Study on Partially Used Recycled Coarse Aggregate Cement Concrete

The use of recycled coarse aggregate (RCA) is replacing the natural coarse aggregate (NCA) in the concrete construction and has become popular to answer many environmental problems caused by the large volumes of construction and demolition waste (CADW). This paper presents the experimental results of mechanical properties of RCA concrete and compared with NCA concrete. Recycled coarse aggregate was obtained from crushed laboratory concrete specimens. Three grades of concrete M 20, M 25 and M 30 were produced with 50% and 75% of RCA. RCA concrete has compressive strength comparable to NCA concrete. RCA concrete has low modulus of elasticity compared to NCA concrete. This is mainly due to the attached mortar on the surface of RCA and highly angular nature of RCA leads to poor quality of coarse aggregate. In rapid chloride permeability test (RCPT), the chloride penetrating rate is “moderate” for the grade of concrete. From the results, it can be concluded that RCA can be recommended as structural concrete.