A New Approach for Producing Sustainable Concrete by Incorporating Treated Waste Rubber

Abstract

Recently, the increasing number of used tires in landfills has become a major issue. The tire waste is burned, which results hazardous gases that further affect the earth's natural ecosystem. The main objective of this research is to investigate the partial replacement feasibility of fine and coarse aggregates with treated crumb rubber on fresh and hardened characteristics of concrete. This is reducing the consumption of natural resources utilized in concrete. Total aggregates were replaced by crumb rubber (CR) in the concrete mixture at ratios of 2.5%, 5%, 7.5%, and 10% by volume. CR particles were treated by two methods, the first method is soaking in water and the second method is treating by placing CR particles in benzene. The findings indicated that the compressive strength decreased by 20%, 31.67%, 43.33%, and 53.33% than that of the reference mix at 28 days of curing in the case of water treatment, while it decreased by 10%, 16.67%, 33.33%, and 40% in the case of benzene treatment at the ratios of CR 2.5%, 5%, 7.5%, and 10%, respectively. The increase in CR content reduced the modulus of rupture of mixes by 11.6%, 20.9%, 34.9%, and 44.18% in the case of treating CR particles with benzene at ratios of CR 2.5%, 5%, 7.5%, and 10%, respectively. The modulus of elasticity decreased with a higher ratio of CR particles making concrete containing CR suitable for use in pavement, playgrounds, and machine bases. The mixture with the replacement of 2.5% CR of total aggregates and treated with benzene was considered the best mixture containing rubber as it had a little reduction in strength of compressive, modulus of rupture, and indirect tensile with comparison to the reference mix. When the ratio of CR particles was increased, the density of the mixtures decreased.