Impact of viscosity modifier on asphalt properties used for bus rapid transit lanes in Chengdu

In order to find the effect of different viscosity modifier dosages on asphalt binder＇s performance in bus rapid transit lanes in the city of Chengdu, three different viscosity modifiers were analyzed： TAFPACK-super （TPS）, high-viscosity additive （HVA） and road-science- technology （RST）, and four different asphalt binders were investigated through laboratory experiments. The percent- ages of the viscosity modifiers used were： TPS （0%, 8%, 10%, 12%, 14% and 16%） and RST and HVA （8% and 12%） depending on the type of asphalt binder. Technical indicators of modifier asphalt were tested through con- ventional and unconventional binder tests. It has been found out that only a percentage greater than or equal to 14% TPS is reasonable to achieve the requirement set by 20,000 Pa. s for the 60℃ dynamic viscosity on local #70 grade asphalt. The results indicate that conventional bin- ders did not meet the requirements of the 60℃ dynamic viscosity when 12% of TPS or HVA modifiers were used. In addition, the B-type styrene-butadienne-styrene （SBS） modified asphalt binder has better viscosity balance than the A-type SBS modified when 8% of each of the three different kinds of viscosity modifiers is used. Therefore, the B-type modified SBS thus appears to be a suitable choice in asphalt mixtures for bus rapid transit lane with the 60℃ dynamic viscosity.

石油树脂对高黏改性沥青性能的影响研究

针对高黏沥青存在的黏度高、泵送困难、存储稳定性差的问题,文章借助石油树脂自身的性能优势,以其为改性材料,考察了石油树脂掺量对高黏沥青软化点、针入度、5℃延度、135℃运动黏度、60℃动力黏度和存储稳定性等指标的影响规律。结果表明,石油树脂的掺加可以改善高黏沥青的135℃运动黏度和存储稳定性,具有显著的节能减排效益。同时,石油树脂的加入对高黏沥青的高低温性能和黏附性均有不同程度的损伤。综合各项性能指标,建议石油树脂的最佳掺量为1.5%。