An investigation into the techniques for improving the properties of crumb rubber concrete

Motor vehicle tires are discarded every year where the majority ends up in land fill. This poses a serious ecological threat as the tires contain many toxic components and contribute to a loss of biodiversity. From the economic and environmental perspectives, inclusion of recycled rubber in concrete would reduce costs as well as conserve the component materials used in concrete. Past studies have indicated poor-mechanical properties of concrete with the sole inclusion of recycled tire rubber. This paper presents an experimental investigation to improve the workability and hardened properties through sodium hydroxide surface treatment of recycled crumb rubber, and silica fume. Ten concrete mixes were prepared with the volumes of recycled rubber ranging from 10% to 30%. The test results were compared with a control concrete mix. The investigation indicated that favorable strength could be achieved with the addition of 10% treated rubber. Test results and analysis details are presented in the paper.