| In recent years,with the rapid growth of air traffic and the proportion of large wide-body aircraft,the pavement structure of some early-built airport runways（such as Xinzheng Airport）has been seriously damaged,and the service performance has plummeted.In order to solve the problem of damage to the old pavement,the service life of the pavement can be extended by overlaying,and the interlayer bonding material between the old pavement and the overlay has also become the focus of research.This paper firstly takes the interlayer adhesive layer material as the research object,and independently developed a kind of adhesive layer material SBS（Styrenic Block Copolymers）-SBR（Polymerized Styrene Butadiene Rubber）to improve the bonding performance.For the composite modified emulsified asphalt,the performance of the material is analyzed through relevant laboratory tests;then the finite element software is used to simulate the contact between the layers,and the stress state between the pavement layers is analyzed.The main research conclusions are summarized as follows:（1）Based on the orthogonal experimental design method,the influence factors such as modifier content and emulsifier content of composite modified emulsified asphalt were studied;and through conventional physical property tests,seven kinds of modified emulsified asphalt were compared Physical properties,and then according to the results of the range analysis:the influence of modifier and emulsifier on the composite modified emulsified asphalt is ranked as SBS modifier>emulsifier>SBR modifier,and the composite modified emulsified asphalt is preferred.The content of modifier and emulsifier is 1.5%SBS+3.0%SBR+1.0%emulsifier.（2）Based on the principle of rheology,the viscoelastic properties and high temperature stability of composite modified emulsified asphalt were studied by dynamic shear rheometer,and the rheological properties under different strains,temperatures and frequencies were obtained,and multi-stress creep recovery analysis was carried out.The results showed that compared with matrix emulsified asphalt and modified emulsified asphalt,the selected composite modified emulsified asphalt had better high temperature stability and deformation resistance.Then,with the help of fluorescence microscope and thermogravimetric analyzer,the microscopic mechanism changes of the composite modified emulsified asphalt were explored.The results showed that the emulsified asphalt formed a relatively stable network structure after being combined with SBS and SBR modifiers.Asphalt fuses more tightly,allowing the asphalt to exert its better bonding properties.（3）The self-made adhesive layer material is used in the laboratory simulation site,cement concrete and asphalt mixture are bonded into composite specimens and drilled to test the interlayer shear and pull strength,and the factors are determined by the amount of spraying and temperature.Analysis:The recommended optimal spraying amount is 0.85 kg/m~2～0.86 kg/m~2.Within this spraying amount range,the strength of the specimen against shearing and pulling is the best;and through linear correlation analysis,it is obtained,the tensile strength has a strong correlation with the change of temperature,and the correlation coefficient can reach 0.995.（4）In order to accurately evaluate the mechanical properties between the overlay and the old pavement,finite element software was used to simulate the mechanical behavior of the contact between the overlay and the old pavement.The force condition has a great influence.The larger the friction coefficient,the better the contact effect and the better the ability to resist deformation. |
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