The usage of recycled materials on hot mix asphalt

Abstract

The demand for fresh aggregates increases as the number of road maintenance and/construction project increases. However, continually mining fresh aggregates will result in irrecoverable environmental damage, and thus, engineers are looking for alternatives aggregates that are more environmentally friendly to be used. The paper discussed the usage of several recycled materials that were mixed with hot mix asphalt (HMA) to be used as surfacing pavement layer, including coconut fibre, Styrofoam, crumb rubber, and recycled asphalt pavement (RAP). A number of tests, which are Marshall, Cantabro Loss, and Indirect Tensile Strength tests were used to evaluate the performance of the asphalt mixtures that were mixed with recycled materials. Both coconut fibre and RAP were mixed as filler or substitute for fresh aggregates, while both Styrofoam and crumb rubber were melted and mixed with the binder. It is found that best amount for coconut fibre, RAP, Styrofoam, and crumb rubber to be added to the HMA are 0.6% of total binder weight, 100% of coarse aggregates, 2.5% of the binder weight, and 3% of total mixture weight, respectively.