Literature Review on the Discrete Element Method in Asphalt Mixtures

Abstract

Asphalt mixtures are commonly used in pavement engineering, especially for highway construction. The mechanism exploration and analysis of pavement distress are the main challenges for researchers and industry managers. Thereby, it is important to understand their properties and interaction mechanisms in asphalt mixtures. It is difficult to conduct some sophisticated or microscale tests in the laboratory, and numerical simulation and virtual tests can be solutions for these cases with low costs. The Discrete Element Method (DEM) is a promising tool for researchers to undertake these tasks. This paper mainly summarized and analyzed the research progress and development prospect of DEMs in asphalt mixtures from a series of technical sections. The laboratory test results were often used to calibrate the DEM simulations as well as Two-dimensional (2D) and Three-dimensional (3D) modeling. Several modeling methods were developed to generate digital samples, like user-defined, image-based, random-modeling. In addition, the conclusions can be referenced by researchers for the development of numerical simulations.

Review on Load Transfer Mechanisms of Asphalt Mixture Meso-Structure

“…Numerical simulation tests are more suitable for characterizing the load transfer mechanism of asphalt mixtures. Furthermore, the combination of DIP and a numerical simulation method, which is the recommended method to be used in current and future research, can provide a better way to investigate the load transfer mechanism of an asphalt mixture [ 52 , 53 ]. Based on the meso-scale structure of asphalt mixture obtained by the DIP method, the asphalt mixture load transfer characteristics can be studied by a numerical simulation.…”

“… The indirect tensile (IDT) test of asphalt mixtures [ 52 ]: the green balls represent aggregates; the blue balls represent mastic; the white balls represent air voids; the black line represents the force chain. …”

Investigation on strength characteristics and mechanism of cold mix based on geopolymerization reaction

“…Fluorescence microscopy enables direct observation of the microstructure in the cold mixed asphalt, clearly presenting the interfacial bonding between the geopolymer, asphalt, and aggregates. Meanwhile, discrete element simulation establishes a virtual model on the computer to simulate the loading damage process of the Marshall test, assessing the internal mechanical responses of the mixture (Xiao et al, 2021;Yao et al, 2022). The two techniques are complementary to each other, with one directly characterizing the microscopic morphology and the other simulating the microscopic mechanisms, jointly revealing the strengthening mechanism of the geopolymer modification.…”

Mesoscopic Analysis of Fatigue Damage Development in Asphalt Mixture Based on Modified Burgers Contact Algorithm in Discrete Element Modeling

“…For instance, 2D DEM is unable to sufficiently account for aggregate interlocking and irregular aggregate shapes. The 3D models have advantages in these respects but the procedures of creating and optimizing them are computationally more expensive due to the complexity of interconnections and structures [26]. You et al [27,28] developed 2D and 3D discrete element models to simulate the dynamic modulus test of asphalt mixtures and predict the dynamic modulus of asphalt mixtures using image processing and 3D digital generation technologies.…”