Research On The Interlayer Of Ltrathin Asphalt Pavement Shear Strength

In recent years,our country has launched a large number of ultra-thin asphalt concrete overlay project,in order to extend the life of asphalt concrete pavement and improve the performance of pavement.Although there has been a lot of research on the paving asphalt overlay,it has not been able to form a complete design theory and construction technology.A lot of asphalt pavement appear a variety of shear failure soon after the overlay,such as rutting,slippage failure,upheaval,especially much attention has been paid to the interlaminar shearing fracture of asphalt pavement.Because the require of bonding layer in current standard and specification is relatively single.Therefore,how to improve the bonding properties of asphalt pavement layer is necessary for further study.In this paper,based on the study of the influence factors of shear strength for Ultra-thin asphalt pavement,through the comparative analysis of the influencing factors,to find effective measures to improve the shear strength of asphalt pavement.To cooperate with the study,the paper has done a lot of improved test related indicators of matrix asphalt with High elastic and high viscosity polymer,the effect is obvious.In order to reduce the influence of other factors on the experimental results,the raw materials used in this paper were selected,especially Xuan Wuyan.Different types of asphalt mixture,which are involved in the experiment of the paper,are designed in detail according to the requirement of the specification,include AC-13,SMA-10,Type-B,OGFC-10.According to the literature review of related studies in China and abroad,this paper takes the direct shear test between layers as the basic research method,to calculate the maximum shear modulus between the layers as the evaluation index of the shear strength of the asphalt pavement.The influencing factors of this paper include the test temperature,the amount of the adhesive layer,the gradation of asphalt mixture,the asphalt binder,the thickness of the surface layer.Experimental results show that the effect of the experimental temperature on the shear strength of asphalt pavement is the most prominent.With the increase of the test temperature,Interlayer Shear Strength and Maximum Shear Modulus decreases,and the max Interlayer Shear Strength at 60? is only about 1/10 at 20?.In addition,there is a close relationship between the gradation of asphalt mixture,the asphalt binder,the amount of the oil layer and the shear strength of the layers.The influence of different mixture level on the bonding properties of the layers is SMA-10 > Type-B > OGFC-10;The shear strength of different asphalt binders is 1# high viscosity asphalt binder > 2# high viscosity asphalt binder > asphalt binder C;The SBS modified emulsified asphalt is used as a layer of adhesive layer oil,and the optimum dosage of the adhesive layer is corresponding to the different working conditions,and not the amount of bonding performance is better.Under the experimental conditions,the thickness of asphalt pavement has no obvious influence on the bonding performance between layers.