Lithium hydroxide inhibiting alkali-silica reaction expansion and its application

The expansion behavior of concrete microbars with zeolitization perlite autoclaved in KOH, LiOH solution was investigated and the morphology and chemical composition of products were analyzed by scanning electron microscopy and energy dispersive spectra. Results indicate that the mechanism for controlling alkali-silica reaction expansion with LiOH is mainly due to the formation of lithium-containing less-expansive product around aggregate and the protection of the reactive aggregate by the lithium-containing product layer from further attack by alkalis. Expansion behavior of concrete with alkali-silica reactive and alkali-carbonate reactive aggregates autoclaved in different alkalis was studied. The results show that the expansion of concrete microbars is the biggest in NaOH solution and is the smallest in LiOH solution when they are autoclaved in the same molar concentration solution. Under the dual effects of LiOH in inhibiting alkali-silica reaction expansion and inducing alkali-carbonate reaction expansion a small amount of dolomite in the fine-grained siliceous Spratt limestone may dedolomitize in alkaline environment and contribute to the expansion, namely both alkali-silica reaction and alkali-carbonate reaction are existed in Spratt limestone, but alkali-silica reaction is the dominant one.