硅烷偶联剂对复合沥青混合料路用性能的影响

针对胶浆与集料界面粘附对沥青混合料性能的影响，采用“三步”成型工艺制备复合沥青混合料试件，研究了KH-550硅烷偶联剂对其路用性能的影响，并借助IR和SEM等微观设备，分析了硅烷偶联剂在复合沥青混合料中的偶联机理。结果表明，随硅烷偶联剂用量增加，复合沥青混合料在7d和28d龄期的路用性能先提高后降低，当用量为乳化沥青质量分数的0．6％时，混合料冻融劈裂强度比、马歇尔稳定度和抗压回弹模量等路用性能提高了10％～30％。硅烷偶联剂改性后的花岗岩集料引入了偶联剂分子结构的Si-O键，在胶浆与集料界面有Si-O-Si键的生成；掺加偶联剂后的水泥乳化沥青胶浆表面变得凹凸不平，结构致密性提高；水泥乳化沥青胶浆能够较好地粘附于花岗岩集料表面，胶浆与集料界面结构得到改善。

Effects of Silane Coupling Agent on Road Performances of Composite Asphalt Mixtures

Aiming at the influence of mastics to aggregate adhesion on the performances of asphalt mixtures, three modeling techniques were adopted to prepare composite asphalt mixtures specimens. The influences of silane coupling agent on their road performances were studied and coupling mechanism was analyzed with Infrared Spectroscopy （IR） and Scanning Electron Microscope （SEM）. The results indicated that the road performances at 7-day and 28-day curing age increased in the beginning and then decreased with the increase of silane coupling agent dosages. The road performances, such as freeze-thaw splitting strength ratio, Marshall stability and compression modulus would be enhanced 10%-30% at 0. 6% in asphalt emulsion mass. There was Si O-Si chemical bond on interface between mastics and modified granite aggregate by Si-O chemical bond of silane coupling agent. Surface of cement asphalt emulsion mastics was rough and its structure was dense. The cement asphalt emulsion mastics can be adhered to granite aggregate surface and mastics to aggregate interface structure is improved with silane coupling agent addition.