重复荷载下沥青混合料幂函数模型参数研究

Research of asphalt mixtures' parameter under repeated load based on power model

重复荷载永久变形试验在模拟现场车辙时更加合理,永久应变曲线可以用幂函数模型ε_p=αN^b进行拟合,拟合时数据取值范围为[N_lb,N_(ub)]=[60,C×Fn_(10)]。Fn能够区分混合料抗车辙性能,和现场车辙对比统计分析,发现b、ε_(2000)、ε_(5000)也能在一定程度上反映混合料抗车辙性能。通过对Sup20混合料平行试验结果分析发现:参数b变异系数最小,与流动数Fn的相关性较高为0.8067;虽然ε_(5000)与现场车辙的相关性好于ε_(2000),但从室内重复荷载永久变形试验结果看,ε_(2000)比ε_(5000)更能体现混合料蠕变性能。

Repeated load permanent deformation test is more rational in evaluating permanent deformation curve can be simulated with, the range of data using simulating spot rut depth, and permanent deformation curve is [ Nlb, Nub ] = [ 60, C × Fn10 ] . Fn can distinguish different mixtures, and the statistical resuits indicate that parameters b, ε2000 and ε5000 can also reflect mixtures＇ rutting resistance performance. The parallel tests of Sup20 indicate that b has least CV value, and the correlative coefficient is 0. 806 7 ; although ε5000 has better relativity with ε2000 in describing spot rutting, however, ε2000 is more suitable than ε5000 in repeated load permanent deformation test.