Expansion of siliceous and dolomitic aggregates in lithium hydroxide solution

Autoclave expansion behaviors of siliceous and dolomite-bearing aggregates in LiOH and KOH solutions were studied. The results show that lithium hydroxide can suppress ASR expansion and induce ACR expansion. It is the duplex effect of lithium hydroxide that could be used for exploring the mechanism responsible for the expansion of dolomite-bearing aggregates in alkali environments. It has been shown that the expansion of argillaceous dolomite limestone with typical texture from Kingston, Ontario, Canada, can be attributed to ACR rather than to ASR. However, some other argillaceous dolomite limestones exhibit both ACR and ASR. Meanwhile, XRD detected that solid products of dedolomitization in LiOH solution were brucite, calcium carbonate and lithium carbonate with a consequent solid volume increase.