Study On Mechanical Properties Of Polypropylene Filament Geotextile And Prevention Of Reflective Cracks

Highway engineering construction is no longer a difficult problem today with the rapid development of science and technology,especially the grasp of the characteristics of traditional engineering materials makes the construction period of highway engineering shorter and shorter,but the following problem is how to improve the service life of the project,from the initial construction point of view,the application of geosynthetics reinforcement and crack prevention technology can improve the service life of the project,reducing maintenance costs,reduce the actual project cost.(1)To sort out the ways of reflective cracks in the base of pavement structure,based on the theory of fracture mechanics,the stress and displacement solutions of crack tip during crack propagation are given,the stress intensity factor(SIF),an important parameter for explaining the propagation state of crack tip,is explained conceptually,the general form of stress intensity factor and the criterion of stress intensity factor in crack instability are supplemented,the propagation process of pavement cracks under impact load and the shape of the plastic zone at the crack tip are defined,the mechanism process of crack prevention geotextile restraining crack propagation is analyzed;(2)The performance evaluation of engineering parameters of crack-proof geotextile specimens is carried out,the tensile strength was verified by wide strip tensile test,the trapezoidal tear test was carried out to verify the tear resistance of crack-proof geotextiles,CBR bursting test was carried out to verify the bursting resistance of crack-proof geotextiles,the longitudinal and transverse fracture strength,tearing strength and bursting strength were analyzed,it is concluded that the engineering application parameters of crack-proof geotextiles are good,at the same time,the key parameters of geotextiles with different specifications of polyester filament are compared,it is concluded that the physical and mechanical parameters of crack-proof geotextiles are better than those of polyester filament geotextiles;(3)The three-dimensional model of anti-crack geotextile pavement structure is established by using finite element software,by changing the modulus of structural layer and the thickness of crack-proof geotextile,the stress intensity factor and the regional state of the fracture are analyzed,the mechanism of crack-proof geotextiles is deduced from the viewpoint of energy,it is concluded that crack-proof geotextiles can effectively inhibit crack propagation,at the same time,the stress expansion state model of crack-proof geotextiles is established,it is concluded that the shape change of crack-proof geotextile is the same as that of plastic zone at crack tip when it resists crack cracking;(4)Road condition assessment based on actual projects,the crack-proof geotextile is used to reinforce the actual pavement,summarize the technical parameters.Combining with the physical and mechanical test performance test finite element numerical simulation and engineering parameter establishment of crack-proof geotextiles,this paper draws a conclusion that crack-proof geotextiles have certain effect on crack prevention of base course,it is concluded that crack-proof geotextile has certain effect on crack prevention of base course,it provides engineering reference for the application of geosynthetics in highway engineering and other engineering.There are 77 pictures,9 tables and 69 references.