活化废胶粉改性沥青机理研究

Research on the Mechanism of ACRM

针对微波辐射活化废胶粉改善沥青的作用机理展开了研究。采用微波辐射的方法对胶粉进行活化,实验室制备普通废胶粉改性沥青与活化废胶粉改性沥青。利用接触角分析、溶胀试验及X射线能谱分析(EDS)等方法研究了微波活化胶粉的机理;利用电子扫描显微镜(SEM)、差示扫描热量仪(DSC)及动态热机械分析仪(DMA)分析了活化胶粉改善沥青性能的机理。结果表明:活化后废胶粉表面接触角、平衡溶胀率、表面羟基含量、含氧基团均增加,微波辐射有效地打断胶粉中的S-C和S-S键,胶粉从原本交联的网状结构转变为线形结构,使得胶粉表面活性大大加强;活化胶粉在沥青中的颗粒形貌更加蓬松,体积膨胀更加明显,与沥青结合更加稳定,活化胶粉改性沥青的结构更加均匀和致密;沥青组分及其损耗角正切发生变化,因而其性能更优越。

The mechanism of activated crumb rubber modified asphalt （ACRM） was carried out. Microwave radiation was adopted to activate the crumb rubber powder, the ordinary crumb rubber modified asphalt （CRM） and ACRM were made in laboratory. Surface contact angle analysis, swelling experiment, X-ray energy dispersion spectroscopy were adopted to study the activation mechanism of microwave radiation to crumb rubber powder. SEM, DSC and DMA were adopted to analyze the performance improvement mechanism of the activated crumb rubber to the modified asphalt. The results show that （1） the contact angle, the average ratio of swelling, the surface hydroxyl and the oxy group of the activated crumb rubber （ACR） are all raised; （2） microwave radiation is effective to break the bonds of S-C and S-S of the crumb rubber （CR） resulting in the part network structures of the CR transform into line structure whose surface activation is superior; （3） the ACR becomes softer and bigger when it is mixed with asphalt, the interface bonding between CR and asphalt is tighter, the structure of ACR modified asphalt is more uniform and compact; the chemical component and the loss tangent of CRM and ACRM are changed. All of the above greatly improved the performance of modified asphalt.