季冻区橡胶粉与SBS复合改性沥青混合料性能及改性机理

Pavement performance and modified mechanism of rubber powder and SBS compound modified asphalt mixture in seasonal freezing region

为改善季冻区公路沥青路面病害突出的问题,通过对橡胶粉与SBS复合改性沥青混合料性能的系统研究,基于季冻区的特殊要求,确定了橡胶粉与SBS适宜的掺配比例,系统评价了复合改性沥青混合料的路用性能;通过扫描电镜、红外光谱以及差示扫描热量分析等试验方法,从微观角度分析了橡胶粉与SBS复合改性沥青的机理。研究结果表明：用于季冻区的橡胶粉与SBS复合改性沥青中,橡胶粉的推荐掺量为20%～23%,SBS推荐掺量为2.0%;橡胶粉与SBS复合改性沥青可大幅改善SMA以及AC型沥青混合料的路用性能,相比SBS改性沥青混合料,高温性能提升59%,低温性能提升幅度高达154%,冻断温度降低约18℃;橡胶粉与SBS复合改性沥青体系热稳定性较普通改性沥青好,这与其各成分间表面张力降低有关。

In order to improve the performance of asphalt pavement in seasonal freezing region,this paper did systematic study on road performance of rubber powder and SBS compound modified asphalt,and proposed the optimum mixing ratio of rubber powder and SBS compound modified asphalt according to special requirements of seasonal freezing region.Performance evaluation of rubber powder and SBS compound modified asphalt mixture was carried out.The modified mechanism of rubber powder and SBS compound modified asphalt was analyzed from the microscopic point of view based on the results of infrared spectroscopy and differential scanning calorimetry test data.The results show that the recommended dosage of rubber powder and SBS composite modified asphalt is 20%-23%,and the recommended dosage of SBS is 2.0%.Rubber powder and SBS composite modified asphalt can greatlyimprove the road performance of SMA and AC asphalt mixture.Compared with SBS modified asphalt mixture,the improvement of high temperature property reaches to 59%,the improvement of low temperature property reaches to 154%,and the breaking temperature in low temperature reduces by18℃.The system of rubber powder and SBS composite modified asphalt has good thermostability,which is related to the decrease of surface tension between the components.10 tabs,10figs,17 refs.