苯乙烯-丁二烯嵌段共聚物与废橡胶粉复合改性高黏沥青及混合料性能研究

为了评价高黏改性剂对沥青性能的影响,采用高速剪切法制备了苯乙烯-丁二烯嵌段共聚物(SBS)改性沥青、废橡胶粉改性沥青和两种SBS/橡胶粉复合改性高黏沥青。通过三大指标试验、黏度试验、高温车辙试验和低温小梁弯曲试验,研究了高黏沥青的高低温性能、感温性能及沥青混合料路用性能。结果表明:4种改性沥青的高低温性能随各自改性剂掺量的增加逐渐提高,掺加10%北美岩沥青或2.5%多聚磷酸(PPA)的高黏沥青感温性能更稳定,较大幅度提升了黏度值,高温性能改善明显;掺加2.5%PPA的高黏沥青及其混合料能够更好地抵抗高温条件下的性能衰减,保证了使用效果,更适用于温度较高地区;掺加10%北美岩沥青的高黏沥青及其混合料在低温条件下性能良好,推荐在低温地区使用。

Study on property of SBS and waste rubber powder modified high-viscosity asphalt and its mixture

In order to evaluate the effect of high-viscosity modifiers on asphalt properties,high speed shear method was used to prepare SBS modified asphalt,waste rubber powder modified asphalt and two SBS/rubber powder composite modified high-viscosity asphalt.The high-temperature performance,low-temperature performance and temperature-sensing performance of the high-viscosity asphalt and the road performance of the asphalt mixture were studied through three major index tests,viscosity test,high-temperature rutting test and low-temperature beam bending test.The results shown that the high-temperature performance and low-temperature performance of the four modified asphalts gradually increased with the increase of the respective modifier content.The high-viscosity asphalt mixed with 10%North American rock asphalt or 2.5%polyphosphate PPA was more stable in temperature sensitivity.The viscosity value was greatly improved,and the high-temperature performance was significantly improved.The highviscosity asphalt and its mixture with 2.5%PPA can better resist the performance degradation under high temperature conditions,ensured the use effect and was more suitable for areas with higher temperature.High-viscosity asphalt and its mixture mixed with 10%North American rock asphalt had good performance under low temperature conditions,and recommended to be used in low temperature areas.