THE EFFECT OF PARTIAL REPLACEMENT OF AGGREGATES WITH RECYCLED CONCRETE AGGREGATES ON THE COMPRESSIVE STRENGTH OF CONCRETE

ABSTRACT

This study examines the viability of substituting Recycled Coarse Aggregate (RCA) for natural aggregate in structural concrete. In this work, the aggregate impact value of the RCA was obtained and the effects of RCA on the characteristics and durability of fresh and hardened concrete were investigated Discarded used crushed concrete from the laboratory was utilized in the research and processed (crushed) to usable coarse particle size. For the mixes various percentages of RCA was used which was 0%, 5%, 10%, and 20% of the total weight of the natural coarse aggregate. The tests carried out included sieve analysis of particle, aggregate impact value, slump test and then the compressive strength of the different mixes after curing for 7,14, and 28days. The outcomes demonstrated the poor mechanical and physical qualities of the recycled coarse aggregates. When recycled coarse aggregates were used, compressive strength decreased, and aggregate impact value was lower than that of regular granite (coarse Aggregate). The hardened density of concrete was not significantly affected by the RCA, and an increase in recycled aggregate content led to a decrease in capacity. In conclusion it was discovered that the 5% replacement was a bit suitable for concrete construction because it was closer to the desired target strength.