ABSTRACT

Previous research studies have indicated that each bituminous component plays a different role in rheological properties of bitumen. However, a few literature studies focus on rheological parameters of bitumen at component level. This paper aims to investigate the intuitive influence of rheological parameters of maltenes on rheological properties of bitumen. Saturates, aromatics, resins and asphaltenes (SARA) were firstly separated from two base bitumens and Styrene–butadiene–styrene (SBS)-modified bitumen. Dynamic shear rheometer (DSR) was applied to characterise the rheological properties of three bitumens and their maltenes. Temperature and frequency sweep tests were conducted to obtain six rheological parameters, including complex modulus, phase angle, complex modulus index, rutting factor, fatigue factor and rheology cracking index. The results indicate that the elasticity of base bitumen in low-temperature stage is mainly provided by resins and aromatics compared with the sole contribution of aromatics in SBS bitumen. The promotion effect for enhancing anti-rutting ability of resins in base bitumen is superior to that of SBS bitumen. Saturates, with a rutting factor of less than 1 kPa, lead to a passive effect on deformation resistance at higher temperatures of bitumen. Maltenes show a different contribution rate of improvement of fatigue resistance in a descending order of saturates, resins and aromatics. Aromatics with superior cracking resistance contribute to the enhancement of ductility for bitumen in contrast to resins with a larger rheology cracking index. The intuitive analysis on maltenes will facilitate further investigation of the interaction mechanism for bitumen modification and rejuvenation so as to enhance rheological properties of bitumen.

摘要

先前的研究表明，每种沥青成分在沥青的流变特性中发挥着不同的作用。然而，一些文献研究集中在组分层面的沥青流变参数。本文旨在研究麦芽糖的流变参数对沥青流变特性的直观影响。首先从两种基础沥青和苯乙烯-丁二烯-苯乙烯 (SBS) 改性沥青中分离出饱和物、芳烃、树脂和沥青质 (SARA)。动态剪切流变仪 (DSR) 用于表征三种沥青及其软化蛋白的流变特性。通过温度和频率扫描测试，获得了复模量、相位角、复模量指数、车辙因子、疲劳因子和流变开裂指数6个流变参数。结果表明，低温阶段基础沥青的弹性主要由树脂和芳烃提供，而芳烃在 SBS 沥青中的贡献则单独存在。树脂在基础沥青中增强抗车辙能力的促进作用优于SBS沥青。车辙因数小于 1 kPa 的饱和油会在沥青较高温度下对变形抗力产生被动影响。Maltenes 对提高抗疲劳性的贡献率从高到低依次为饱和烃、树脂和芳烃。与具有较大流变开裂指数的树脂相比，具有优异抗裂性的芳烃有助于提高沥青的延展性。