Analysis of gestation, emergence and development behavior for asphalt microcrack topography based on FEM-MD

Abstract

To intuitively examine the gestation, emergence and development behavior of asphalt microcrack topography, scanning electron microscopy (SEM), finite element method (FEM) and molecular dynamics (MD) were combined to explore the spatial evolution behavior of asphalt micro-topography. Initially, the typical grayscale images of asphalt micro-topography were obtained by asphalt SEM tests, and the spatial distribution characteristics of grayscale pixels were studied. Subsequently, three-dimensional models of asphalt micro-topography were created based on grayscale images, and the gestation and emergence behavior mechanism of asphalt microcrack were revealed by FEM simulation calculation. Finally, combined with the MD simulation, the development behavior mechanism of asphalt microcrack were surveyed from molecular scale. The results show that the uneven distribution of temperature stress can be caused by the uneven asphalt micro-topography, and asphalt microcrack can be gestated in smooth micro-topography and fold micro-topography, and emerged in crack micro-topography. The development of asphalt microcrack can be considered as the game results of temperature self-healing and temperature stress cracking. The study systematically explores the spatial evolution behavior of asphalt microcrack topography, which can help to reveal the intrinsic mechanism of asphalt material property degradation.