聚合物改性沥青及混合料高低温性能试验研究

胶粉改性沥青（CRMA）是将一定比例的废旧橡胶轮胎粉末加入基质沥青中而制成的一种高性能改性沥青。利用扫描电镜（SEM）对比观察了CRMA和SBS改性沥青及其混合料的外观形貌,发现橡胶粉及SBS改性剂都与沥青融合性良好,混合料中石料与CRMA沥青界面粘结性更好;通过动态剪切流变试验,得到温度和荷载作用频率对两种改性沥青流变性能的影响规律,证明CRMA具有更好的温度稳定性、低温变形能力和抗高温性能;通过小梁弯曲蠕变试验,研究了配合比相同的两种沥青混合料在-15、0、15、30和45℃5种温度下的流变特性,得到不同温度下的弯曲蠕变速率对比曲线,发现CRMA混合料比SBS改性沥青混合料具有更好的高、低温性能;通过对45℃下两种沥青混合料进行三轴压缩蠕变试验,证明CRMA沥青混合料具有更好的抗高温变形特性。

Experimental Study on the Performance of High and Low Temperature of Polymer Modified Asphalt and Mixture

Crumb rubber modified asphalt is a kind of modified asphalt when putting proportional crumb rubber into base asphalt. Scanning Electron Microscope（SEM） is used to observe CRMA,SBS modified asphalt and mixture. We can see rubber powder and SBS modifier has good fusion with asphalt. Interface bonding between aggregate and asphalt in CRMA mixture is better. The influence of temperature and load frequence to rheological properites of asphalt is studied by dynamic shear rheological experi- ment. Experimental results show, CRMA has better temperature stability,low temperature deformation ability and high temperature performance. The rheological properites of two asphalt mixture with same mix component is studied by trabecular bending creep test at - 15℃ ,0℃ ,15℃ ,30 ℃ and 45℃. The correlation curve of bending creep rate is obtained. It is proved, CRMA miature has better high and low temperature properites compare to SBS modified asphalt mixture. Moreover, triaxial compression creep test is carried on for two asphalt mixture at 45 ℃. We can see CRMA mixture has better resistance to high temperature deformation performance.