为探究青川岩沥青(Qingchuan rock asphalt,QRA)和 SBS 在桥面铺装中的应用,以 2%,3%SBS 和 5%,10%,15%QRA为改性剂,制备得到6 组QRA/SBS复合改性沥青(QRA/SBS composite modified asphalt,QSMA),综合研究QSMA基本路用性能、微观改性机理、高温流变性能和疲劳特性.结果表明,QRA能够提高QSMA软化点并降低针入度,SBS对提升QSMA的5℃延度有利.特征官能团显示QSMA与基质沥青含有相同烃类化合物,QSMA改性机理为物理改性.QRA和SBS掺量的增大能提高沥青的变形阻力,抑制沥青不可恢复形变的产生,进而提升QSMA抵抗高温车辙变形的能力.QRA和SBS的加入可提高沥青的劲度和弹性.QRA和SBS能提升沥青基体抵抗疲劳断裂的能力,表现出更小的应变依赖性和更好的抗疲劳性.综合三大指标、高温流变实验与疲劳实验结果,推荐最优掺量组合为3%SBS+15%QRA.
Abstract
In order to investigate the application of Qingchuan rock asphalt(QRA)and SBS in bridge deck paving,using 2%,3%SBS and 5%,10%,15%QRA as modifier,and prepares6 groups of QRA/SBS composite modified asphalt(QSMA),comprehensive study of QSMA basic road performance,micro-modification mechanism,high temperature rheological properties and fatigue characteristics.The results show that QRA can improve the softening point and reduce the penetration of QSMA,and SBS is benefi-cial to improve the 5℃ductility of QSMA.The characteristic functional groups show that QSMA and ma-trix asphalt contain the same hydrocarbon compounds,and the modification mechanism of QSMA is on physical aspect.The increase of QRA and SBS can improve the deformation resistance of asphalt,inhibit the generation of asphalt unrecoverable deformation,and then improve the ability of QSMA to resist high temperature rutting deformation.The addition of QRA and SBS can improve the strength and elasticity of asphalt.QRA and SBS can improve the resistance to fatigue fracture of the asphalt matrix.The ability of asphalt matrix to resist fatigue fracture,showing less strain dependence and better fatigue resistance.Com-bining the three major indexes,high temperature rheological test and fatigue test results,the optimal do-ping combination is recommended to be 3%SBS+15%QRA.
关键词
青川岩沥青/SBS/改性沥青/高温流变性能/疲劳性能
Key words
Qingchuan rock asphalt/SBS/modified asphalt/high-temperature rheological properties/fa-tigue properties
万方数据