ABSTRACT

This study evaluates the oxidation ageing properties of asphalt blends and mixtures combined with various percentages of RAP and SBS-modified binder, rejuvenator and neat binder. Four ageing methods were conducted in the laboratory on the asphalt blends and mixtures. The results showed that the G-R parameter, the ICO and the flexibility index increased, while the ΔT_cr decreased with the RAP content and the ageing level. The SBS-modified binder and rejuvenator improved the cracking resistance of the RAP binder and mixture. After PAV 20 h ageing, the asphalt blends containing a low amount of RAP were equivalent to their virgin binder after PAV 40 h ageing. The asphalt blends containing a low amount of RAP after PAV 40 h ageing were equivalent to their virgin binder after PAV 60 h ageing. It was found that binders subjected to RTFO, PAV 20 h ageing, PAV 40 h ageing, and PAV 60 h ageing had rheological and chemical properties equivalent to those of loose mixtures subjected to the STOA protocol for 4 h at 135°C, the LTOA protocol for 8 h at 135°C, the LTOA protocol for 12 h at 135°C, and the LTOA protocol for 24 h at 135°C, respectively.

摘要

本研究评估了沥青混合料和混合料与不同百分比的 RAP 和 SBS 改性粘合剂、再生剂和纯粘合剂的氧化老化性能。在实验室中对沥青共混物和混合物进行了四种老化方法。结果表明，GR参数、ICO和柔度指数增加，而ΔT _cr 随着RAP含量和老化程度的降低。SBS 改性粘合剂和再生剂提高了 RAP 粘合剂和混合物的抗裂性。在 PAV 20 小时老化后，含有少量 RAP 的沥青混合物与 PAV 40 小时老化后的原始粘合剂相当。PAV 40 小时老化后含有少量 RAP 的沥青共混物与 PAV 60 小时老化后的原始粘合剂相当。结果发现，经受 RTFO、PAV 20 小时老化、PAV 40 小时和 PAV 60 小时老化的粘合剂的流变学和化学性质与在 135°C 下经受 4 小时 STOA 协议、LTOA 的松散混合物的流变学和化学性质相当分别为 135°C 8 小时、135°C 12 小时的 LTOA 协议和 135°C 24 小时的 LTOA 协议。