Over dependence on natural aggregate used in concrete production poses a serious challenge on environment, and the need to preserve natural resources emerge as growing concern for protecting the environment. Waste tyre accumulation and disposal serves as a potential threat to the environment, for instance, tyre landfills serves as a breeding ground for mosquitoes, pollution to land, water and air. Several researches carried out using chipped rubber in concrete shown a significant reduction in the mechanical strength of the resulting concrete. This research work aimed at using modified waste rubber tyre aggregate in concrete production. Coarse aggregate was replaced with modified waste tyre rubber at 0%, 10%, 20%, and 30% by volume of coarse aggregate. The physical properties of fresh and hardened concrete such as slump, compacting factor and density, compressive, splitting tensile and flexural strength were examined. The slumps result shows a decreased with an increased in chipped rubber contents (36.73%-44.90%). The density decreased with an increased in chipped rubber contents. The resulting decreased are (2.54%-9.68%). The compressive strength of the MCR10 showed a significant increased in strength which resulted in 25.0 N/mm2 (24.54%) when compared to unmodified series at 10% (CR10) and (4.33%) decreased compared to the control mix. An increased in splitting and flexural strength was recorded at MCR10 which were 1.8 N/mm2 and 5.9 N/mm2 (24.05%-27%) respectively. It was concluded that incorporating modified waste tyre aggregate in concrete shows a significant increase in mechanical strengths of rubber chips concrete compared with unmodified rubber chips concrete.
Keywords: Aggregate, Coarse, Concrete, Rubber., Slumps, Tyre
