Characterization of modified crumb rubber concrete

Abstract

Concrete is a very important construction material used worldwide for the construction of bridges, buildings, dams, kerbs, patios, pools, roads, walkways and other civil engineering structures. The constituents of concrete are cement, coarse aggregate, fine aggregate and water. Efforts were made in this work to evaluate the suitability of crumb rubber as a partial substitute of sand in concrete mixes. This research evaluated the effects of partial substitution of sand with crumb rubber on the mechanical properties and microstructural formation of modified crumb rubber concrete. The control concrete sample and concrete samples with 1, 2, 3 and 4% sand content in the concrete substituted with crumb rubber were cured for 3, 7, 28, 90 and 120 days, respectively, and then tested. The laboratory experiments conducted on the concrete samples were workability, bulk density, compressive strength, tensile splitting strength, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Improvement in the strength and densification of the microstructure of the concrete samples occurred as the curing age increased from 3 to 7, 28, 90 and 120 days, respectively. This research further showed that marginal improvement in both the strength properties and microstructural formation of the modified crumb rubber concrete can be achieved by substituting 1% sand with crumb rubber.