Sulfate Resistance and Alkali-Silica Reaction of Recycled Aggregate Concrete

Abstract

In this research article laboratory investigations of sulfate resistance and alkali-silica reaction of recycled aggregate concrete are presented. A total of eighteen prisms of 25mm x 25mm x 286mm were prepared using a 1:3 (cement: fine aggregates) mix and 0.4 water to binder ratio. The specimens were prepared in three batches using recycled aggregates, conventional aggregates, and sand. An equal number of samples was used to evaluate sulfate resistance and alkali-silica reaction. The change in length of specimens was measured in a standard way from 1- to 28 days. The results at 14- and 28-days show that the percentile change in length of all specimens is less than the specified limit of concerned standards. The length change recorded at 14 days (in accordance with ASTM C1260 recommendations) of recycled aggregates is 342% (for alkali-silica reaction) and 57% (for sulfate resistance) better than conventional aggregates and sand. Therefore, the performance of recycled aggregates is concluded better compared to conventional aggregates and sand for both alkali-silica reactivity and sulfate resistance.