Use of Lithium to Prevent or Mitigate Alkali-Silica Reaction in Concrete Pavements and Structures:Final Report

摘要

Alkali-silica reaction (ASR) was first identified as a form of concrete deterioration in the late 1930s (Stanton 1940). Approximately 10 years later, it was discovered that lithium compounds can be used control expansion due to ASR. There has recently been increased interest in using lithium technologies to both controls ASR in new concrete and to retard the reaction in existing ASR-affected structures. This fact book provides information on lithium, its origin and properties, and on its applications. The mechanism of alkali-silica reaction is discussed together with methods of testing to identify potentially alkali-silica reactive aggregates. Traditional methods for minimizing the risk of damaging ASR are presented; these include the avoidance of reactive aggregates, controlling the levels of alkali in concrete and using supplementary cementing materials such as fly ash, slag and silica fume. The final two sections of the facts book discuss the use of lithium, first as an admixture for new concrete construction and second as a treatment for existing concrete structures affected by ASR.