特立尼达湖沥青/热塑性丁苯嵌段共聚物复合改性沥青混合料改性机理及性能

Modification Mechanism and Performance of Trinidad Lake Asphalt/Styrene-Butadiene-Styrene Composite Modified Asphalt Mixture

为弥补特立尼达湖沥青(Trinidad Lake asphalt,TLA)在某些性能方面的不足,考虑加入热塑性丁苯嵌段共聚物(styrene-butadiene-styrene,SBS)改性剂进行改善。首先,从微观及化学组成分析了TLA的改性机理。然后,对TLA和TLA/SBS复合改性沥青性能分别进行了测试,并对不同TLA掺量下的TLA/SBS沥青混合料进行了动稳定度、稳定度、水稳性、低温抗裂性、抗疲劳、动态模量等指标的试验。结果表明,复合改性显著地改善了基质沥青的软化点、延度、黏度指标,一般在45%以上;复合改性后的沥青混合料各项指标都得到了明显的提升,特别是高、低温稳定性、抗疲劳性能、动态模量提升幅度在13%~86%,具有良好的路用性能。最后,得出了沥青混合料中的SBS最佳掺量应为5%,TLA掺量为20%。

To make up for the deficiency of Trinidad Lake asphalt(TLA)in some aspects,it was considered to add styrene-butadiene-styrene(SBS)modifier.Firstly,the modification mechanism of TLA was analyzed from the microscopic and chemical composition.Then TLA and TLA/SBS composite modified asphalt were tested respectively,and the dynamic stability,stability,water stability,low temperature cracking resistance,fatigue resistance,dynamic modulus and other indexes of TLA/SBS asphalt mixture with different TLA content were tested.The results show that the softening point,ductility and viscosity of base asphalt are significantly improved by the composite modification,generally over 45%.After the composite modification,various indexes of asphalt mixture have been significantly improved,especially the high and low temperature stability,anti-fatigue performance,dynamic modulus increase range of 13%~86%,with excellent pavement performance.Finally,the optimal SBS content in asphalt mixture is 5%,and TLA content is 20%.