Research On Mechanical Behavior Occurring On Asphalt-aggregate Interface Subjected To Aging

Asphalt aggregate is extensively applied to road project,as its structural stability and durability are of profound significance to road project.As a matter of fact,its stability and durability are not constant since asphalt will undergo aging after long time of exposure to atmosphere and sunlight which will cut down on the lifespan of asphalt.Furthermore,aging will undermine adhesive property between asphalt and aggregate and cohesive property within asphalt itself.The two factors that are undermined will cause fissure and permanent deformation to road surface.In analyzing the influence of aging on interfacial mechanics of asphalt-aggregate,relevant experimental research is conducted including tests for basic properties of asphalts,shear experiments for asphalt-aggregate under the behavior of aging(148?,163?,178?,193? for 4 hours)and a comparison group,to research on influence of aging time and temperature on adhesiveness of asphalt-aggregate.Analysis includes four aspects.First of all,research is conducted towards interfacial mechanical performance of asphalt-aggregate under the action of aging and illustrates the values of physical meanings for the curves as well as their variation under the action of aging.Furthermore,a refined theoretical model is proposed based on experimental results by reference to a previously-proposed model.Results indicate that aging will undermine the interfacial mechanical performance.Otherwise the some values will then jump back as further aging intensify the solid property of asphalt.Secondly,adhesive and cohesive performance for asphalt-aggregate is analyzed under the influence of aging from the perspective of energy.In further analyzing the influence of aging on asphalt-aggregate,adhesive fracture energy and adhesive-cohesive composite fracture energy for double-peak curves are computed along with the comparison of fracture energy for first-peak partition under the condition of different aging.Analysis shows that the first two indicators undergo two stages as decrease and then increase.The third indicator decreases with aging instead.Thirdly,correlate the characteristics of healing property of asphalt material with the ratio change of single-peak and double-peak curves,and it can be concluded that the healing will recover the interfacial mechanical performance of asphalt to some degree during the shear process and then change the ratio of single-peak and double-peak curves.Fourthly,research alludes that interfacial slippage will occur during the process of shear failure forasphalt-aggregate.Shear displacement is the joint result of slippage and shear failure,which improve each other mutually.In addition,aging will make cohesive slippage transition into adhesive slippage.Moreover,the paper also conducts analysis over possible errors caused by experimental operations and their action mechanisms according to experimental approaches.