Study The Effect of Using Treated and Untreated Recycled Aggregates on Concrete Properties

Abstract

The recycling of concrete rubble can contribute in reducing the total environmental impact of the building sector. In this research, recycled coarse aggregate (RCA) obtained from destroyed buildings in Libya were used to produce a new concrete by replacing Natural aggregate (NA) by (RCA) in the concrete. The percentage of the replacement was (30%, 50%, 70%, 100%).

This study was conducted in two phases, the first phase was conducted without making any treatment for recycled coarse aggregate for producing a concrete. The second phase was treated by soaking recycled coarse aggregate in hydrochloric acid after dilution as an attempt to clean and remove the mortar attached to the aggregate surface (RCAT). The results obtained indicate that the workability, compressive strength and tensile strength of concrete decreases as the percentage of (RCA) in the mixture increases. A gradual improvement in results has been observed when using (RCAT). However, the results encourage using up to 50% of the  recycled aggregate (RCA) and up to 70% of the aggregate soaked in hydrochloric acid for producing environmentally friendly concrete (Green concrete) in order to fulfill good concrete specifications