Mechanical Analysis Of Pavement Overlay Structure Of AC+PCC With Roadmesh

Aiming at the ubiquitous problems of reflective cracking in asphalt overlay layer on existing cement concrete pavement, a new type of pavement reinforcing technology with RoadMesh was introduced. A three dimensional finite element method was applied to carry out the numerical simulations for the mechanical responses of RoadMesh reinforced AC+PCC pavement overlay structure, and compare the change laws of various mechanical analysis indexes with and without reinforcement, thus the mechanism of RoadMesh reinforcement were deeply researched.(1) By means of analyzing the work characteristics of AC+PCC pavement overlay structure, the assumptions, indicator indexes and load model were determined for the mechanical analysis of pavement structure, and the three dimensional finite element model was created. Then the selection of element types and the mesh generation were carried out, and the vertical dimensions of subgrade and the worst loading position were also confirmed.(2) After the appropriate scope of calculating parameters was selected and the orthogonal test planning table of 10 factors and 9 levels was arranged based on orthogonal test design, the numerical simulations of three dimensional finite element were analyzed for the AC+PCC pavement overlay structure. The influence laws of various mechanical responses under changing various parameters of the AC+PCC pavement overlay structures were compared with and without RoadMesh reinforcement. The results show that, by comparing with the unreinforcement and in the case of same factors and levels, the RoadMesh reinforcement decreased the maximum tensile stress (26.23%-34.09%) and the maximum shear stress (16.65%-21.32%) at the bottom of AC layer, the deflection difference of top slabs (8.87%-10.96%), and the deflection at pavement surface (1.06%-1.44%), respectively. As a result, conclusion could be drawn that RoadMesh reinforcement has efficiently reduced the reflection and development of cracks.(3) RoadMesh, geotextile and geogrid were respectively chosen as the reinforced materials to compared the influence laws of various mechanical responses of AC+PCC pavement overlay structure under the reinforcement of different materials. Results show that, compared with the unreinforced structures and after the reinforcement with RoadMesh geotextile and geogrid, the maximum tensile stresses at the bottom of AC layer decrease about 30.99%,9.73% and 13.77% respectively; the maximum shear stresses at the bottom of AC layer decrease about 19.47%,4.58% and 9.30%, respectively; the deflection difference at top slabs decrease about 10.19%, 2.55% and 3.12% respectively; and the deflections at pavement surface decrease about 1.25%,1.05% and 0.81% respectively. Therefore, the capacity of reflective cracks resistance of RoadMesh reinforcement was superior to the geotextile and the geogrid.In brief, the results of this thesis laid a scientific foundation for the further promotion and application of RoadMesh reinforced AC+PCC pavement overlay structure.