Laboratory Evaluation of Aging on Engineering Properties of Fine-Graded Porous-Asphalt Concrete

摘要

Porous-asphalt concrete (PAC), with its large portion of void content, would result in an increased potential for accelerating aging. Rapid oxidation of the asphalt binder films has an adverse impact on the structural durability of PAC pavements. In addition, the use of fine-graded PAC is more desirable; they have a potential to be more economical because they can be placed in thinner layers. The aim of this work is to characterize the influence of aging on the engineering properties of fine-graded PACs. Test results show that aged PAC mixtures are found to have the better performance in tensile strength and rutting resistance compared to unaged PACs, but the aging has a detrimental influence on the raveling resistance and moisture susceptibility. The 4-day long-term aging procedure led to a considerable reduction in the tensile-strength ratio for PAC mixtures irrespective of binder type and gradation. In addition, the values of resilient modulus and tensile strength for the fine-graded PACs appeared to be higher than those for the coarser-graded PAC mixture. Based on the results obtained from the wheel track testing, the use of premium asphalt enhanced the cohesive strength and adhesion, thereby reducing the proportional rut depth of PAC. In terms of the overall performance evaluation, the fine-graded PAC with the highly modified asphalt binder can be used without compromising engineering properties.