冻融作用下沥青混合料抗反射开裂性能研究

Anti-reflection Cracking Performance of Asphalt Mixture under Freeze-Thaw Cycles

采用Overlay tester(OT)对大粒径透水沥青混合料(LSPM)进行多次冻融循环试验,分析了冻融循环作用下LSPM的抗反射开裂性能.结果表明:冻融循环作用对LSPM的抗反射开裂性能具有显著影响;OT试验能有效反映LSPM的抗反射开裂性能,可以用容许破坏次数和荷载损失率来共同评价LSPM抗反射开裂性能,采用指数模型能较好地表征和预测容许破坏次数随冻融循环次数的衰减状况;模拟冻融影响时应至少进行20次冻融循环;橡胶粉改性沥青和SBS改性沥青用于LSPM均具有良好的抗反射开裂性能,但SBS改性沥青混合料受冻融循环作用影响更大,粒径为301μm(60目)橡胶粉改性沥青混合料更适用于长期冻融地区的沥青路面.

Overlay tester(OT)was applied to simulate and analyze the anti-reflection cracking performance of large stone porous asphalt mixture(LSPM)after different number of freeze-thaw cycles.Results indicate that freeze-thaw cycle has a significant effect on anti-reflection cracking performance of LSPM.OT can well reflect the anti-reflection cracking performance of asphalt mixture.Load loss rate and tolerance failure times are put forward to evaluate the anti-reflection cracking performance.The exponential model is suitable to characterize and predict the attenuation of tolerance failure times.At least 20 freeze-thaw cycles are recommended for the test.Rubber powder modified asphalt mixtures and SBS modified asphalt mixture have good anti-reflection cracking performance for LSPM,however SBS modified asphalt mixture is more affected by freeze-thaw action.301μm(60 mesh)rubber powder modified asphalt mixtures is recommended for long-term freeze-thaw area.