THE IMPACT OF RUBBER ADDITIVE CONTENT ON THE PROPERTIES OF CEMENT COMPOSITE

This paper analyses the impact of rubber additive content on the properties of cement composite. It describes the materials and the test methods used to determine various parameters of the composite mix and the cured composite. The properties of the cured composite were tested and compared. The effect of the amount of rubber additive on the following properties of cement composite was tested and analysed: slump flow, density, ultrasonic pulse velocity, compressive and flexural strengths, thermal conductivity, water absorption, and resistance to freeze-thaw cycles. The cement composite was produced by using crushed waste tyre granules as fine aggregate, i.e. sand was replaced with crushed tyre granules from 0 % to 10 %. The tests showed that the rubber additive used as sand replacement had little impact on the properties of the cement composite: density, ultrasonic pulse velocity, flexural and compressive strengths of the modified composite decreased, but resistance to freeze-thaw cycles increased. According to the test results and their analysis, 10 % is the optimal rubber additive content to be used as sand replacement in cement composite, which would have higher frost resistance and a lower coefficient of thermal conductivity