Development of elastic and plastic strains in concrete damaged by alkali-silica reaction during various compression loading tests

In this study, the fracture process of concrete in the presence of alkali silica reaction (ASR) cracks under compressive stress was evaluated. Concrete specimens damaged by ASR expansion at various expansion levels were tested under monotonic, stepwise cyclic, and sustained compressive loadings to evaluate the change in mechanical properties. The evolution of expansion cracks under these loading conditions was assessed using digital image correlation (DIC). In stepwise cyclic and sustained loadings, the elastic and plastic strains generated under different stress levels were separately investigated to elucidate the stress resistance mechanism and the impact of expansion cracks on mechanical properties. An increase in the expansion level was found to remarkably decrease the elastic modulus of concrete but only slightly reduce the compressive strength. Using DIC, expansion cracks were observed with the accumulation of principal strain development even at low stress level. Elastic strains linearly developed in specimens with and without ASR damage, whereas plastic strains increased non-linearly with expansion. Despite the high plastic strains observed before reaching the peak load under stepwise cyclic and sustained loadings, the compressive strength and elastic modulus of concrete remained unchanged regardless of the loading pattern. Based on this evidence, the stress resistance mechanism in the cross-section of ASR-damaged concrete was explained.

Automated summary

This study evaluated the fracture process of concrete with alkali silica reaction (ASR) cracks under compressive stress. The evolution of expansion cracks under different loading conditions was assessed using digital image correlation (DIC). The results showed that an increase in the expansion level significantly decreased the elastic modulus of concrete but only slightly reduced the compressive strength. The stress resistance mechanism in the cross-section of ASR-damaged concrete was explained based on the observed behaviors.