Speaker
Description
Abstract. Mechanical characteristics of asphalt binders and asphalt mixes can be improved by utilizing asphalt modifiers. Crumb Rubber Modification (CRM) of asphalt mixes has been practiced as an environmental friendly approach for improving mechanical characteristics of asphalt mixes. Crumb rubber enhances fatigue life and rutting resistance of asphalt mixes and decrease their moisture susceptibility. Processed crumb rubber is produced using activated mineral stabilizers and hydrated lime. In the current study the effects of PCR and CRM was evaluated on fatigue and rutting resistance of asphalt mixes. For this purpose, CRM containing mixes (at 20% CR level) were prepared. PCR containing mixes at 20, 25, and 30% CR levels (at percentage of bitumen) were prepared. The evaluation method was consisted of testing cylindrical and slab samples at intermediate and high service temperatures. Samples were tested under Semi Circular Bending (SCB) test at 25⁰C and Hamburg Wheel Track (HWT) test at 40 and 50⁰C temperatures. SCB and wheel-tracking tests were carried out on dry and wet conditioned samples. Based on the obtained results, it was concluded that mixes containing both CRM and PCR materials showed significant enhancement, compared with conventional HMA mixes. The findings of fatigue and rutting tests showed that samples containing 25% PCR exhibited the best.
