Mesoscopic asphalt pavement response analysis using a random aggregate generation-based concurrent multiscale method

Abstract

Asphalt concrete (AC) layers in asphalt pavements are heterogeneous, but they are generally deemed as homogeneous in engineering practice, which cannot realistically reflect the complex mechanical behavior of asphalt pavement, particularly at finer scales. To resolve this problem, the present study developed a random aggregate generation-based concurrent multiscale method to simulate the mechanical response of asphalt pavement using ABAQUS software. In this method, the mesoscopic structure of AC with a 60 cm length was simulated in the vicinity of tire loading by a random aggregate generation method and embedded into a macroscale pavement model. To account for the effects of pavement structure and environmental factors, three thicknesses of AC layer (10 cm, 15 cm and 20 cm), two types of pavement structures respectively with a cement-treated base (CTB) and a granular base (GB), and two pavement temperatures (5 and 35℃) were adopted in the simulation. The maximum principal stress (MPS) values of fine aggregate matrix (FAM) within the region of interest were sorted and the values at the percentiles of 10%, 20%, …, 90%, 100% were extracted. Besides, the number of the elements with top 1% MPS values were evaluated. Specific statistical analysis was performed on these values to investigate potential damage behavior of the AC layer. The results showed that the MPS at the percentile of 100% is at least three times that at the percentile of 90%, which indicates considerable stress concentrations at the narrow gaps between coarse aggregates. Top-down cracking could be the main cracking pattern for the CTB and GB pavement at low temperatures, and bottom-up cracking may be the main damage mode for the GB pavement at high temperatures. Increasing the thickness of the AC layer may effectively reduce the stress level at top of the AC layer for the CTB pavement at low temperatures.