硬质沥青混合料动态、静态模量的试验研究

Experiment Study on Resilient and Complex Modulus of Hard Grade Asphalt Mixture

采用针入度为10/20的硬质沥青和石灰岩集料制备高模量沥青混合料,同时选择了一种PG76—22的SBS改性沥青,进行性能对比。基于体积法的配合比设计完成后,采用马歇尔稳定度试验、车辙试验、三点弯曲试验、间接拉伸试验来评价硬质沥青混合料的高温性能、低温性能和水稳定性。静态回弹模量与动态复数模量均采用单轴压缩试验来完成,采用不同的加载模式,回弹模量采用7级静态加载,复数模量采用不同频率的正弦波动态加载。深入研究了温度对两种模量的影响。基于反曲函数绘制了动态模量主曲线,同时采用Cole-Cole平面分析硬质沥青混合料的黏弹特征。研究认为,硬质沥青可以制备抗车辙性能优异的高模量沥青混合料,相同温度下,硬质沥青混合料的复数模量均高于SBS改性沥青混合料,但37.8℃以上温度时,硬质沥青混合料的黏性流动比例较大。

A hard grade asphalt Pen 10/20 and limestone aggregate are used to produce the high modulus asphalt mixture（HiMAM）-AC20.A SBS modified asphalt PG70—22 is compared with Pen 10 /20 asphalt.After mix design is finished,the basic properties of this mixture are tested including Marshall Stability,dynamic stability,rutting depth,bending strain,indirect tensile strength ratio and so on.The resilient modulus and complex modulus of hard grade asphalt mixture（HaGAM） are investigated by means of the uniaxial compression test.Three temperatures are adopted for resilient modulus and five temperatures are adopted for complex modulus with the different frequencies.Master curves are constructed by regressions for a sigmoidal function.Cole-Cole plane is used to analyze viscoelastic property of HaGAM.The results indicate that this hard grade asphalt can be used to produce HiMAM with the excellent rutting resistance.Complex moduli of HaGAM are higher than SBS asphalt mixture at the same temperature,but viscous flow of HaGAM is easier than SBS-AM below 37.8 ℃.