Effect of Aluminum Hydroxide on Control of Alkali-Aggregate Reaction

Abstract

Alkali-aggregate reaction (AAR) is one of serious problems of concrete. It is known that fly ash, blast furnace slag, and so on can control the expansion of concrete by AAR. Natural zeolite is known as material that control AAR expansion, too. This paper shows the effect of aluminum hydroxide on control the expansion of concrete by AAR. It is possible to control the expansion of concrete by AAR when aluminum hydroxide to binder ratio is 4.0%. Especially, when a little of fly ash is combined, the effect of aluminum hydroxide is big. But, when aluminum hydroxide is used with much fly ash, the effect of aluminum hydroxide is not clear. The effect of aluminum hydroxide appears when it dissolves in concrete. In this paper, three different type of aggregate were used in order to clarify the effect of aluminum hydroxide on the expansion of concrete by AAR. The effect of aluminum hydroxide on AAR is somewhat different in the type of aggregate. However, it will clarify that aluminum hydroxide is one of an effective admixture to control the expansion of concrete by AAR. By combining aluminum hydroxide with adequate quantity of fly ash, big effect to control the expansion of concrete by AAR can be expected.