为评价高模量温拌改性剂对基质沥青基本指标和疲劳性能的影响,在 70#基质沥青中掺入不同剂量改性剂,采用动态剪切流变仪(DSR)对试验沥青进行动态扫描试验研究.首先制备了不同掺量高模量温拌改性剂改性沥青,随后评价其基本性能,并通过布氏粘度试验分析不同沥青的拌和温度与压实温度;再采用DSR 对不同掺量高模量温拌改性剂改性沥青进行线性振幅(LAS)扫描试验和时间扫描试验.通过 LAS 试验和粘弹性连续损伤(VECD)模型分析不同掺量(0%,2%,3%,4%)改性沥青和 SBS 改性沥青的疲劳特性;基于动态扫描试验,应用耗散能原理探究不同掺量改性剂对沥青疲劳性能,同时把不同掺量改性 70#沥青与 SBS改性沥青的试验结果进行比对,并分析了改性剂的作用机理.试验结果表明:随着高模量温拌改性剂掺量增加,软化点增加,针入度和延度减少,3%掺量改性沥青软化点稍优于SBS沥青;改性沥青粘度随着改性剂增加先减后增,改性后沥青的拌和、碾压温度与 70#基质沥青相当,均远小于 SBS 改性沥青,即改性后的沥青有良好的温拌效果;高模量温拌改性剂可不同程度提高沥青的疲劳性能,合适掺量改性沥青疲劳性能可与SBS改性沥青相当,高模量温拌改性剂的建议掺量为 3%;研究结果将为高模量温拌改性路面材料工程应用提供参考.
Study onthe effect of high modulus&warm modifier on asphalt physical index and fatigue performance
In order to investigate physical index and the fatigue performance of base asphalt modified by different high modulus&warm agent content,the dynamic sweep tests for 70#base asphalt with different high modu-lus&warm agent content were carried out using dynamic shear rheometer(DSR).Firstly,modified asphalt with different agent content was prepared,and then the basic performance of the modified asphalt with different agent content was evaluated.The mixing temperature and compaction temperature of asphalts contained differ-ent modifier content were compared by the Brookfield viscosity test.Then the rheometer was used to analyze the fatigue properties of modified asphalt with different modifiers(0%,2%,3%,4%)content and SBS modified asphalt based on linear amplitude sweep test and viscoelastic continuum damage(VECD)model.Finally,based on the dynamic sweep test,the dissipated energy principle was applied to investigate the fatigue performance of asphalt with different dosage modifiers.At the same time,the test results of different dosage-modified 70#as-phalt and SBS-modified asphalt were compared with each other,and the mechanism of the modifier's action was analyzed.The test results show that with the increasing of additive modifier,the softening point of asphalt has improved,while the penetration and ductility have decreased.In comparison,the softening point of modified as-phalt with modifier 3%content is slightly better than that of SBS modified asphalt.With the increase of modifi-er content,the viscosity of modified asphalt decreases first and then increases,the mixing and rolling tempera-ture of asphalts with modifier is equivalent to that of 70#asphalt,which is far less than that of SBS modified asphalt.That is to say,modifiers can have a certain warm mixing effect.The fatigue performance of modified asphalt with appropriate modifier content is better than that of SBS modified asphalt,and the recommended content of high modulus&warm modifier is 3%.The research results will provide a theoretical basis for the road engineering of high modulus&warm modifier new pavement materials.
万方数据
维普
