高胶改性沥青超薄磨耗层路用性能研究

Research on Pavement Performances of High-rubber Modified Asphalt Ultra-thin Wearing Course

摘要:

为解决传统胶粉改性沥青存在的储存稳定性和性质不稳定等问题，使用一种新的高胶改性剂制备改性沥青，并通过增设6.7 mm筛孔来改良AC-10级配，形成了一种骨架密实型的ECA-10级配，通过车辙、马歇尔稳定度、低温弯曲等试验，对比验证了两种级配（ECA-10、AC-10）和三种沥青（SBS改性沥青、高黏沥青和高胶沥青）组合的沥青混合料路用性能，并通过微观形貌观测和红外光谱图来分析改性机理。结果表明：ECA-10级配的高温抗车辙性能优于AC-10级配，在采用高胶改性沥青后其高温性能进一步提高；高胶沥青混合料低温性能和水稳定性较其他类型沥青混合料有显著提升；高胶母粒在沥青中会溶胀形成不均匀的改性沥青体系，改性过程表现为物理共混改性的同时伴随化学反应。

Abstract:

In order to solve the problems of storage stability and property instability of traditional rubber powder modified asphalt, a new high-rubber modifier is used to prepare the modified asphalt, and through the addition of 6.7-mm sieve pore, the AC-10 gradation is modified to form a dense skeleton type of ECA-10 gradation. The rut test, Marshall stability test and low-temperature bending test are used to compare and verify the pavement performances of asphalt mixtures with two gradations (ECA-10 and AC-10) and three kinds of asphalt (SBS modified asphalt, high-viscosity asphalt and high-rubber asphalt). And the modification mechanism is analyzed by morphological observation and infrared spectroscopy. The results show that the high-temperature rutting resistance of ECA-10 gradation is better than that of AC-10 gradation, and its high-temperature performance is further improved after using the high-rubber modified asphalt. The low-temperature performance and water stability of the high-rubber modified asphalt mixture are improved more obviously than that of the other asphalt mixtures. The high-rubber masterbatch will swell in asphalt to form the non-uniform modified asphalt system of high-rubber asphalt. The modification process is characterized by physical blending and accompanying chemical reaction.