Improvement of Recycled Concrete Aggregate Properties using Alkali-Activated Binder Treatment

Abstract

This article studies on the effects of using paste-treated recycled concrete aggregate (RCA) on the characteristics of concrete. Cement paste, alkali-activated high-calcium fly ash paste, and alkali-activated high-calcium fly ash paste containing dolomite paste were used to treat recycled concrete aggregate. Natural concrete aggregate (NCA) was substituted with RCA at weight percentages of 0%, 25%, 50%, 75%, and 100%. The properties of coating material and concrete were investigated. The experimental results indicated that using treated RCA in replacement of NCA is a viable alternative material for replacing nonrenewable natural resource components in concrete, as well as making it more sustainable and ecologically friendly. As RCA was surface treated with coating materials, the characteristics of the concrete were substantially enhanced when compared to the control mix.