Effect of recycled coarse aggregate and manufactured sand in self compacting concrete

摘要

ABSTRACT The possibility of utilizing Manufactured sand (M-sand) and Recycled Coarse Aggregate (RCA) obtained from Ready Mix Concrete (RMC) plant to make self-compacting concrete is evaluated in this research work. In this experiment, 25 Concrete mixes are made in which the Natural Coarse Aggregate (NCA) is replaced with RCA by an amount of 25, 50, 75 and 100%. Similarly, natural river sand is replaced with M-sand by an amount of 25, 50, 75 and 100%. The cement content, water and silica fume are kept back as constant for all mixes. The effect of M-sand and RCA on the fresh and hardened properties of SCC is evaluated. This investigation results showed that the hardened properties of concrete with 50% of M-sand are significantly increased when compared to the control mix. Results showed that the hardened properties of the SCC with 100% of RCA are lesser than the conventional concrete. Therefore, the strength decreases with an increase in the percentage of substitution of RCA. However, the results showed that the SCC with low and medium compressive strength (20MPa – 45MPa) can be achieved by using M-sand.