The effects of surface treatment methods on properties of recycled concrete aggregates

Abstract In developing countries like India, a large quantity of construction and demolition waste is generated every year. Hence the disposal of this waste in large quantity has become a serious problem as it requires huge space for dumping. Considering the state of our country's infrastructure, it will be required to discover new sources of aggregate for the manufacture of concrete in the future due to rising demand and a relatively limited quantity of natural aggregate. One good solution is to obtain Recycled concrete aggregate (RCA) from the material that have been previously used in construction. Natural aggregates have different characteristics than RCA. The existence of mortars in RCA is one of the primary reasons for RCA's lower quality when compared to natural aggregates. In this paper various treatments like water washing, heating and acid soaking are used for removal of attached mortar and enhance the properties of RCA. Following the RCA treatment, mix designs for M35 and M40 concrete grades were created, and the characteristics of the concrete were evaluated and compared to natural aggregate concrete. Concrete mixes are prepared using recycled aggregate, recycled aggregate treated with HCL, recycled aggregate obtained after heating treatment and natural aggregate. These aggregates physical and mechanical characteristics, as well as their strength and performance are determined. However, results show that there is improvement in properties such as workability, split tensile strength and compressive strength when treated aggregates were used.