不同疲劳试验中改性沥青混合料疲劳性能对比

Comparison of Fatigue Properties of Modified Asphalt Mixtures in Different Fatigue Tests

使用四点弯曲疲劳试验(4PB)、两点梯形梁疲劳试验(2PB)和overlay tester(OT)试验3种试验方法,对工程上常用的7种沥青混合料疲劳性能进行了测试.结果表明:在3种疲劳试验中,掺加6%(质量分数,下同)SBS的改性沥青混合料疲劳性能均较好,同时掺加10%TB胶粉和3%SBS的改性沥青混合料、掺加4.5%SBS的改性沥青混合料和同时掺加4.5%SBS及0.4%多聚磷酸(PPA)的改性沥青混合料疲劳性能均一般,掺加3%SBS的改性沥青混合料疲劳性能较差,温拌剂改性沥青混合料和埃索基质沥青混合料的疲劳性能最差;提高SBS掺量可以有效地提高沥青混合料的疲劳性能;添加TB胶粉和PPA可以在不同程度上提高SBS改性沥青混合料的疲劳寿命,但其对疲劳性能的影响力逊于SBS;不同试验方法中沥青混合料疲劳性能的排序具有一致性,具体排序稍有不同.

Four-point bending beam fatigue test(4PB),two-point bending beam fatigue test(2PB),and overlay tester(OT)were used to evaluate the fatigue properties of seven kinds of asphalt mixtures that are usually used in engineering.The result shows that in three kinds of fatigue tests,the fatigue performances of 6%(by mass,the same below)SBS modified asphalt mixture is good,the fatigue performances of 10%TB+3%SBS modified asphalt mixture,4.5%SBS modified asphalt mixture and 4.5%SBS+0.4%polyphosphoric acid(PPA)modified asphalt mixture are fine,and the fatigue performance of 3%SBS modified asphalt mixture is inferior.The fatigue performances of warm mixing agent modified asphalt mixture and ESSO bitumen are the worst.The increase of SBS content can effectively improve the fatigue performance of the asphalt mixture.The fatigue performance of the SBS modified asphalt mixture can be improved by the addition of TB and PPA,but the effect on fatigue performance is not as big as that of increasing SBS content.In different tests,the ranking of fatigue performance of asphalt mixture is similar,and the specific ranking is slightly different.