of alkali-silica reaction-induced damage: Influence of alkali-silica gel properties

The alkali-silica reaction (ASR), a common cause of internal concrete degradation, is characterized by the formation of hydrophilic gel pockets inside the aggregates. These gel pockets swell by absorbing water, thus causing expansion and cracking of the concrete. In this work we have used high-performance computing simulations to investigate how the various gel properties, such as the Young's modulus, influence the mechanical degradation process of ASR. It is found that the relationship between the concrete expansion and the loss of elastic modulus is solely affected by the density of gel pockets and does not depend on the material properties of the gel. The ASR model developed in this work, however, overestimates the loss of elastic modulus. This can be explained by the fact that the visco-elasticity of the cement paste and the load-bearing capacity of the ASR-induced cracks are not considered in the model.