Recycling of landfill waste tyre in construction materials: Durability of concrete made with chipped rubber

The goal of current research is to study the effect of waste tyre as a replacement for coarse aggregate at high levels in concrete for non-structural applications to address one of the serious environmental concerns. To reach this aim, waste rubber in a size range of 10–15 mm which needs less energy and cost for grinding compared to fine rubber was used. The total volume of coarse aggregate was substituted by rubber at the rates of 25%, 50%, 60%, 70% and 80%. Mechanical properties were studied through compressive and flexural strength and hardened density tests. Moreover, durability was comprehensively investigated via water absorption, drying shrinkage, electrical resistivity, chloride migration, carbonation resistance and resistance against acid attack tests. Sound absorption performance of different mixes at low and high frequencies were also compared to monitor the impact of rubber content. The results indicated that by the addition of rubber mechanical properties reduced, nevertheless, durability improved. Using rubber enhances the concrete ductility and reduces the density making it appropriate for lightweight concrete. The chloride migration coefficient was reduced up to 80% and electrical resistivity increased up to 87%, by using 80% rubber. Besides, rubberised concrete developed in this research demonstrated superior functional advantages over plain concrete in terms of acoustic performance and sustainability. Despite having lower strength by using rubber in concrete, rubberised concrete made with high content of cost-effective coarse rubber particle is appropriate for non-structural usages particularly in regions where either possibility of aggressive environment is a concern or noise attenuation is critical.