Study On The Adhesion Characteristics Of Asphalt-aggregate Interface Based On Pull-out Test

Asphalt pavement has been widely used in China,but due to various reasons,the early disease of asphalt pavement is very prominent,moisture damage is one of the common phenomena of early disease.Moisture damage is mainly caused by the asphalt membrane peeling off from the aggregate surface after moisture enters the asphalt mixture.Therefore,how to effectively evaluate the adhesion of asphalt and aggregate is an important aspect of the study of moisture damage of asphalt mixture.In this paper,drawing on the existing research results,based on the pull-out test,under different test conditions,according to different experimental materials,the pull-out test of asphalt aggregate interface is carried out,so as to analyze the influence of different material characteristics and aging and temperature in the service process on the adhesion of asphalt aggregate interface.In this paper,70# base asphalt,90# base asphalt and SBS modified asphalt are used as binders,and limestone ore powder or waste brake pad powder are used as fillers to prepare different asphalt pastes.Four kinds of materials,namely diabase,two kinds of limestone and waste brake pad,are used as aggregates to make the asphalt pastes adhere to the aggregates in a certain way,so as to obtain the required test Then pull-out tests are carried out under different conditions(aging and temperature),and the test data are analyzed.The results show that:(1)Different asphalts,aggregates and fillers have different effects on interface adhesion.Under the same asphalt,the difference between different types of natural stone materials is about 40% bigger than that under the same aggregate.Among them,the waste brake pad and modified asphalt have better adhesion;among the three kinds of asphalt,the adhesion effect of 90 × base asphalt is better than that of the other two kinds of asphalt for the same aggregate;the asphalt mortar with waste brake pad powder and rock aggregate have better adhesion effect In the range of powder binder ratio set in this paper,with the increase of powder binder ratio,the adhesion effect is also improved.(2)Aging can significantly affect the adhesion of asphalt binder to aggregate.Shortterm aging will enhance the adhesion between the base asphalt and the waste brake pads,but the adhesion between the aged asphalt mortar and the aggregate will become worse.When limestone A is used as the aggregate,the opposite result will be obtained.The effect of longterm aging on 70# asphalt matrix and SBS modified asphalt is the opposite.Long-term aging will enhance the adhesion performance of 70# asphalt binder,while SBS modified asphalt binder is the opposite.(3)The process of asphalt aggregate interface failure is obviously affected by temperature.With the increase of temperature,the peak load of interface failure decreases,and the interface failure energy decreases;at lower temperature,the interface mainly occurs the cohesive failure,while at higher temperature,the interface mainly occurs the cohesive failure of cementitious materials.As for the damage of asphalt aggregate interface,compared with the temperature sensitivity of three kinds of asphalt,70# asphalt is the strongest and SBS modified asphalt is the weakest.Under the condition of short-term aging,the temperature sensitivity of 70 # pure asphalt adhesive performance will be affected,while the asphalt binder under the condition of aging will not be affected under other circumstances.