APPLICATION OF MESO-MODEL OF CONCRETE LOW-VELOCITY IMPACT IN PAVEMENT

Abstract

Concrete pavement is one of the typical highway structures at home and abroad. Most of the existing research on the performance of concrete pavement is based on the macroscopic angle of view. The complex meso-structure inside is ignored. Due to the incomplete research on concrete pavement structure, it is difficult to reveal the physical mechanism of concrete pavement deformation and damage. In order to understand the failure mechanism of concrete pavement more clearly, this paper started from the microscopic perspective. Firstly, based on the experimental phenomena, a multi-grade aggregate model was randomly placed in the concrete slab, and the interface between the aggregate and mortar was generated at the same time to establish a three-dimensional three-phase mesoscopic bone and the finite element calculation model of the material. Secondly, the damage effect of concrete specimens in homogeneous modeling, meso-modeling and experimental phenomena were compared to verify the accuracy of the selected concrete material parameters and the feasibility of meso-modeling method. Finally, the concrete failure form under three different aggregate contents and the influence of internal aggregate content of the concrete pavement on the mechanical properties of the concrete pavement were analyzed. The calculation results showed that compared with the macroscopic simulation, the mesoscopic model was more consistent with the experimental phenomena of the failure effect of the concrete specimens. And the numerical simulation results with the aggregate content of 46.6% were the most consistent with the experimental results. Comparing the failure modes of concrete specimens with different aggregate contents, it was found that the concrete specimens with an aggregate content of 60.6% have a lighter degree of damage. When the aggregate content was 30.6%, the impact tooth penetrated half of thickness of the concrete specimen, and the aggregate content is 60.6% of the impact teeth penetrated one third of the concrete specimen. Therefore, the higher the aggregate content is, the stronger the ability of the concrete specimens has to resist damage.