Performance improvement of asphalt concretes using fiber reinforcement

This study reports on the laboratory performance, field performance and cost analysis of fiber-reinforced asphalt concrete (FR-AC) pavement using AC60/70 and polymer modified asphalt (PMA) as binders. The performance testing included indirect tensile resilient modulus, indirect tensile strength modulus, indirect tensile fatigue life, dynamic creep and wheel-tracker tests. Field trials of AC60/70 and PMA mixtures, were undertaken with and without fibers and the International Roughness Index, texture depth, and rutting of the mixtures were measured over time. The PMA + Fiber mixture exhibited the best performance among the materials tested. The performance of AC60/70 + Fiber mixture were comparable to PMA mixture. The improvement of both fatigue cracking and rutting were similar for AC60/70 + Fiber mixtures while the improvement of fatigue cracking was higher than rutting for the PMA mixtures. Since the performance of FR-AC was similar for both laboratory and plant mixed specimens, the laboratory mix design results can be used to interpret the field performance. The fiber reinforced AC60/70 mixture was found to be the most economical. The outcome of this research can be used as a guide, for establishing the specification of FR-AC pavement in Thailand and other countries using similar mix design.