改性沥青混合料路用性能的对比研究

Comparative study on application performance of modified asphalt mixture for road pavement

为了研究掺加不同改性剂高模量沥青混合料作为基层材料的路用性能,解决沥青混凝土路面的流动性车辙问题,文章以AC-25C级配沥青混合料为研究对象,对70#普通沥青混合料以及掺加SBS、RA和PR.M改性剂的沥青混合料进行车辙试验和SPT动态蠕变模量等试验,改性剂的掺加量均为0.7%。结果表明,掺加改性剂后的沥青混合料路用性能较普通沥青混合料有显著提高;因沥青混合料多数情况下承受的是动态荷载,故通过对比动态模量的结果可知,55℃时掺加RA改性剂沥青混合料的动态模量明显高于掺加PR.M改性剂的沥青混合料。因此提出掺加RA改性剂的高模量沥青混合料作为基层的全厚式高模量沥青混凝土路面,将有效解决沥青混凝土路面的流动性车辙问题。研究成果对改善全厚式高模量沥青混凝土路面的车辙问题具有指导意义或参考价值。

AC-25 C asphalt mixture is taken as the study object herein,so as to study the performance of the high modulus asphalt mixture mixed with various modifiers used for the substrate material of road pavement and solve the problem of flow rutting on asphalt concrete road pavement,and then rutting experiment,SPT dynamic creep modulus test,etc. are made on the No. 70 ordinary asphalt mixture and the asphalt mixtures mixed with SBS,RA and PR. M modifiers,for which all the admixing amounts of the modifiers are 0. 7%. The result shows that compared with the ordinary asphalt mixture,the performances of the asphalt mixture mixed with the modifiers used for road pavement are significantly enhanced. As the asphalt mixture is subjected to dynamic loads in most cases,it can be known through the result of comparing with dynamic modulus that the dynamic modulus of the asphalt mixture mixed with RA modifier is obviously higher than that mixed with PR. M modifier at 55 ℃. Therefore,it is proposed that taking the high modulus asphalt mixture mixed with RA modifier as the substrate material for the full depth high modulus asphalt road pavement can effectively solve the problem of flow rutting on asphalt concrete road pavement. The study result has referential value for improving the problem of the rutting on the full depth high modulus asphalt road pavement.