以布氏旋转黏度为指标,研究了废旧胶粉掺量、粒径、制备工艺等特性对橡胶沥青以及滤除胶粉后改性沥青黏度的影响,并采用凝胶色谱试验分析了沥青大分子(LMS)的变化,在此基础上,探讨了胶粉与沥青的反应作用(IE)与胶粉颗粒在沥青中的交联作用(PE)对橡胶沥青黏度的影响机理。研究结果表明:随着胶粉掺量的增加,橡胶沥青的黏度、胶粉与沥青的反应作用及未反应胶粉的交联作用、LMS含量也逐渐增大,滤除未反应胶粉颗粒后的改性沥青黏度增长并不明显;常温胶粉改性沥青的黏度、胶粉与沥青的反应作用和未反应胶粉的交联作用明显高于冷冻胶粉改性沥青的黏度,而80目或高掺量冷冻胶粉改性沥青过滤沥青的黏度大于常温胶粉改性沥青过滤沥青的黏度,不同生产工艺胶粉改性沥青的LMS含量没有明显变化规律;40目的废旧胶粉改性沥青的黏度和未反应胶粉的交联作用较30目和80目大,而80目常温胶粉改性沥青中胶粉与沥青的反应作用最大,增加冷冻胶粉的细度对于增加滤除未反应胶粉颗粒后改性沥青的黏度更有效,胶粉粒径越小,橡胶沥青LMS含量越大;橡胶沥青的LMS与黏度有较为显著的相关性,与其IE有一定的相关性,而与PE的相关性较差。废旧胶粉特性对橡胶沥青的黏度影响显著,合理地选择废旧胶粉参数有助于制备高性能的橡胶沥青。
Effect of crumb rubber modifier (CRM) characteristics on rubber asphalt and rubber asphalt binder filtered rubber powder was studied based on Brookfield viscosity. Thesecharacteristics include content, particle size and production method. Large molecular sizes (LMS) of asphalt were analyzed by high pressure-gel permeation chromatographic experiment. Based on this, the influence mechanism of the interaction effect (IE) and the particle effect (PE) on Brookfield viscosity was discussed. The results show that the viscosity, IE, PE and LMS increase as the crumb rubber content increase for rubber asphalt binder, which is not obvious for asphalt binder filtered rubber particle size. The viscosity, IE, PE of ambient rubber asphalt binder are obviously larger than that of cryogenic CRM binders. The viscosity of cryogenic asphalt binder filtered rubber particle size is larger than that of ambient asphalt binder filtered rubber particle size when particle size is 80 mesh or high content. The LMS change rule is not obvious for ambient and cryogenic rubber asphalt binders. The viscosity and PE of 40 mesh rubber asphalt are larger than that of 30 and 80 mesh asphalt, and the IE of 80 mesh rubber asphalt is the highest. It is more effective to reduce particle size for the viscosity of cryogenic asphalt binder filtered rubber particle size. The smaller the particle size of rubber, the larger the LMS of rubber asphalt. LMS has a significant correlation with viscosity and certain relevance with IE, but it is poor for PE. There is a significant influence of crumb rubber modifier characteristics on rubber asphalt binder. Reasonable rubber characteristic is helpful to produce high efficiency rubber asphalt binder. 5 tabs, 11 figs, 30 refs.