粒化聚合物抗车辙剂对沥和沥青混合料的改性机理

摘要

Granulated polymer anti-rutting additive PLAST.S could improve performances of asphalt and asphalt mixtures.In order to analyze the modification mechanism,main technical indexes of different PLAST.S modified base asphalts were firstly studied compared with corresponding base asphalt processed by the same technology.Then road performances of PLAST.S modified asphalt mixtures by dry process and wet process were analyzed.At last,combined with the physical form of PLAST.S both in asphalt and asphalt mixture,also with the improving effect of PLAST.S on asphalt and asphalt mixture,modification mechanism of PLAST.S was analyzed.The research results show that penetration and ductility of PLAST.S modified asphalt decrease,whereas softening point of PLAST.S modified asphalt increases,and this variation trend becomes more evident with heating and mixing time increasing.Adding PLAST.S into asphalt mixture can improve high temperature performance and water stability while it has little effect on crack resistance at low temperature.PLAST.S mainly plays the role of physical modification for asphalt and asphalt mixtures.The physical form of PLAST.S is changed at high temperature,and performances of asphalt mixture are improved by reinforcement,void-filling,constraint effect and so forth after cooling.Properties of asphalt are improved by thickening effect.%粒化聚合物抗车辙剂PLAST.S可以改善沥青及沥青混合料的性能,为了研究PLAST.S的改性机理,首先研究了PLAST.S改性不同基质沥青的主要技术指标,并与相同加工工艺下相应基质沥青的技术指标进行对比;然后采用干法和湿法工艺,分析了PLAST.S改性沥青混合料的路用性能;最后结合PLAST.S溶于沥青和成型沥青混合料时的物理形态,以及PLAST.S对沥青及沥青混合料性能的改善效果,分析了PLAST.S的改性机理.研究结果表明:在沥青中添加PLAST.S后,可以减小沥青的针入度,增大沥青的软化点,但是沥青的延度也随之减小,并且随着加热搅拌时间的延长,变化幅度相对增大;PLAST.S可以显著提高沥青混合料的高温稳定性与水稳定性,但对沥青混合料低温抗裂性能无显著改善;PLAST.S对沥青及沥青混合料主要起物理改性作用,高温下PLAST.S物理形态发生变化,冷却后通过增稠或加筋、填隙、牵制等作用分别改善沥青或沥青混合料的性能.