基于经验模型的沥青混合料蠕变特性评价方法研究

Research on Asphalt Mixtures' Creep Characteristic Based on Experiential Model

重复荷载作用下沥青混合料永久变形可分为三个阶段,经验模型可以用于描述混合料蠕变曲线的前两阶段,第一、二阶段分界点F_S在工程中具有重要的应用。认为当取样间隔间△ε_p<3%时对应点为F_S,通过两种混合料不同试验条件,结果发现,截距(a)随温度及偏应力变化规律性不强;斜率(b)值随着偏应力增大而变大、随着围压增加而变小;F_S受围压的影响比较小,但随着偏应力的增加而变大。

Asphalt mixture＇ s permanent deformation can be divided into three stages under repeated load, experiential model can describe the first two stages of mixture＇ s creep curve, and the cut - off of first two stages Fs which play a good role in engineering application. It is deemed that Fs is occurred when below 3%. Under different test conditions two types mixtures＇ results indicated that intercept have a bad laws under different temperatures and deviator stress; slope b become larger along with higher deviator stress, and become smaller along with higher confining stress; however confining stress have little impact on Fs, and Fs become larger along with higher deviator stress.