ABSTRACT

High modulus asphalt concrete (HMAC) mixtures are produced using hard grade binders or modified bitumen and are known to have exceptional resistance towards rutting and fatigue. Due to the similarity between hard binder and aged reclaimed asphalt (RA) binder, HMAC mixtures have great potential to incorporate higher percentages of RA material. Here we present a study evaluating the performance of HMAC mixtures incorporating high content of RA material. Both hard grade binder and polymer modified bitumen (PMB) were used for all the mixtures with RA content varying from 0% to 70%. The laboratory performance of mixtures was examined using wheel tracking test, semi-circular bend test, thermal stress restrained specimen test, water sensitivity test and four-point bending test. The results demonstrated that it is possible to develop HMAC mixtures with satisfactory performance using RA content up to 70%, by using PMB binder. The mixtures produced using PMB binder outperformed conventional hard grade binder mixtures especially for use in regions with extremely cold winters.

摘要

高模量沥青混凝土 (HMAC) 混合物是使用硬质粘合剂或改性沥青生产的，并且已知具有出色的抗车辙和抗疲劳性。由于硬质粘合剂和老化再生沥青 (RA) 粘合剂之间的相似性，HMAC 混合物具有加入更高百分比的 RA 材料的巨大潜力。在这里，我们提出了一项研究，评估含有高含量 RA 材料的 HMAC 混合物的性能。硬质粘合剂和聚合物改性沥青 (PMB) 均用于所有 RA 含量在 0% 至 70% 之间的混合物。混合物的实验室性能通过车轮跟踪试验、半圆弯曲试验、热应力约束试样试验、水敏感性试验和四点弯曲试验来检验。结果表明，通过使用 PMB 粘合剂，可以使用高达 70% 的 RA 含量开发出性能令人满意的 HMAC 混合物。使用 PMB 粘合剂生产的混合物优于传统的硬质粘合剂混合物，尤其适用于冬季极冷的地区。