SiO_(2)气凝胶/反应性弹性体三元共聚物/多聚磷酸复合改性沥青流变性能与改性机理

Rheological properties and modification mechanism of SiO_(2) aerogel/reactive elastomer terpolymer/Polyphosphoric acid composite modified asphalt

为探究反应性弹性体三元共聚物(RET)、多聚磷酸(PPA)和SiO_(2)气凝胶(SG)复合改性沥青的流变性能,首先利用三大指标试验确定3种改性剂掺量;通过DSR、BBR、MSCR试验分析改性沥青高、低温性能及抗永久变形性能;借助傅里叶变换红外光谱试验、荧光显微试验和扫描电镜试验研究沥青改性机理和微观特性。结果表明:RET、PPA和SG的掺入提升了沥青高、低温性能。相比于原样沥青,复合改性沥青复数剪切模量提升了170%;-12℃时,蠕变劲度减小35 MPa,蠕变速率加快21.3%。气凝胶与两种聚合物以物理共混为主,改性过程生成新的吸收峰,气凝胶改善了沥青界面的相容性,且改性剂颗粒分散均匀,提高了沥青路用性能。

In order to investigate the rheological properties of the modified asphalt compounded with reactive elastomer terpolymer(RET),polyphosphoric acid(PPA)and SiO_(2) aerogel(SG).Firstly,the three modifier doping amounts were determined by using the three index tests;the high and low temperature properties and permanent deformation resistance of the modified asphalt were analyzed by DSR,BBR and MSCR tests.Fourier transform infrared spectroscopy,fluorescence microscopy and scanning electron microscopy were used to study the modification mechanism and microscopic properties of asphalt.The results showed that the incorporation of RET,PPA and SG improved the high and low temperature performance of the asphalt.Compared with the as-built asphalt,the complex shear modulus of the composite modified asphalt increased by 170%;creep stiffness decreased by 35 MPa at-12℃and creep rate increased by 21.3%.The aerogel and the two polymers were mainly physically blended,and the modification process generated new absorption peaks.The aerogel improved the compatibility of the asphalt interface,and the modifier particles were uniformly dispersed,which improved the asphalt road performance.