ASR induced by chloride- and formate-based deicers in concrete with non-reactive aggregates

Despite ongoing efforts to prevent the damaging effects of alkali-silica reaction (ASR) in concrete structures, this phenomenon still exists and causes significant degradation. This study aims to investigate the role of various deicing agents in provoking ASR by examining volume expansion, cracks, and microstructure of mortar and concrete containing aggregates identified as non-reactive by standard ASR test methods. To achieve this, the concrete specimens undergo simulated operating conditions testing to induce ASR expansion, with an external supply of alkali from chloride- and formate-based deicers. The findings suggest that the configuration and concentration of the deicing agent used, as well as the mineral composition of the aggregate that was previously identified as non-reactive, can significantly impact the expansion and damage caused by ASR. The results indicate that existing methods for testing aggregates for ASR may have limitations when formate-based agents are used.