The Research On The Mechanical Properties Of Rubber Concrete Pavement Under The Condition Of Bottom Void

Rubber concrete can effectively use waste rubber,and has the advantages of good toughness,ductility,wear resistance,noise reduction and fatigue resistance.Rubber concrete pavement is a new type of environmentally friendly concrete pavement,which is characterized by smooth,wear-resistant,anti-slip,solid,etc.,can improve driving safety and comfort,and extend the service life of the pavement.At present,the research on rubber concrete pavement is relatively less in China,and the design methods which can be used to guide the actual pavement structure are not mature.The mechanical properties of rubber concrete pavement are analyzed,and the mechanical mechanism of pavement slab bottom stripping is emphatically studied,so as to provide some theoretical reference for engineering practiceThe mechanical properties of rubber concrete pavement with slab bottom void are tested.The void area is preset at the corner of base slab,and the strain of pavement slab under load is detected.The results show that the maximum tensile stress is mainly affected by void area,thickness and load.The stress value of the panel at the corner of the void area is larger,about 1-5 times of that at the edge of the void.The model of the bottom void of the rubber concrete pavement is established by using finite element software ABAQUS.The three variables of the void area,the thickness of the surface layer and the size of the load are input,and the simulated stress value of the void pavement is obtained.The simulated value is consistent with the change rule of the experimental value,which verifies the accuracy of the simulation.Compared with the structure of ordinary concrete pavement,the maximum tensile stress at the bottom of the slab layer of rubber concrete pavement in the middle of longitudinal seam edge,the middle of transverse seam edge and the corner position is obviously reduced.The most disadvantageous load position of the rubber concrete pavement is the angle of the surface slab.The deformation capacity of rubber concrete pavement is stronger,which presents the characteristics of flexible pavement to some extent.The maximum tensile stress of the panel is mainly affected by the void area,the thickness of the panel and the thickness of the base layer.Rubber concrete pavement exhibits flexible characteristics,and shows better resistance to cracking and deformation under the condition of void,which can effectively reduce the possibility of pavement diseases.Under the action of temperature gradient,compared with ordinary concrete pavement,the maximum tensile stress of rubber concrete pavement in the middle of slab angle,longitudinal joint edge and transverse joint edge decreased by 79.6%,37.9% and 58.1% respectively.The change of panel temperature stress is related to whether it is void or not,which is less affected by void area,but the vertical displacement is significantly affected by temperature gradient.The maximum tensile stress and vertical displacement of the surface layer increase with the increase of the thickness of the surface layer,and decrease with the increase of the thickness of the base layer,but the change range is small.Based on the finite element model of rubber concrete pavement with slab bottom void and sensitivity analysis of various structural parameters,the transformation relationship between void and no void fatigue stress is proposed,so as to determine the fatigue life calculation formula of pavement slab under void condition.This study has a certain guiding significance for the design of rubber concrete pavement.