基于表面能理论的改性沥青-集料界面黏结性

Adhesion of Modified Asphalt-Aggregate Interface based on Surface Energy Theory

为系统探究沥青特性、集料岩性及老化条件对沥青-集料界面黏结性的影响,选取SK-70号基质沥青、胶粉改性沥青、SBS改性沥青(两种掺量)、高黏改性沥青共5种沥青,选用石灰岩、玄武岩2种集料,测量各沥青与集料的表面能参数,计算得到各体系黏附功、剥落功及能量比ER值,分析得到沥青-集料黏结性规律。结果表明:5种沥青在干燥条件下与石灰岩之间的界面黏附功均要大于玄武岩,且集料种类对黏附功的影响要大于沥青种类的影响。改性剂的加入可以提高沥青-集料的界面黏附性与抗水损坏性能,且SBS改性沥青、高黏改性沥青与集料的黏附性最优,胶粉改性沥青与集料的黏附性次之。老化效应降低了沥青与集料的黏附功和ER值,削弱了沥青-集料界面的抗水损害性能;高掺量SBS改性沥青由于聚合物的部分降解使其浸润性得到一定恢复,较普通改性沥青(胶粉与高黏剂)表现出更好的黏附性。

In order to systematically explore the influence of asphalt characteristics,aggregate lithology and aging conditions on the cohesiveness of asphalt-aggregate interface,in this paper the SK-70号matrix asphalt,rubber powder modified asphalt,SBS modified asphalt(two kinds of mixing)and highly viscous modified asphalt are chosen,and limestone and basalt aggregates are selected to measure the surface energy parameters of each asphalt and aggregate.The adhesion work,spalling work and energy ratio ER values of each system are calculated,and the law of asphalt aggregate adhesion is obtained.The results show that the interface adhesion work of five kinds of asphalt with limestone is greater than that of basalt under dry conditions,and the influence of aggregate type on adhesion work is greater than that of asphalt type.The addition of modifiers can improve the interface adhesion and water damage resistance of asphalt and aggregate,and the adhesion of SBS modified asphalt and high viscosity modified asphalt to aggregate is the best,followed by the adhesion of rubber powder modified asphalt to aggregate.The aging effect reduces the adhesion work and ER value of asphalt and aggregate,and weakens the water damage resistance of the asphalt-aggregate interface.The high content SBS modified asphalt has a certain recovery of its wettability due to the partial degradation of polymer,showing better adhesion than ordinary modified asphalt(adhesive powder and high viscosity agent).