微波活化胶粉改性沥青的流变性能研究

Study on Rheological Properties of Microwave Activated Crumb Rubber Modified Asphalt

选取自行车、小轿车和卡车三种典型的废旧橡胶轮胎,针对微波活化对不同类型橡胶粉的作用效果进行了研究.采用微波辐照的方法对胶粉进行活化,分别制备了三种轮胎的橡胶粉及所对应的橡胶改性沥青,并将制备的样品分为活化和未活化两组.利用扫描电子显微镜(SEM)和傅里叶变换红外光谱分析仪(FTIR)分析微波活化前后橡胶粉的表面形貌及其结构,利用动态剪切流变仪(DSR)和弯曲梁流变仪(BBR)研究微波活化前后橡胶改性沥青的流变性能.结果表明,活化后橡胶粉的表面粗糙度增加,并且打断了胶粉中的S-C键和S-S键,可以起到反硫化的作用,使得胶粉表面活性增强,颗粒形貌更加蓬松,与沥青结合更加稳定;活化后橡胶改性沥青的复合模量增加、相位角减小,并且不同目数的同类胶粉改性沥青的复合模量和相位角趋于一致,说明微波活化可以有效改善橡胶改性沥青的流变性能,同时可以一定程度的消除颗粒的尺寸效应.

Three typical waste tires from bicycle,passenger-car and truck were selected to analyze the effect of microwave activation on different types of crumb rubber.The crumb rubbers were activated by microwave irradiation.Three kinds of crumb rubbers and the corresponding rubber modified asphalt were prepared respectively.The prepared samples were divided into the activated group and nonactivated group.The surface morphology and structure of the crumb rubber before and after microwave activation were analyzed by scanning electron microscopy（SEM）and Fourier transform infrared spectroscopy（FTIR）.The dynamic shear rheometer（DSR）and bending beam rheometer（BBR）were used to analyze the rheological properties of crumb rubber modified asphalt before and after microwave activation.The results indicate that the surface roughness of the crumb rubber particles after activation increases,and the S-C bond and S-S bond in the crumb rubber are interrupted,which has the effect of anti-vulcanization.The surface activity of the powder is enhanced and the morphology of the particles is more fluffy,making the combination with asphalt more stable.After activation,the composite modulus of crumb rubber modified asphalt increases and the phase angle decreases.The composite modulus and phase angle of the same type of crumb rubber modified asphalt with different particle sizes are similar,which shows that the microwave activation can improve the rheological properties of the rubber modified asphalt and eliminate the grain size effect to a certain extent.