Study On Pavement Damage Mechanism And Repair Technology Of Aircraft Contact Zone

The ground zone area of the airport provides the key function of take-off and landing for the aircraft,but with the increase of the number of times of use,the surface structure is seriously damaged under the strong load,maintenance operation and environmental factors,the main manifestations are the rapid propagation of pavement cracks,the exposed surface aggregate,and the possible sudden shedding of aggregate.To reveal the mechanism of ground strip surface damage,based on the theory of fracture mechanics and damage mechanics,the micro-mechanics of pavement surface damage caused by degumming is studied in this paper,and the mechanism of pavement damage caused by frost heaving is discussed.According to the characteristics of the surface crack propagation caused by high-speed tire friction on the runway during takeoff and landing,the fracture mechanics models of the surface damage was constructed.According to the characteristics of high pressure water degumming,the analytical equation of stress intensity factor at crack tip was constructed.Based on the basic law of freezing and thawing of damaged pavement concrete,the equation of the influence of frost heaving effect on the damage of concrete pavement was established.The aim is to judge the degree of pavement damage and analyze whether it is necessary to repair the pavement in time.To further reflect the damage law of pavement,this paper constructs a two-dimensional meso aggregate model of concrete pavement surface under the original crack state and a crack model based on XFEM using Abaqus finite element software.,the effect of high-pressure forced sliding and vertical load on crack surface and the mechanical effect of crack under frost heaving are analyzed.Based on the analysis of the overall mechanical effect of the pavement surface layer,the results show that the crack will grow vertically and downward when subjected to aircraft load slip friction;when subjected to aircraft gravity load,the crack will grow 45° along the horizontal direction;the increase of the depth and width of the pavement crack under frost heaving will cause the crack tip stress field to increase,and the larger aggregate size can restrain the crack damage propagation.Under the condition of judging the damage degree of the pavement,the characteristics of the concrete damage on the ground pavement were given,based on the theory and technology of penetration bonding to improve the adhesive property,the paper has carried out the research of repairing technology under the condition of serious crack.Based on the analysis of the permeation adhesion law of different repair materials,the adhesion repair test of epoxy resin material was carried out.In order to study the influence factors of improving the repairing effect,the resin viscosity test,gel time test and bond performance test were carried out by controlling the mass ratio of epoxy resin to excipients and the working environment temperature.The permeability of the damaged surface is controlled by parameters,and the adhesion of the repaired surface is improved effectively.