湖沥青改性沥青及沥青混合料低温性能研究

The Low Temperature Performances of Lake Asphalt Modified Asphalt and Asphalt Mixture

采用延度试验和弯曲梁流变试验对不同TLA掺量改性沥青的低温性能进行研究,并利用差热扫描（DSC）研究不同TLA掺量的改性沥青组分在温度变化过程中的状态变化,最后通过低温小梁弯曲试验对混合料的低温性能进行评价.结果表明：随着TLA的掺量增加,湖沥青改性沥青的延度值逐渐减小、蠕变劲度S值和玻璃化转变温度Tg逐渐增大,TLA改性沥青的低温抗开裂能力变差,掺加35%TLA的改性沥青混合料的破坏应变与SBS改性沥青混合料破坏应变值相差不大;三种TLA掺量的湖沥青改性沥青的吸热峰都出现在125~145℃之间,加入TLA后,吸热峰位置的变化说明沥青组分的存在方式、数量以及相态转化方式发生了变化.

The low temperature performance of modified asphalt with different TLA content was studied by usingthe ductility test and bending beam rheometer,and the state change of the modified asphalt mixture with differentTLA content was studied by differential thermal scanning（DSC）. Then the low temperature performance of the mixturewas evaluated by low temperature bending test. The results show that, with the increase of TLA content,the ductilityof the asphalt decreased gradually,the creep strength S value and the glass transition temperature Tggraduallyincreased,indicating the low temperature cracking resistance of TLA modified asphalt decreased. The failure strainof asphalt mixture with 35%TLA has little difference with that of SBS modified asphalt mixture. The endothermicpeak of the three kinds TLA modified asphalt was observed at 125-145 ℃. After the addition of TLA,the change ofthe position of the endothermic peak indicated that there was a change in the existing mode,quantity and phasetransformation of asphalt.