INVESTIGATIONS ON RECYCLED CONCRETE AGGREGATE AND MSAND AS AGGREGATE REPLACEMENT IN CONCRETE

Gigantic numbers of building and destruction trashes are produced in emerging countries like India. The clearance of these trashes is serious problem because it requires huge space. The present work is to study the properties of concrete with replacement of 50 % of nature sand by manufactured sand and coarse aggregates by different proportions with recycled concrete aggregates (RCA). A mix proportion for M20 grade concrete is derived with standards confirming to IS codes. RCA was partially replaced for coarse aggregate in the proportions of 10%,20%,30 % and 40%and fine aggregate by M-sand for 50 % as constant. Results showed that recycled aggregates decreases the workability of concrete. But that can be easily avoided with plasticizers. The fresh and hardened properties of new concrete are studied and compared with concrete made using conventional materials. The compressive strength of recycled coarse aggregate (RCA) is found to be higher than that of normal concrete when used up to a 50 %. With respect to the flexural strength, recycled aggregate concrete was slightly lower with increase in % of RCA after 28days. At the end it can be said that the RCA up to 50 % can be used for obtaining good quality concrete