Reuse of Construction Waste for Sustainable Development

Abstract

The use of natural aggregates in the manufacture of concrete, if carried out continuously, can result in a crisis in the availability of natural materials. This should be of concern to all of us because natural resources must be maintained in a sustainable manner. This study aims to utilize construction waste from the demolition of rigid pavement roads on the Trans-Sumatra toll road. One of the main parameters in the design of concrete structures is compressive strength. The compressive strength value in this study is the result of a combination test of a mixture of RCA and natural aggregate (NA) with 3 compositions of RCA coarse aggregate mixture, namely: 30%, 50%, and 70%, and the rest is filled using NA material and 4 compositions of water-cement ratio, namely 0.3; 0.4; 0.5; 0.6. The mix design used is based on SNI 7656: 2012 by modifying the need for coarse aggregate to be replaced with RCA. The test results show that at the age of 7 days, the concrete produces a compressive strength of 25.32 MPa; this achievement is obtained for the RCA composition of 50% and the water-cement ratio is 0.3, while at the age of 14 days, the concrete produces a compressive strength of 25.921 MPa obtained from the mixture. RCA 70% and water cement ratio 0.3. The phenomenon of increased strength at 70% RCA is indicated because the high quality of RCA produces relatively high new concrete, but the bonding process between aggregates is hampered because the cement paste still sticks to the RCA.