Understanding long-term ASR expansion in glass powder ternary concrete blends through accelerated solubility test

Abstract

Glass powder (GP) has recently been recognized as a pozzolan by Canadian (CSA) and American standards (ASTM). However, the risk of ASR limits its widespread use in concrete production. This study analyzed a seven-year expansion dataset of GP binary/ternary concrete and correlated it with an accelerated solubility test designed with a synthetic pore solution. Results show that, despite the GP capacity to mitigate ASR, binary blends exceeded the normative expansion threshold. Ternary blends, particularly GP/metakaolin, proved most effective at reducing alkali levels and expansion. Low modified chemical index, reduced Na + K levels, and increased calcium consumption provided lower expansion. The analysis of the dissolution rate and different solution/binder ratios revealed that Na release is controlled by dissolution kinetics, rather than the GP content in the concrete. Early Na release in low GP mixes promotes alkali incorporation into pozzolanic hydrates, while high GP mixes saturate the pore solution, restricting further GP dissolution.