基于表面自由能的再生沥青粘附性及其水稳定性

Adhesion and Water Stability of Regenerated Asphalt Based on Surface Free Energy

为探究不同种类的再生剂对沥青-集料界面体系的粘附性和水稳定性的影响,采用躺滴法分别测试了原样、老化及以不同掺量再生剂A、B和C制得的再生沥青与测试液体之间的接触角,基于表面自由能理论分别计算了沥青-集料界面体系的粘附功和沥青-集料-水体系的剥落功。结果表明:沥青的老化导致其表面自由能减小,削弱了沥青与集料界面之间的粘附性,加速了浸水条件下沥青的剥落;相比老化沥青,再生沥青的表面自由能和粘附功均增大,抗水剥落能力增强。以能量参数ER作为综合评价沥青-集料界面体系的水稳定性指标,随着再生剂的掺入,沥青-集料界面粘附功及沥青之间的粘聚功均增大,剥落功的绝对值减小,ER值增大,沥青-集料界面体系的抗水损害能力提高;相同掺量下三种再生剂对再生沥青-集料界面体系的水稳定性改善效果由强至弱顺序为B>C>A。

In order to explore the influence of different rejuvenators on the adhesion and water stability of asphalt-aggregate interface system,the contact angles between different asphalt with three kinds of test liquids were detected by the sessile drop method.The adhesion and spalling work were calculated based on the surface free energy theory.The results show that compared with the virgin asphalt,the surface free energy and adhesion work of aged asphalt reduce,and it is easy to be replaced by water and peeling.Compared with the aged asphalt,the free energy and the adhesion work of the regenerated asphalt are increased,and the ability to resist water spalling is enhanced.The energy parameter ER is used to evaluate the water stability index of the asphalt-aggregate interface system.The absolute value of the spalling work decreases and the ER value increases with the addition of rejuvenators,which makes the water damage resistance of the interface system of asphalt and aggregate improve.The effect of three rejuvenators on the water stability of regenerated asphalt-aggregate interface system is from strong to weak at B>C>A.