木质素纤维增强型透水性沥青稳定碎石疲劳研究

Fatigue performance of fiber-reinforced asphalt treated permeable base

为提高增强型透水性沥青稳定碎石(asphalt treated permeable base,ATPB)的抗裂性能和耐久性,以SBS改性沥青为胶结材料配制掺入木质素纤维的ATPB混合料——纤维增强型透水性沥青稳定碎石(fiber asphalt treated permeable base,FATPB),并制作不同木质素纤维掺量的FATPB-25梁式试件进行不同应力比下的四点弯曲疲劳试验。将木质素纤维掺量为0.3%的FATPB-25与普通的AC-25、ATB-25的疲劳性能进行对比分析,探究考虑失效概率的应力比与纤维掺量对疲劳寿命的影响。研究结果表明:纤维掺量为0.3%的FATPB-25的抗疲劳性能明显比普通的AC-25和ATB-25的高,可用作耐久型的透水性下面层或柔性基层;通过包含失效概率的双对数方程可以对FATPB-25的疲劳寿命进行预测。

In order to enhance the cracking resistance of asphalt treated permeable base(ATPB)and improve its durability,an ATPB mixture using SBS modified asphalt as cementing material and adding lignin fiber was designed(FATPB).Four point bending fatigue tests were carried out on the beam specimens of FATPB-25 with different fiber content under different stress ratios.The fatigue properties of FATPB-25 with 0.3%fiber content were compared with those of AC-25 and ATB-25,and the effects of stress ratio and fiber content on fatigue life considering failure probability were investigated.The results show that the fatigue resistance of FATPB-25 with 0.3%fiber content is obviously better than that of AC-25 and ATB-25,which can be used as a durable water-permeable underlayer or flexible base layer.The fatigue life of FATPB-25 can be expressed by the log-log equation with failure probability.