Behavioural study of pavement quality concrete containing construction, industrial and agricultural wastes

Abstract

This study proposes the use of industrial and agricultural wastes as mineral admixtures for enhancing the mechanical and durability aspects of concrete containing recycled concrete aggregates derived from concrete waste. The study was carried out by testing specimens prepared from concrete mixes with and without recycled concrete aggregates and three different mineral admixtures viz: fly ash (an industrial waste), rice husk ash and bagasse ash (agricultural wastes) for their compressive strength, flexural strength, split tensile strength, workability, chloride ion concentrations, carbonation, sorptivity and abrasion resistance in order to assess the variations and improvements. It was observed that concrete mix upon incorporating mineral admixtures showed significant improvement in both mechanical and durability properties when compared to concrete mix with recycled concrete aggregates alone.Fly ash admixed mixes showed a gain of 15% and 24% for compressive and flexural strength parameters, while the gain for rice husk ash mix and bagasse ash mixes was observed to be 12% and 25%, 13% and 20% respectively when compared to recycled aggregate concrete mix without mineral admixtures. Improvements in durability aspects were observed by incorporating mineral admixtures supported by lower parameters for water absorption, sorptivity coefficients and chloride ion concentrations and increased hydration products as concluded from scanning electron microscopic investigations.