Research On Mechanical Properties And Crack Resistance Of Reclaimded Asphalt Pavement Flexible Subbase

Reclaimded Asphalt Pavement recycling technology is an effective way to solve the waste recycled and environmental pollution, however, Recycled Mixture exists deficiencies reflected in both weaker performance and poor water stability, prones to early damage. As nonlinear properties and crack resistance of pellet-like materials are widely used, this paper presents the idea of full-scale RAP material as road reconstruction flexible subbase of pavement structure.Firstly, this paper introduces the domestic and foreign research status that RAP doped ratio impacts Recycled Mixture and pellet interlayer delays pavement’s reflective cracking.Secondly, analyzes the rationality of RAP material as flexible subbase, and gets the vertical stress distribution within the structure layer and vertical stress level considering the influence of overload, and then uses the pre-evaluation model of granular material’s permanent deformation to analysis its plastic deformation.In order to evaluate the gradation composition of RAP, experimental study was performed on the basis analysis, and then determines the reasonable gradation of RAP flexible subbase on the test section. In addition, through the analysis of basic mechanical properties and bearing capacity, determines the resilient modulus of RAP and gets the correlation between the resilient modulus and the compaction degree.By using the finite element software ANSYS and combining with the theory of linear elastic fracture mechanics, the numerical simulation of RAP flexible subbase asphalt pavement existing the cracks is built. Through the interaction integral method, obtains the variation rule between crack tip stress intensity factor(KI, KII) and RAP subbase thickness, modulus and overloading rate. And then, combining with the design standard of asphalt pavement structural combination design, determines reasonable layer thickness and modulus of RAP material as reconstructed road subbase, finally, gets the typical pavement structure of full-scale RAP flexible subbase asphalt concrete road on reconstructed road, in order to provide the reference for practical application.