Use of shredded rubber tire aggregates for roller compacted concrete pavement

Recycling of waste rubber tires in pavements is considered as ecological and economical solutions due to their advantages. It may help preserving natural resources and producing an eco-friendly material. Roller compacted concrete used in pavements (RCCP) has the same basic ingredients as in ordinary concrete. But unlike the conventional concrete, it is an enough drier mix-stiff to be compacted by vibratory rollers. This study aims to experimentally investigate the possibility of using shredded rubber tire in RCCP. The rubber particles are added to mixes as a partial replacement by volume of some parts of natural crushed aggregates. Unit weight, mechanical properties, modulus of elasticity and porosity are evaluated and compared according to the rubber content in the concrete mix. The effects of compaction energy and roughness of rubber surfaces are also studied. The results obtained showed that the inclusion of rubber particles in RCCP mixes will change their characteristics in fresh state as well as hardened state. Even though the mechanical properties decrease when rubber content in the mix is increasing, it should be noted that it is possible to use rubber particles in low traffic pavements project. In the other hand, rubber particles may improve some desired technical characteristics such as; porosity, ductility and cracking resistance performance. In addition to that, it may be more environmentally efficient to use rubber aggregates in RCCP, because this helps to remove some parts of these wastes and protect the environment. The performance of RCCP with shredded rubber additions can be improved by modifying the roughness of rubber particle surfaces, when the optimal rubber content depends on technical requirements and the destination of project. (C) 2014 Elsevier Ltd. All rights reserved.