矿质混合料性能对沥青混合料动态模量的影响

摘要

为了解决沥青混合料高温性能不足的问题,研究了矿质混合料性能对沥青混合料动态模量的影响。以AC-20C型沥青混合料为背景,根据贝雷法3个参数进行了矿质混合料配合比正交试验设计,得到9种不同的矿质混合料级配,并以加州承载比( California bearing ratio,CBR)和振实间隙率为指标,对矿质混合料性能进行了评价,从中选出矿质混合料性能差异明显的3种级配,进行了沥青混合料的配合比设计。进而在不同温度和加载频率条件下,开展了3种级配沥青混合料的动态模量试验。依据试验结果,分析了矿质混合料性能对沥青混合料动态模量的影响。研究表明：高温条件下矿质混合料性能对沥青混合料的动态模量有较大影响,低温时矿质混合料性能对动态模量的影响不明显。通过优化矿质混合料性能,可以显著改善沥青混合料的高温性能。具有较高CBR值和较低振实间隙率的矿质混合料,对应的沥青混合料具有较好的高温性能。%In order to solve the problem of high temperature performance of asphalt mixture, an investigation into the influence of mineral mixture performance on the dynamic modulus of hot mix asphalt (HMA) was conducted. Nine various AC-20C gradations were determined in accordance with a Bailey method parameters based on orthogonal experimental design. The performances of the mineral mixtures with each gradation were evaluated by using the California bearing ratio ( CBR) and the voids of vibrated aggregate ( VVA ) in laboratory. Three gradations with significantly different mineral mixture performances were picked out to make HMA. Then, the dynamic moduli of HMAs corresponding to each of the 3 gradations were tested under multiple temperatures and loading frequencies. The influence of mineral mixture performance on the dynamic modulus of HMA was analyzed in accordance with the experimental results. The results show that the mineral mixture performance has significant influence on the dynamic modulus of HMA at high temperature, while has almost no influence at low temperature. The high temperature performance of HMA can be improved through investigating the CBR and VVA of aggregate in design. Higher CBR and lower VVA imply better high temperature performance of HMA.