复合改性硬质沥青的制备及微观结构

摘要

以秦皇岛AH-70为基质沥青,外掺改性胶粉、SBS和硬沥青制备复合改性硬质沥青,考察制备方法(四步剪切法和三步剪切法)、剪切时间及外掺剂对其性能的影响,对制备过程中的微观相态进行研究。结果表明：四步剪切法所制备的复合改性硬质沥青性能优于三步剪切法,每步较合适的剪切时间为60、60、30和20 min,在此工艺条件下,胶粉、SBS和硬沥青的掺量分别为20%、2%、20%,所制备的复合改性硬质沥青的性能均满足浇注式沥青的指标要求；复合改性硬质沥青的制备是一个复杂的物理化学过程,既存在物理共混又发生化学反应,同时制备过程中其相态结构发生转变,由沥青为连续相、SBS为分散相,转变为沥青和SBS为双连续相,最后又转变为沥青连续相、SBS分散相。%COmpOsite mOdified hard asphalt was prepared by adding crumb rubber, SBS and hard asphalt tO QinhuangdaO AH-70 base asphalt. The influences Of preparatiOn methOds ( fOur-step and three-step shearing methOd) , shear time, as well as the additives On the perfOrmance Of cOmpOsite mOdified hard asphalt were investigated. And the micrOscOpic phase Of cOmpOs-ite mOdified hard asphalt during preparatiOn using fOur-step methOd was characterized. The results shOw that the perfOrmance Of cOmpOsite mOdified hard asphalt prOduced by fOur-step shearing methOd is better than that prOduced by three-step shearing methOd, in which the Optimal shear time are 60 min, 60 min, 30 min and 20 min, respectively. Under abOve cOnditiOns, the key perfOrmance Of cOmpOsite mOdified hard asphalt meets the gussasphalt standard when the cOntents Of crumb rubber, SBS and hard asphalt are 20%, 2%, and 20%, respectively. PreparatiOn Of cOmpOsite mOdified hard asphalt is a cOmplex physi-cal and chemical prOcess. And it is fOund that phase mOrphOlOgy is cOnverted frOm a cOntinuOus asphalt phase tO bicOntinuOus phase, and then a cOntinuOus asphalt phase again.