现场存储SBS改性沥青的性能提升方法研究

Performance Improvement Methods of SBS Modified Asphalt During the Process of Site

针对SBS改性沥青在现场存储过程中的循环加热产生的性能衰减问题,结合室内试验,模拟存储过程中的四种典型工况,研究SBS改性沥青的针入度、软化点、延度、布氏旋转黏度和离析指标的衰减规律.同时,以外掺高掺量SBS改性沥青和外掺自主研发的RE高黏改性剂作为性能提升方法,研究最不利工况下两种性能提升方法对SBS改性沥青性能的恢复效果.试验结果表明,循环加热次数越多,不同循环加热存储工况之间的温度越高、时间越长,针入度、软化点、延度、布氏旋转黏度降低幅度越大,离析增加越明显;其中,延度、软化点和离析影响程度最为严重.在最不利工况下,外掺高掺量SBS改性沥青的恢复效果不理想;外掺RE高黏改性剂对老化SBS改性沥青的性能提升效果较为明显,延度、软化点和离析的变化幅度较大.当高黏改性剂的掺量达到5%时,老化SBS改性沥青延度、软化点和离析均已经达到了养护工程对SBS改性沥青的要求.

In order to deal with the problem that the properties attenuation of SBS modified asphalt caused by cyclic heating storage in the construction process,combined with laboratory tests,four typical working storage conditions are simulated to study the attenuation law of penetration,softening point,ductility,brookfield rotational viscosity and segregation of SBS modified asphalt.At the same time,by adding high content SBS modified asphalt and RE high viscosity modifier as SBS modified performance improvement methods,we study the recovery effect of two performance improvement methods on SBS modified asphalt under the most unfavorable conditions.The test results show that the more the cycle heating times are,the higher the temperature and the longer the time between different cycle heating storage conditions,the greater the reduction of penetration,softening point,ductility and brookfield rotational viscosity,and the more obvious the increase of segregation would be.Especially,the impacts of ductility,softening point and segregation are the most serious.Under the most unfavorable condition,the recovery effect of high content SBS modified asphalt is not ideal.However the performance of aging SBS modified asphalt is obviously improved by adding RE high viscosity modifier,the ductility,softening point and segregation change greatly.When the content of RE high viscosity modifier reaches 5%,the ductility,softening point and segregation of aged SBS modified asphalt can meet the requirements of maintenance engineering for SBS modified asphalt.