Influence of lithium hydroxide on alkali–silica reaction

Several papers show that the use of lithium limits the development of alkali–silica reaction (ASR) in concrete. The aim of this study is to improve the understanding of lithium's role on the alteration mechanism of ASR.The approach used is a chemical method which allowed a quantitative measurement of the specific degree of reaction of ASR. The chemical concrete sub-system used, called model reactor, is composed of the main ASR reagents: reactive aggregate, portlandite and alkaline solution. Different reaction degrees are measured and compared for different alkaline solutions: NaOH, KOH and LiOH.Alteration by ASR is observed with the same reaction degrees in the presence of NaOH and KOH, accompanied by the consumption of hydroxyl concentration. On the other hand with LiOH, ASR is very limited. Reaction degree values evolve little and the hydroxyl concentration remains about stable.These observations demonstrate that lithium ions have an inhibitor role on ASR.