EVA分子结构对其改性沥青性能的影响

以秦皇岛AH-70沥青和克拉玛依AH-70沥青为基质沥青,以不同醋酸乙烯(VA)含量的乙烯-醋酸乙烯共聚物(EVA)为改性剂制备EVA改性沥青,采用动态力学分析(DMA)方法和荧光显微镜考察VA含量对EVA改性沥青流变性、相容性及常规性能等的影响。结果表明:在测定频率与温度范围内,随着VA含量的增加,EVA改性沥青的相位角δ增大,黏性成分逐渐增加,车辙因子G*/sin δ减小,抗车辙能力逐渐减弱,相容性先增强后减弱;在测定VA含量范围内,当VA含量为25％时,EVA改性沥青的综合性能达到最好;秦皇岛EVA改性沥青的抗车辙能力优于克拉玛依EVA改性沥青,克拉玛依EVA改性沥青的相容性相对较好。
Ethylene-vinyl acetate copolymer (EVA) modified asphalts were prepared by two base asphalts (AH-70 from Qinhuangdao and Karamay) and EVA modifiers with different vinyl acetate (VA) contents in the study. Influences of different VA contents on the rheological properties, compatibility and conventional properties of EVA modified asphalts were studied using dynamic mechanical analysis (DMA) and fluorescence microscopy. The results show that in the measured frequency and temperature region, phase angle and viscous part of EVA modified asphalts increase with the VA contents increasing, while the rutting factor G*/sin δ decreases indicating the anti-rutting ability declines. With the VA contents increase, the compatibility between of EVA and base asphalts presents the increasing trend firstly and then shows the decreasing trend. And the comprehensive properties of EVA modified asphalts are the best when the VA content is 25％. In general, the anti-rutting ability of Qinhuangdao EVA modified asphalts is better than that of Karamay. Nevertheless the compatibility of Karamay EVA modified asphalts is better than that of Qinhuangdao