公路工程

为研究湖沥青(TLA)掺量对TLA改性沥青温度敏感性和微观结构的影响,分别对TLA改性沥青(湖沥青掺量分别为0%、15%、25%和35%)进行粘度试验和动态剪切流变(DSR)试验,采用粘温指数(VTS)和复数模量指数(GTS)对TLA改性沥青的温度敏感性进行评价,并采用扫描电镜(SEM)试验对TLA改性沥青的微观结构进行研究。试验结果表明:TLA改性沥青的VTS绝对值随着湖沥青掺量的增加而逐渐增大,当湖沥青的掺量为35%时,TLA改性沥青的VTS绝对值达到3.606,比基质沥青增加了4.43%,说明湖沥青的掺加使得70#沥青的温度敏感性增大。TLA改性沥青结合料内部的存储模量、损耗模量和CNI值均呈现逐渐增大趋势,湖沥青的掺加对TLA改性沥青产生不利影响。当湖沥青的掺量在25%~35%时,基质沥青的结构变化明显,较大的湖沥青掺量使得TLA改性沥青的温度敏感性增大。

In order to study the effect of TLA content on the temperature sensitivity and microstructure of TLA modified asphalt,the viscosity and dynamic shear rheology(DSR) tests were carried out on TLA modified asphalt(content of TLA was 0%,15%,25% and 35%),the temperature sensitivity of TLA modified asphalt was evaluated by viscosity temperature index(VTS) and complex modulus index(GTS),and the microstructure of TLA modified asphalt was studied by SEM. The results show that with the increase of lake asphalt content,the VTS absolute value of TLA modified asphalt increases gradually,When the content of lake asphalt is 35%,the VTS value of TLA modified asphalt is up to 3. 606,which is increased by about 4. 43% compared with that of base asphalt,indicating that the addition of Lake Asphalt increases the temperature sensitivity of base asphalt. The storage modulus,loss modulus and CNI value of the TLA modified asphalt binder show a gradually increasing trend,indicating the addition of lake asphalt has an adverse effect on TLA modified asphalt. When the lake asphalt content is 25%~ 35%,the structure changes of the base asphalt is obvious. So the larger lake asphalt content will increase the temperature sensitivity of TLA modified asphalt.