高寒大温差下SBS/橡胶粉复合改性沥青路面温度应力分析

Temperature Stress Analysis of Styrene Butadiene Styrene Block Copolymer/Rubber Powder Composite Modified Asphalt Pavement Under High Cold and Large Temperature Difference

为了研究不同沥青结合料在高寒大温差下路面结构温度应力的变化规律,选取三种沥青结合料(基质沥青、SBS改性沥青和SBS/橡胶粉复合改性沥青)与三种级配类型(SMA-13、AC-13和AC-16)的混合料,室内测试不同沥青混合料试件的热物性参数和力学参数,采用有限元软件模拟沥青路面结构的温度应力,分析不同降温速率、初始温度场和周期性温度场作用下路面结构的温度应力变化规律,并将数值结果与冻断试验结果进行了对比。结果表明,边界条件不同,数值计算结果与冻断试验结果差异甚大;SBS/橡胶粉复合改性沥青具有最好的抗裂能力,温度应力变化周期滞后于气温变化,应变变化周期滞后于应力变化;路面开裂是温度应力累积、能量耗散的结果。

In order to study the variation law of pavement structure temperature stress of different asphalt binders under high cold and large temperature difference,three asphalt binders(SK90,SBS、SBS/Rubber Powder Composite Modified)and three grading types(SMA-13,AC-13 and AC-16)are selected to test the thermal physical and mechanical parameters of different asphalt mixture specimens indoors,and the temperature stress of asphalt pavement structure is simulated with finite element software to analyze different cooling rates.The variation law of temperature stress of pavement structure under the action of initial temperature field and periodic temperature field is compared with the results of freezing test.The results show that the results of numerical calculation are quite different from those of freezing test due to different boundary conditions;The composite modified asphalt has the best crack resistance,the temperature stress change cycle lags behind the temperature change,and the strain change cycle lags behind the stress change;The pavement cracking is a process of thermal stress accumulation and energy dissipation.