Recycled Waste Tires Management in Constructions

Abstract

Concrete is one of the most commonly used materials in construction worldwide. Yet the production of concrete from raw materials, such as cementitious materials, water, sand, and natural aggregate, leads to the release of significant amounts of CO2 and greenhouse gases. Therefore, there is a growing interest in producing sustainable concrete using recycled materials. This study will focus on waste management considering the incorporation of recycled tires as a replacement for fine and coarse aggregate in structural concrete. These waste car and truck tires present serious environmental challenges when dumped into landfills as they consume large amounts of space, contaminate the air, soil, and water, and impact human health. The reuse of rubber is therefore inevitable. This study conducts a life cycle cost analysis (LCCA) to compare the cost-effectiveness of a conventional concrete mix (RC1) with a rubberized concrete mix (RC2). Furthermore, to promote the use of eco-friendly materials in concrete mixes, this study suggests the use of seawater as a replacement for freshwater in both the conventional mix and the rubberized concrete mix in order to eliminate the cost and energy consumed during the desalination process. The LCCA results show that the rubberized concrete (RC2), obtained by replacing 5% of aggregate and mixing it with seawater, is more cost-effective than RC1, with a cost savings of 30%.LCCA data were acquired by investigating thirteen concrete mixes (a control mix; 5%, 10%, and 20% rubber aggregate substitutions mixed with freshwater; and 0%, 5%, and 10% rubber aggregate substitutions mixed with seawater). Moreover, the impact of rubber and seawater was evaluated on fresh and hardened concrete characterizations. The results show that as the rubber and seawater contents were increased, the workability, density, and compressive strength were decreased; however, for durability in terms of Rapid Chloride Permeability (RCP) and water absorption, rubberized and seawater concrete mixes outperformed the control mix. Our selection of RC2 for LCCA is based on its good fresh and mechanical characterizations in comparison to the other rubberized concrete mixes. In its approach to its subject, this study is an example of multidisciplinary research, as it synergizes construction management through life cycle cost analysis with construction engineering materials area.