不同来源橡胶粉对橡胶沥青性能影响
Performance of asphalt binders modified by different crumb rubbers

为了探究橡胶粉来源及组成对橡胶沥青性能的影响，选用重载卡车轮胎、小轿车轮胎、橡胶鞋底、轮胎胎面和轮胎圈口，采用常温粉碎方法制备5种橡胶粉。通过热重分析方法对5种橡胶粉的成分进行分析，得出各橡胶粉中主要成分及含量。采用甲苯可溶物含量试验，分析橡胶粉在沥青中的降解程度。在此基础上，分别采用弹性恢复试验、动态剪切流变仪（DSR）、低温弯曲梁流变仪（BBR）和测力延度仪对5种橡胶沥青的弹性恢复率、高低温流变性和低温抗裂性能进行评价。研究结果表明：不同来源的胶粉具有不同的成分，轮胎和鞋底橡胶主要包含炭黑和硫化橡胶，硫化橡胶中天然橡胶和合成橡胶的比例存在明显差异；在高温剪切条件下，5种橡胶的甲苯可溶物含量（质量分数，下同）均大于39%，表明橡胶粉在沥青中均存在不同程度的降解行为；由天然橡胶制成的鞋底橡胶粉改性沥青的甲苯可溶物含量为50.97%，明显高于其他几种橡胶沥青；重载卡车轮胎胶粉的甲苯可溶物含量高于小轿车轮胎胶粉，轮胎圈口胶粉的甲苯可溶物含量最低，其在沥青中的解聚过程最微弱；轮胎中的胎圈胶属于硬质胶，其制备的橡胶沥青的弹性恢复性能明显低于其他软质橡胶，重载卡车轮胎胶粉改性沥青的高低温流变性能改善效果最为明显。橡胶粉在沥青中的解聚和溶胀程度共同影响橡胶沥青的性能。
To evaluate the effect of the source and compositions of rubber powder on the performance of rubber asphalt, five rubber powers which crushing at room temperature were obtained from a heavy truck, sedan tire, sole rubber, tire tread, and tire bead. The components content of rubber hydrocarbons were analyzed by thermogravimetric analysis. The degradation degree of rubber powder in asphalt was analyzed by the toluene soluble content test. Further, an elastic recovery test, dynamic shear rheometer （DSR）, low temperature bending？？beam rheometer（BBR）, and force？？ductility test were employed to evaluate the elastic recovery rates, high？？low temperature stabilities, and low？？temperature crack resistances of the five types of rubber asphalt. The results show that the rubber powders of different sources consist of different components. The rubber of tire and sole rubber is mainly composed of carbon black and vulcanized rubber. The proportion of natural and synthetic rubbers is significant differences of vulcanized rubber. Under high？？temperature shear conditions, the toluene soluble content (mass fraction, the same below) of the five rubber？？asphalts is more than 39%. This indicates that the five rubber powders demonstrate obvious degradation behavior. The toluene soluble content of the sole rubber powder modified asphalt can reach 50.97%, which is significantly higher than those of other rubber asphalts. The toluene soluble content of the heavy truck asphalt is larger than that of the sedan tire. The lowest toluene soluble content is noted for the tire bead, which is the weakest in the process of asphalt depolymerization. The tire bead rubber powders demonstrate larger stiffness, resulting in the rubber recovery being significantly lower than the other soft rubbers. The high and low temperature rheological properties of the heavy？？duty truck tire rubber powder modified asphalt is significantly. The degree of depolymerization and swelling of the rubber powder in the asphalt affects the performance of the rubber asphalt