Study On The Quick Penetration Patching Technology Of Micro-cracks In Asphalt Concrete Pavement

Due to the effects of environment,construction conditions,traffic loading and many other factors,quantities of micro-cracks with the width less than 2 mm,even less than 1 mm inevitably occur in asphalt concrete pavement.If not repaired timely,the cracks will extend further and ultimately grow into more serious damages like slurry pump and pit,etc,which seriously affects the pavement life,the comfort and safety of driving.Currently,the existing patching technology is mainly for the repairing of the wider cracks,it is necessary to develop a quick penetration patching technique for micro-cracks in asphalt concrete pavement.On the basis of the existing research results,three kinds of patching materials which can quickly cure at room temperature,meet the performance requirements of pavement materials and has lower viscosity have been synthesized,namely acrylic ester graft epoxy resin patching material,epoxy methacrylic acid ester patching material and maleic anhydride modified asphalt patching material.By measuring the change rules of viscosities and the initial curing time of the patching materials,and observing the state of the initial cured products,it can conclude that these three materials' initial viscosities are all very low.Nevertheless the acrylic ester grafted epoxy resin patching material is too sensitive to the prepolymeric time;the epoxy methacrylate patching material' s curing reaction is too rapid to control;Besides there exists an serious segregation phenomenon and the cured products present obvious vertical inhomogeneity.Compared with the first two materials,maleic anhydride modified asphalt patching materials' preparation process is the simplest and its cured product is uniform,which makes it the most appropriate patching material.By increasing the amount of modified asphalt and measuring the change rules of the materials' viscosities,concluding that the influence of the amount of modified asphalt for the cure reaction.Finally,in considering of the actual stress states of the patching material under working conditions,the tensile shear strength and the adhesion strength of the patching materials are evaluated by steel-steel tensile shear test and steel-steel adhesion test.The results show that when the amount of modified asphalt is less than 10wt%,the maleic anhydride modified asphalt patching material has a good shear and adhesion strength and it is helpful to repair micro-cracks.The repair operation should be completed as soon as possible.