Study On The Crack Mending Materials Of Cement Concrete Pavement

For high in strength, good in durability, the cement concrete pavement have been widespread developed in the whole country, which the course increased continuously. But by the effect of modern traffic and environment facts, the pavement early damage appears incessantly, especially for the crack. As for the early microcrack, the asphalt and epoxy resin and some other organic material, which although have the ability of adhesion and occlude, it have consistent, age, high price and environment problems with cement concrete for pavement, are used for repaired by the road maintain apartment. Aiming at this situation, this paper choose the fine and normal cement as the base material for crack mend, and mix with polymer emulsion S400 and cinnamene and acrylate copolymer R161, which have the flexility and performance of adhesion and double constituent water resistance, to modify for researching the microcrack mend material of cement concrete pavement with the good consistence, excellent performance, construction convenience, economy and protecting environment.This paper at first analyzes the situation of cement concrete pavement design, construction and maintain systemically. The pavement damage and crack mechanism is a complicated problem. The pavement crack is the result of many facts having the comprehensive influence, and not only refer to the cement concrete material, pavement design theory and methods, but also have the relationship with the traffic load, the calculate theory and methods of temperature stress and other correlation subjects.By connecting with the special property of the pavement crack and the situation for material market to choose the modify material and base material for the crack mend, the experiment plan is scientific design.The flow property, groutibility, stability, fullweight ability and some rheological property are deeply studied in this paper, as the viscosity, setting time and groutibility are the control destination for the workability to optimize the mix design of the microcrack mend material with modified for cement concrete pavement. The hydration course, setting hardening, rupture and compressive strength, shrinkage deformation of the polymer modified cement are studied for the mechanical and pavement performance, and the contributory factors are discussed. The result shows that with the polymer emulsion S400 and R161 adding, the hydrate emission heat and setting hardening course of the cement have changed, and the rapture strength have increased, meanwhile, the flexility and shrinkage deformation property have improved.The success or failure of mend basing on the adhesion performance between cracks mend material and old cement concrete interface, this paper studies the adhesive test method and evaluation index, and simulate the pavement strengthening to design the test method for the bending adhesion strength and tensile-shear adhesion strength and bring up the evaluation index. The test result shows that adding the finecement with the S400, the bending adhesion strength improve above 20% than the non-modified cement, the R161 arrive at the 36% and the modified normal cement arrive at 30% at the same way.Base on analysis of the signification of the durability of the pavement microcrack mend material, the permeability resistance ^ corrosion resistance and wear resistance are deeply studied in this paper. The test chooses hydrochloric acid^ vitriol and glacial acetic acid as the corrosion medium, and takes the loss percentage of compressive strength after steeping as the corrosion resistance index. The text shows the S400 and R161 can considerable improve the corrosion resistance of modified cement material, and the degree of the increase is different with the kind of the polymer mix capacity and the kind of the cement. The wear resistance test shows when the ratio of the polymer and cement > 15%, the wear resistance improved notable. The tiny polymer granule can fill the aperture of cement paste, and hidden the absorption and permeability of moisture, than increase the permeability resistance.By XRTX DTA/TGN SEM^ mercury-infection method measuring aperture and many other modern phase analysis technology to study the hydration course N hydration product^ hydration mechanism ^ hardening paste micro-forming and void structure of the modified fine cement with S400 and R161. The study show that polymer emulsion in hardening cement can not only film forming sufficiency, but also infiltrate and permeate the hydration product and form the incontinuous ^ fill-compacted space reticular formation, which refines the material structure, and reduces the orientation of the hydration product, then the structure becomes more compact.This paper study systemic for the porosity of the modified fine cement with polymer emulsion^ void property and void structure for the first time, and analyze the diversification rule of void gradation with polymer mixing capacity and maintain age, meanwhile reveal the interrelation between the modified cement material with polymer, and structure and macro technology performance. This study has achieved some creative results.The two way of gray system theory and summation precedence evaluation have been used to evaluate with the multi index comprehensive property of polymer modified material, calculate and analyze the economics, define the applicable condition and range for all manner of material, and choose the mend material with excellent performance. This study has been tested in a certain express way for its crack mending, and the impression is good.