老化SBS改性沥青二次改性再生工艺及机理研究

Re-modification Recycling Process and Mechanism of Aged SBS Modified Asphalt

为研究老化SBS改性沥青的二次改性再生效果,比较不同工艺对再生效果的影响,首先通过常规试验、SHRP试验选择恰当的SBS改性沥青老化模拟方式,然后对添加SBS改性剂、新沥青进行再生的3种工艺展开研究,并借助红外光谱试验分析不同掺加顺序对老化SBS改性沥青再生效果的影响,确定了改性剂及新、旧沥青的最佳比例和最佳工艺。结果表明:采用RTFOT试验进行老化模拟更加方便、科学,RTFOT试验5h获得的改性沥青指标与服务年龄为7年的SBS改性沥青一致;SBS改性剂、新沥青添加顺序与老化沥青再生效果关系密切,先将SBS改性剂和新沥青混合制备改性沥青,再将改性沥青与老化沥青混合的工艺可使再生沥青性能最佳,其中SBS最佳掺量为4%,新、旧沥青质量比为2。

To study the re-modified recycling effect of SBS modified asphalt and compare the influence of different recycling process,the SBS modified asphalt aging simulation method was selected by the routine test and the SHRP test firstly in this paper.Then three kinds of processes were researched about recycling method that adding SBS modifier and new asphalt.On the basis of infrared spectrum test,the influence of different processes on recycling effect of aging SBS modified asphalt were analyzed.Finally,the optimal ratio and best process were determined,which including the content of SBS modifier,the ratio of new to old asphalt.The results showed that using RTFOT experiment in aging simulation is more convenient and scientific.The indicators of SBS modified asphalt after five hours RTFOT experiment accords with the asphalts applied for seven years.And the addition order between the SBS modifier and the new asphalt is closely related to the recycling effect of aging asphalt.The best process is that preparing modified asphalt with SBS modifier and new asphalt firstly,then mixing the modified asphalt and aging asphalt,with 4%SBS modifier and the ratio of new and old asphalt of 2.