On the mechanical behaviour of concrete subjected to alkali-aggregate reaction

A simple continuum theory is presented for the description of mechanical effects of alkali-aggregate reaction in concrete. The formation of alkali-silica gel leads to a progressive expansion of the material. The rate of expansion depends, in general, on the chemical composition of concrete mix, in particular on the available alkali content of the cement matrix. The progress in the reaction is assumed to be coupled with the degradation of mechanical properties, the latter described within the framework of elastoplasticity. The formulation is illustrated by some numerical examples evaluating the influence of the reaction on the mechanical characteristics of the material.