Effect of Incorporating Shredded and Crumbed Rubber in PavementGrade Concrete on Elasticity and Toughness Moduli

Used car tires are generally recycled at the end of their lifecycles to make useful products. However, the phenomenon of dumping used tires in Kuwait has reached significant levels, with a “tire graveyard” containing over 7 million tires being formed in a remote area of the country. This landfill is a major environmental hazard and poses a major risk to the public health that wouldn’t be allowed in other parts of the world. To mitigate the environmental impact, the tires must be recovered and recycled at a large scale. This study aims to quantify the impact of incorporating repurposed rubber products on the toughness and modulus of elasticity of concrete. The rubber products were incorporated into concrete individually and tested to examine their properties and effects on a benchmark mix before creating a hybrid mix that contains both materials. The concrete was tested for its slump, compressive strength, split tensile strength, modulus of elasticity, toughness, and stress-strain behaviour. The use of shredded and crumbed rubber had a detrimental impact on most concrete properties examined in this study; however, the crumbed rubber improved the toughness of the concrete. Additionally, the hybrid mix displayed similar behaviour to its constituent replacement materials, with the most notable observation being a sharp drop in the mix’s toughness. Overall, the rubberized concrete displays suitable properties (compressive strength, modulus of elasticity, and toughness) for use in paving structures. Further studies could evaluate the long-term effects of using this concrete in a hot weather climate.