Use of waste tyre rubber as aggregate in double layer concrete paving blocks

This study provided the test results on the mechanical properties of double layer concrete paving blocks (DL-CPBs) obtained by replacing portions of the natural aggregate with waste tyre rubber. The mechanical and physical properties discussed in this paper were compressive and flexural strength, and also the density of blocks. Due to the low strength and stiffness of waste tyre rubber particles, the compressive and flexural strength of DL-CPBs containing rubber appeared to be lower than that of conventional concrete paving blocks (CPBs). The reduction was found to be proportional with the waste tyre rubber content. The incorporation of 10% rubber in the CPB produced the highest level of strength compared to 20%, 30%, and 40% rubber. The reduction of strength was due to the lack of proper bonding between waste tyre rubber particles and the cement paste, as well as the reduction of solid load carrying materials. The results indicated that the density of DL-CPBs containing rubber was lower than that of conventional CPBs