Numerical Model of the Alkali-silica Reaction Development with External Source of Alkalis

Experimental research, in which mortars prepared with reactive aggregates have been exposed to different conditions, has been performed. The samples have been stored in water or 1 M NaOH water solution at 80 °C. Based on the observed strains, ASR extent has been calculated. Mathematical model of combined action of hygro-thermal, chemical and mechanical phenomena has been developed to analyze evolution of the ASR reaction. It is based on mechanics of multiphase porous media. Development of the ASR depends on the alkali content. Diffusion of alkalis from the cement paste to the aggregate grains is considered. Both external alkali sources and alkali binding by the formed ASR gel are taken into account. The proposed mathematical model has been validated by comparison with the experimental results.