制备废胶粉改性沥青是实现废橡胶资源化利用及减轻环境污染的有效途径． 为了研究胶粉在沥青中的物化行为以及对沥青的改性作用，分别在不同胶粉掺量、不同温度
和处理时间条件下制备胶粉改性沥青，采用洗脱法分离胶粉后，使用光学显微镜测定胶粉粒径的变化，提出体积膨胀率表征胶粉在沥青中的体积变化;并对用筛析方法分离胶粉后的沥青样品，进行了红外光谱(IＲ)和差示扫描量热(DSC)分析． 结果表明:制备胶粉改性沥青过程中，溶胀和降解是影响胶粉体积的两个重要因素，随着胶粉掺量增加、制备温度升高和处理时间延长，体积膨胀率均呈先增大后减小趋势;溶胀后的橡胶分子发生断链降解释放出小分子物质溶于沥青组分发挥改性作用，特征官能团吸收峰大幅增强;195 ℃，1． 5h 和 175℃，3． 0h 制备的沥青样品 DSC 谱线出现了强烈的吸热峰，即处理温度过高或时间过长，可能发生胶粉过度降解、胶粉团聚或沥青老化行为，使胶粉改性沥青的物化状态发生改变，导致性能劣化． 从胶粉溶胀与降解的角度，建议胶粉掺量在 20% 左右，处理温度不高于 195℃，处理时间不超过 1． 5h．

To prepare the crumb rubber-modified asphalt (CRMA) is an effective way to recycle waste rubber and reduce environmental pollution.In order to investigate the physical and chemical behaviors of the crumb rubber in asphalt and its modification on asphalt,CRMAs were prepared respectively under the conditions of different powder dosages,temperatures and treatment time.Then,the particle size of the crumb rubber,which had been separated from asphalt by means of the elution method,was measured by using an optical microscope,and the volume expan- sion rate was proposed to characterize the volume change of the crumb rubber in asphalt.Besides,the IR and DSC tests were conducted on the asphalt samples in which the crumb rubber had been removed by means of the sieve method.The results indicate that (1) swelling and degradation are the two important factors influencing the volume of the crumb rubber in the process of preparing CRMAs,and the volume expansion rate first increases and then de- creases with the increases of the crumb rubber dosage and the preparation temperature as well as the extension of the treatment time; (2) after the swelling,the molecular chains of the rubber rupture and release small molecule materials,and the materials dissolve into asphalt and play a role of asphalt modification,which causes the absorp- tion peaks of typical functional groups to significantly increase; and (3) strong endothermic peaks appear in the DSC curves of the asphalt samples prepared under the conditions of 195℃,1. 5h and 175℃,3. 0h,which means that such processing conditions as too high temperature and too long time may lead to the excessive degradation or aggregation of the crumb rubber as well as the asphalt aging,thus changing the physical and chemical states of the CRMAs and degrading their performances.From the perspective of the swelling and degradation of the crumb ru- bber,it is suggested that the crumb rubber dosage and the processing time should respectively be 20% approxi- mately and less than 1. 5h,and that the preparation temperature should not be higher than 195℃.