改性沥青混合料动态模量的多影响因素分析

Analysis of the Factors Influencing Dynamic Modulus of Modified Asphalt Mixtures

为探明多因素作用下沥青混合料力学性能,采用UTM-25万能试验机测定添加3种外加剂(橡维联、抗车辙剂和PR-Module(PR.M))的混合料动态模量,研究其与外加剂、温度和频率的作用规律。结果表明:3种外加剂均可有效提升混合料力学性能,橡维联体现在改善其粘弹特性,抗车辙剂和PR.M表现于调节其内部嵌挤作用。5种沥青混合料的抗变形能力均随温度升高或频率降低而下降,但同时掺加橡维联和抗车辙剂可有效缓解其衰减趋势。较基质沥青混合料,频率变化对改性沥青混合料的影响程度更大,说明其弹性更强,抵抗高温变形的能力更优。温度升高导致不同沥青混合料相位角相异,且混合料承受荷载的主要因素改变,由低温时粘结力为主,过渡到高温时内部嵌挤作用为主。

The paper aims to investigate the mechanical properties of asphalt mixtures under the influence of multi-factors.The dynamic modulus of the mixtures with three kinds of additives(rubber dimensional joint,anti-rutting agent and PR-Module(PR.M))was determined with a UTM-25 universal testing machine,and the effects of additives,temperature and frequency on the mechanical properties were investigated.The results show that all the three additives can effectively improve the mechanical properties of the mixtures,with the VLB improving the viscoelastic properties and the rutting inhibitor and PR.M regulating the internal embedding effects.The deformation resistance of the five asphalt mixtures decreases with an increase in temperature or a decrease in frequency,but the decreasing trend can be effectively alleviated by the simultaneous addition of VLB and the rutting inhibitor.Changes in frequency has a greater influence on the modified asphalt mixture than on matrix asphalt mixture,indicating that it is more elastic and has a better ability to resist high temperature deformation.As the temperature increases,different asphalt mixtures have different phase angles,and the main load bearing factors of the mixtures change from the bond at low temperature to the internal embedded extrusion at high temperature.