Abstract: In order to study the influence rule and the action mechanism of adding silane coupling agent on the performance of semi-flexible pavement materials, Marshall stability test, rutting test, low temperature bending test, freeze-thaw splitting test and other tests were adopted to test the mechanical properties and road performance of semi-flexible pavement materials with different dosage of silane coupling agents. And the optimal dosage of silane coupling agent was also determined. The micro-modification mechanism of silane coupling agent based on the interface modification principle was observed by instruments such as a high magnification instrument. The results show that with the increase of the dosage of silane coupling agent, the high temperature performance, low temperature performance and water stability of the semi-flexible pavement have all been improved to varying degrees. At the same time, there is a peak effect of its dosage on performance. The Marshall stability, dynamic stability, bending tensile strain, and freeze-thaw splitting strength ratio all reach their peak at around 0.5%. After exceeding the peak, the performance decreases with the increase of the dosage. Finally, the optimal dosage of silane coupling agent is determined to be 0.5%. The interface tightness is quantitatively reflected by measuring the changes in connectivity porosity and perfusion rate. Combined with observation and comparison, it can be clearly observed that silane coupling agents can react between cement-based grouting materials and asphalt mixtures through a series of chemical reactions, thereby altering the morphology of the cement-asphalt interface, by comparing the cement asphalt interface of the semi-flexible pavement material under the optimal dosage of silane coupling agent and that of the ordinary semi-flexible pavement material. The stability of cement-asphalt interface is effectively improved and the cracks at the cement asphalt interface are reduced. Combined with performance tests, silane coupling agents can improve the mechanical and road performance of semi-flexible pavement through interface optimization.

Key words: highway engineering; semi-flexible pavement materials; interface optimization; silane coupling agent; road performance; pouring semi-flexible pavement matrix asphalt mixture

摘要： 为研究掺加硅烷偶联剂对半柔性路面材料的性能影响规律及作用机理，采用马歇尔稳定度、车辙、低温弯曲、冻融劈裂等试验，测试了添加不同掺量硅烷偶联剂的半柔性路面材料的力学性能与路用性能，并确定硅烷偶联剂的最佳掺量，采用高拍仪等仪器观察硅烷偶联剂基于界面改性原理的微观改性机理。结果表明：随着硅烷偶联剂掺量的增加，半柔性路面的高温性能、低温性能和水稳定性能均发生了不同程度的提高，同时其掺量对性能的影响存在峰值，马歇尔稳定度、动稳定度、弯拉应变与冻融劈裂强度比均在掺量为0.5%左右处达到峰值，超过峰值后性能随掺量增加而下降，最终确定硅烷偶联剂的最佳掺量为0.5%。通过测定连通空隙率和灌注率的变化定量反映界面紧密度，通过对比观察普通半柔性路面材料与硅烷偶联剂最佳掺量下的半柔性路面材料的水泥-沥青界面可明显发现，硅烷偶联剂能够在水泥基灌浆材料与沥青混合料之间发生一系列化学反应，从而通过改变水泥-沥青界面的形态，有效改善水泥-沥青界面稳定度并减少水泥-沥青界面裂缝，结合性能试验，硅烷偶联剂可通过界面优化改善半柔性路面的力学及路用性能。

关键词: 道路工程；半柔性路面材料；界面优化；硅烷偶联剂；路用性能；灌注式半柔性路面基体沥青混合料