Accelerated Loading Experiment Research On Splicing Performance Of Widen Pavement

With the rapid development of national economy,the traffic volume of expressways is increasing sharply,which resulting in the original two-way four-lane expressways can not size up the increasing traffic volume,reconstruction and extension of expressway has an important significance to improve road capacity.In this paper,the interlayer performance of five kinds of reinforced materials was studied through indoor model tests,and the influence of reinforced materials on the mechanical response in the joint part of the widen pavement was studied based on the accelerated loading experiment,at the same time,finite element simulation under non-uniform distributed load and moving load was carried out.Five kinds of reinforced materials were selected for rutting test and interlaminar shear test,three types of steel wire mesh were selected for pull-out test.Steel wire mesh,fiberglass grid and self-adhesive geotextile have a positive effect on improving the rutting resistance of composite specimens.The anti-rutting ability of composite specimens reinforced with steel wire mesh was significantly improved because of stronger interlocking effect with the ag gregate due to the "plane confinement effect".The steel wire mesh improve the shear resistance of composite specimen due to the good "passive shear" effect from the interlocking effect between steel wire mesh and aggregate.The self-adhesive geotextile and fiberglass grid have an adverse effect on the interlayer shear strength due to the isolation of pavement layer interface.The pull-out resistance and anchoring stability of reinforced Ω-type steel wire are greatly improved,and the increased diameter of reinforced steel wire could also improve anchoring performance of Ω-type steel wire mesh.The Ω-type hump could significantly enhance the anchoring performance of steel wire mesh between structural layers as a result of the frictional resistance between st eel wire and interlayer aggregate and "end bearing" effect of Ω-type hump after deformation of theΩ-type mesh.The experimental section of ring road was designed and paved,static and dynamic loading tests were carried out to analyze the mechanical response of the joint part of reconstructed and expanded asphalt pavement.Compared with the traditional strain gauge,the fiber grating GFRP sensor is more fragile,but its sensitivity is better than asphalt concrete strain gauge;the progressive loading curves of the asphalt concrete strain gauge,the fiber grating GFRP sensor and the earth pressure gauge are linear.The different test data between fiber grating GFRP sensor and traditional strain gauge is mainly due to the difference in gauge length and modulus of two kinds of sensors.With the increasing of driving speed,the peak value of compressive strain of asphalt layer,the peak value of the tensile strain of the base course and the peak value of the compressive stress at the top of the soil course are gradually decreased.The strain at the bottom of the asphalt course and the bottom of the foundation course is greatly affected by the speed of the vehicle,a nd the stress at the bottom of the base layer is less affected by the speed of the vehicle.The driving speed will affect the loading frequency of asphalt layer,and the driving speed is positively correlated with the loading frequency.The steel wire mesh could reduce the compressive strain at the bottom of the asphalt layer because of its interlocking effect,and the five kinds of reinforced materials are due to the "membrane effect","plane confinement effect" and the "stress diffusion effect" increases the bearing capacity foundation course and soil course.The simulation analysis of reinforced asphalt pavement was carried out thr ough ABAQUS finite element software.The simulation and experiment results show that the effects of five reinforced materials in improving the bearing cap acity of foundation course and soil course are in descending order: steel wire mesh,self-adhesive geotextile and fiberglass grid.