老化对不同沥青与集料黏附性的影响研究

Study on the Effect of Aging on the Adhesion between Different Asphalts and Aggregates

老化使沥青路面易出现龟裂、松散等病害,影响路面行驶质量。采用水浸+图像处理、接触角试验、冻融劈裂试验等方法,从宏观和微观界面角度,研究老化对沥青性能及与集料界面黏附性的影响。结果表明,老化使沥青的黏度增大,内聚力增大,表面自由能增大,极性和活性降低;老化使沥青与集料间的黏附功减小,剥落功增大,使沥青与集料之间黏附性降低;随着老化程度的加深,SBS改性沥青混合料试件冻融劈裂强度比衰减值小于70号沥青,其与集料的黏附性优于70号沥青,抗老化能力优于70号沥青;定量化的裹覆率、黏附功、剥落功等指标,表征黏附性与冻融劈裂强度比具有一致性。

Aging is one of the most important factors that make asphalt pavement prone to crack,looseness and other diseases,which affects the quality of pavement.In this paper,multiple measurements including water immersion,image processing,contact angle test,and freeze-thaw splitting test were used to study the influence of aging on asphalt performance and interfacial adhesion of aggregate from the perspective of macro and micro interface.Results show that aging increases the viscosity,cohesion,surface free energy,but decreases the polarity and activity of asphalt,leading to such a phenomenon that aging would reduce the adhesion between asphalt and aggregate.It could be also found that with the deepen of aging,the attenuation value of freeze-thaw splitting strength of SBS modified asphalt mixture is less than that of 70#asphalt,indicating that the SBS asphalt represents better aging resistance than 70#asphalt.Quantitative indexes such as coating rate,adhesion work and peeling work could be used to evaluate the water stability of asphalt mixture.