Studies on lithium salts to mitigate ASR-induced expansion in new concrete: a critical review

This paper provides a critical review of the research work conducted so far on the suppressive effects of lithium compounds on expansion due to alkali-silica reaction (ASR) in concrete and on the mechanism or mechanisms by which lithium inhibits the expansion. After a thorough examination of the existing literature regarding lithium salts in controlling ASR expansion, a summary of research findings is provided. It shows that all the lithium salts studied, including LiF, LiCl, LiBr, LiOH, LiOH·H2O, LiNO3, LiNO2, Li2CO3, Li2SO4, Li2HPO4, and Li2SiO3, are effective in suppressing ASR expansion in new concrete, provided they are used at the appropriate dosages. Among these compounds, LiNO3 appears to be the most promising one. Although the mechanism(s) for the suppressive effects of lithium are not well understood, several mechanisms have been proposed. A detailed discussion about these existing mechanisms is provided in the paper. Finally, some recommendations for future studies are identified.