Effect of applied stresses on alkali–silica reaction-induced expansions

The mechanical effects of alkali–silica reaction (ASR) have to be modeled in order to assess the deterioration level and the stability of ASR-damaged concrete structures. Several experimental programs have shown the effects of compressive stresses on ASR-induced strains. The effect is so significant that assessment models have to take into account the modification of ASR expansions due to applied stresses and the consequences on the mechanical response of damaged structures. This paper presents and analyzes measurements performed on concrete specimens subjected to several states of stresses along the three directions (due to applied stresses and to passive restraint). Mechanical calculations show that the volumetric expansion imposed by ASR is constant whatever the stresses conditions. They point out the “expansion transfer” occurring along the directions which are less compressed; thus, the effect of stresses on ASR expansions anisotropy can be precisely quantified.