Rheological and mechanical analysis of bituminous mixtures modified with recycled crumb rubber by wet technology

Road construction and maintenance is not only expensive, but it also has a huge impact on the environment. Being context sensitive in finding the material for the asphalt pavement with a superior quality have been always a challenge. The use of recycled material might be a good solution for reducing the overall impact of the road infrastructures. This report studied the effect of using crumb rubber in the asphalt mixture. The research was based on a practical experience of using crumb rubber modified mixture in Zola Predosa, Bologna (Italy). The mixtures were also having limestone filler as a modifier. Mastic(Binder-modifier system) and mortar (mastic-fine aggregate system) mixture having different quantities of crumb rubber and limestone filler modifiers have been tested in order to find the best rutting resistance combination with an acceptable stiffness. The rheological tests on bituminous mastics and mortars have done in the laboratories of University of Bologna. The results show that using fine crumb rubber reduces the thermo sensibility of the mastic (Binder Bitumen System) and improves its elasticity. Limestone filler in the other hand increases the mixture stiffness at high Frequencies.