Effect of Superplasticizer on Workability of Concrete Containing Crumb Rubber

Crumb rubber concrete was produced by using 10% of recycled fine rubber 400 ?m as the sand replacement. Superplasticizer with 0.25%, 0.5%, 0.75% and 1.0% contents were added into crumb rubber concrete without changing the water-cement ratio purposely to study the effects of superplasticizer to the concrete. The specimens were tested on the age of 28th day. Several tests were carried out to study the effect of superplasticizer such as slump test, compression test, split tensile test, flexural test and ultrasonic pulse velocity test. The results show that an increase of superplasticizer will increase the workability of the concrete without changing the water-cement ratio. It was found that the rubberized concrete with content 0.5% superplasticizer produced better compressive strength, split tensile strength, flexural strength ultrasonic pulse velocity. Keywords: Crumb rubber, Superplasticizer, Workability, Concrete strength