Experimental Study On Different Surface Treatment Technologies Of Semi-rigid Asphalt Pavement Interlayer

Although semi-rigid asphalt pavement has been widely used in our country,the problems of poor interfacial bonding and low strength have not been solved at all.The quality of layer interfaces is one of the important factors that affect the service life of asphalt pavement.If the interlayer bonding is not good,the integrity of the pavement structure is easily damaged,which weakens the overall strength of the pavement structure.In order to study the strengthening law of the interlayer between asphalt pavement and semi-rigid by different treatment methods,the semi-rigid asphalt pavement is used as the research object.This paper introduces the strength theory of the interlayer interface.The shear strength and tensile strength of the interlayer interface are evaluated through direct shear and drawing test,and the different treatment methods have been carried out.The details of the research can be described as follows.Firstly,studying the interfacial bonding properties at different temperature gradient pretreatments at the base level,the influence of different temperature on the bonding strength of interlayer interface is discussed.And the best preheating temperature of the base surface is found out.Secondly,through picking the surface of the base,explores the influence of friction on the interlaminar strength.Nextly,the influence of increasing the unit cohesive force on the interlayer strengthening is explored by the groove treatment on the base surface.Finally,the influence of strengthening the macroscopical mechanical properties and increasing the microstructure on the interlaminar strength is discussed by the influence of different shapes on the surface of the base.The research results indicate that: for the base surface preheating treatment,the base surface strength can be increased by increasing the preheating temperature of the base surface in a certain range due to the permeability of the bitumen and the permeability of the asphalt,and compared with the base surface preheating at 50?,the interlayer shear strength increased by 59.01% and the interlayer tensile strength increased by 34.16% when the base surface was preheated at 90?,and the base surface preheating was 110?;for the surface grooving treatment of the base surface,the effective bonding area between the base layer is increased and the bonding stress unit of the interface is increased accordingly,thus the bonding strength between the base layer is enhanced.When the groove spacing is reduced from 20 mm to 8mm,the shear strength of the interlayer increases by 27.02%,and the tensile strength increases by 27.81%;the treatment of different shapes at the base level can increase the physical relay force between the base planes in a certain range,so as to improve the interlaminar strength.When the height of semicircular pits increased from 6mm to 17.5mm,the shear strength increased by 58.47%,and the tensile strength increased by 47.88%;improving the roughness of the base surface can improve the friction and cohesive force between the base planes,thus improving the interface strength between the base planes,and compared with the untreated surface,the shear strength of the interlayer interface is increased by 27.41%,and the tensile strength is increased by 18.83%.