Research On Interlayer Processing Technology Of Composite Pavement Base Based On Bionic Pit Structure

The rigid-flexible composite pavement structure has been applied on a large scale in the design and construction of high-grade highways in China.However,the interlaminar damage caused by the insufficient interface strength between the base layers is one of the key technologies which still needed to be solved in the design and construction of long-life pavement.In this paper,the advantages and disadvantages of the common diseases between the base layer and the traditional basal layer treatment methods are analyzed.Combined with the structure bionics theory,the inter-layer treatment method based on the bionic structure of the base surface pit is proposed.Based on the analysis and experimental methods,the influencing factors of the interlaminar shear stress based on the method are analyzed.Firstly,the parametric design logic of bionic structure on the surface of composite pavement is proposed by the analysis of biomimetic structural unit extraction and characterization and friction mechanism of bionic structure.Based on this,a series of parametric models for analysis are constructed.Secondly,based on the parametric model,the influence of the bionic structure parameter combination on the interlaminar shear stress is discussed by ABAQUS finite element software.The optimal pit biomimetic structure parameters are obtained.Then,based on the optimal combination of bionic structure parameters,the influences of load type and size on the interlaminar shear stress of composite members based on bionic layering of pits on the base surface are analyzed.Finally,the inter-layer shear strength of composite members under three different interlayer treatment modes including the bionic structure of the base surface and other three different interlayer treatment methods was compared by using the indoor shear test.The feasibility and effectiveness of the proposed interlayer treatment method were verified.The simulation analysis shows that the optimal parameter combination based on the bionic structure of the base surface pit is pit depth: 0.013 m,pit diameter: 0.017 m,pit pitch: 0.005m;As the vertical load/horizontal load increases,the vertical and radial maximum shear stresses between the layers increase with different proportions,and the bond strength between the base layers is sensitive to horizontal loads.The experimental results show that the interlaminar shear strength of composite members based on the bionic structure of the base pits decreases with the increase of temperature,and increases with the increase of shear rate,which is based on the bionic structure of the base pit.The composite member under the interlayer treatment mode has high high-temperature shear resistance and has a good slowing effect on interlaminar shear deformation caused by excessive shear rate.