Performance of engineered cementitious composites incorporating crumb rubber as aggregate

Abstract

Engineered cementitious composites (ECC) are a special type of fiber reinforced cementitious composites that are reinforced with Polyvinyl alcohol fibers. ECC exhibits outstanding deformable and durability properties. However, the limited availability and high cost of silica sand required for the production of ECC have limited its widespread applications. Hence, it is imminent to find materials that can be used as alternatives to partially or totally replace the silica sand in ECC. This paper presents the results from a feasibility study on the use of crumb rubber which is a recycled material as aggregates in ECC mixtures. In this study, crumb rubber was incorporated to replace the silica sand up to 100% and the influence on the performance evaluated. The study showed that the incorporation of crumb rubber causes a reduction in the strength of the ECC, though these ECC qualify to be used in the structural application. Also, the ductility and the durability of ECC incorporating crumb rubber was improved with the incorporation of crumb rubber. The mid-span deflection and tensile strain of ECC incorporating only crumb rubber as aggregate were found to be 96.8% and 110.2%, respectively higher than the ECC made with only silica sand as aggregate. Also, the incorporation of crumb rubber as aggregate into the mixtures resulted in a reduction in the permeability properties of the composites. The porosity, water absorption and chloride penetration of ECC were reduced by 33%, 36% and 12%, respectively when crumb rubber was used as a 100% replacement of silica sand.