废旧聚乙烯塑料改性沥青混合料耐老化性能分析

Analysis of Aging Resistance of Waste Polyethylene Plastic Modified Asphalt Mixture

【目的】分析废旧聚乙烯塑料(Polyethylene,PE)改性沥青混合料的耐老化性能。【方法】通过车辙试验、单轴贯入试验、低温弯曲试验、冻融劈裂试验和四点弯曲疲劳试验来评价老化前后不同类型沥青混合料的性能。【结果】试验结果表明:在短期和长期老化后,PE和SBS改性沥青混合料的动稳定度和贯入强度的增加幅度分别为12%~18%、25%~35%,水稳定性能和低温性能均满足规范要求;普通沥青混合料的动稳定度和贯入强度增加幅度分别为30%~35%、60%~70%。只有短期老化后的水稳定性能和低温性能才能满足要求。【结论】PE和SBS改性沥青混合料耐老化性能基本相当,且明显高于普通沥青混合料。PE改性剂可抑制或减少自由基的产生,能显著减缓改性沥青的氧化老化程度。

[Purposes]This paper aims to analyze the aging resistance of waste polyethylene modified as-phalt mixture.[Methods]The performance of different types of asphalt mixtures before and after aging was evaluated by rutting test,uniaxial penetration test,low temperature bending test,freeze-thaw split-ting test and four-point bending fatigue test.[Findings]The test results show that the dynamic stability and penetration strength of PE and SBS modified asphalt mixture increase by 12%~18%and 25%~35%respectively after short-term and long-term aging,and the water stability and low temperature perfor-mance meet the requirements of the specification.The dynamic stability and penetration strength of ordi-nary asphalt mixture increase by 30%~35%and 60%~70%respectively.Only the water stability and low temperature performance after short-term aging can meet the requirements.[Conclusions]The aging re-sistance of PE and SBS modified asphalt mixture is basically the same,and significantly higher than that of ordinary asphalt mixture.PE modifier can inhibit or reduce the production of free radicals,and can sig-nificantly slow down the degree of oxidative aging of modified asphalt.