Influence Factors Of Bonding Properties Between Asphalt Pavement Layers

The Technical Specifications for Construction of Highway Asphalt Pavements specifiedthat used layer-elastic theory on the basis of mechanics-empirical method for pavementstructure designing and calculation. Layer-elastic theory assumes that the interlayer is incontinuous state. It is difficult to achieve fully continuous state actually so that the actualbottom tensile stress of pavement layer is larger than designing value. And the problems ofpavements appear easily and early, usability reduced, and the service life affected. Therefore,it makes corresponding technical measures to ensure the layers bonding together and ensurethe service life of pavement. Using tack coat between the layers is the measure to strengthenthe interlayer bonding effect and shear strength. Existing research about adhesive property oftack coat shows that, most direct shear tests are not containing vertical load and it is differentwith the actual stress. So it is necessary to research the influence factors of bonding propertiesusing tester which close to road actual stress.Based on the existing research, the paper research the influence of temperature, load,emulsified asphalt, stress absorbing layer and pollution by using a multi-function interlayerstress tester which close to road actual stress.The results show that the best application rates is0.8kg/m2at the conditions of25℃,45℃and65℃and the shear strength is gradually decreased as the temperature rises. Theincreasing of vertical load lead to the increasing of shear strength and large load lead to thereduce the influence of application rates on the bonding properties. The shear strength orderof pavement structure is AC-13>AC-16>SMA>OGFC. Both of the pollutions reduce theshear strength of asphalt pavement and the oil pollution has greatest impact. The SBSmodified asphalt emulsion provide the maximum shear strength.