Low Noise and Properties of Double Layer Concrete Paving Blocks

Abstract

Double layer rubberized concrete block (DL-RCPB) was introduced to effectively make use of waste tyre and to improve the performance of concrete pavement block. This study was carried out to justify the effectiveness of using waste tyre rubber as aggregate. In this study, there were eight series of concrete mix with 10 and 20 % waste tyre rubber replacement level and different thickness of facing layer; 10, 20, 30 and 40 mm. The compressive strength was reduced when the percentage of waste tyre rubber was increased. Remarkably, all types of DL-RCPB with rubber percentage up to 20 % achieved minimum required compressive strength of 45 MPa. Moreover, DL-RCPB (20 %) with 40 mm top layer was proven to have the most effective sound absorption concrete mix design with up to 36 % of sound adsorption recorded. Reduction in block density was found when the percentages of rubber were increased. Porosity up to 17 % was recorded for DL-RCPB (20 %). The rough surface of rubber particles tends to attract air on the rubbers’ surface and the trapped air tends to produce voids once the concrete hardened. Porosity of DL-RCPB was increased when the rubber was added to concrete mix, thereby decreasing the density of DL-RCPBs. Low density and high porosity increased the intensity of sound absorption and relatively gives positive impact on the development of low noise CBP as long as the compressive strength was sufficient.