Role of Concrete Incorporating High Volumes of Fly Ash in Controlling Expansion due to Alkali-Aggregate Reaction

Abstract

The results are presented of an investigation dealing with the role of concrete incorporating high volumes of fly ash in reducing the expansion of concrete due to alkali-aggregate reaction. The concretes investigated were made using portland cement and high volumes of low-calcium fly ash. The w/c plus f and the fly ash were 0.31 and 0.58, respectively. One of the high volume fly ash concretes incorporated additional alkalies at a dosage of 3.25 km cubed. Control concrete specimens containing ASTM Type I cement with and without additional alkalies were also investigated. The expansion of concretes was monitored under normal and various accelerated methods. The test results up to 275 days of storage indicate that, at high replacement levels, the fly ash was highly effective in inhibiting the alkali-silica reaction. The expansion of test specimens under both normal and accelerated tests were within acceptable limits.