Investigating the Functions of Particles in Packed Aggregate Blend using a Discrete Element Method

Abstract

In asphalt mixture, aggregates account for up to 90% of the total volume and play an important role in the mechanical characteristics of asphalt mixture. The proportions of fine and coarse aggregates in gradation, as well as the function of aggregate particles, are important factors for the skeleton structure performance of asphalt mixtures. However, the existing asphalt mixture design methods are mostly based on empirical methods, where the non-uniformity and complexity of the composition of asphalt mixtures are not fully studied. In this study, the skeleton structure of aggregate mixture and function of aggregate are studied and analyzed using the Discrete Element Method (DEM). The Particle Flow 3D (PFC3D) DEM program is used to perform the numerical simulation. The average contact number and interaction forces by aggregate particles of different sizes are obtained and studied. The skeleton structure of aggregate mixture and function of aggregate particles are further analyzed from the meso-structural perspective.

Review on Load Transfer Mechanisms of Asphalt Mixture Meso-Structure

“…The application of the MRE method requires high technical requirements, and the contact structure obtained has certain errors because the data processing accuracy cannot be reached. For the numerical simulation test methods, such as the finite element method [ 2 , 3 , 50 , 51 ] and discrete element method [ 5 , 7 , 28 ], it is more convenient to analyze the influence of a single factor and to exclude the cross influence of many factors on the load transfer mechanisms. It can also reduce time consumption and cost, using the numerical simulation test method.…”

“…In many studies, the contact force between particles refers to the normal component [ 5 , 7 , 9 , 22 ]. Generally, contact forces are classified as strong and weak, and the strong constitutes the main load-bearing system in asphalt mixtures.…”

“…While 0.3 mm to 1.18 mm, which also contributes more than 50%, is a crucial sieve size range for stabilizing the basic structure. A series of DEM tests were conducted by Miao et al [ 7 ] to examine the contact force characteristics of various sized particles in aggregate blends. To characterize the load-bearing contribution of each size particle in aggregate blends, an indicator was suggested.…”

“…The study of the load transfer mechanism of the meso-structure of asphalt mixture provides a new perspective for the study of classical problems, and can also induce new understanding. In the past decades, a variety of methods have been introduced to study the load transfer mechanisms, such as the photoelastic experiment method, digital speckle method, digital image processing (DIP) technology, discrete element method (DEM) simulation, finite element method (FEM) simulation, and the combination of multiple methods [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ].…”

A Random Angular Bend Algorithm for Two- Dimensional Discrete Modeling of Granular Materials

“…The discrete element method (DEM), originally developed by Cundall in 1971 [4,5], provides a convenient way to obtain particle information on multiple scales, and gradually becomes an effective tool to study the mechanical behaviors of granular materials [6,7,8,9]. To investigate the effect of particle shape, various shapes have been created to approximate the realistic shape of particles (such as circles and spheres [10,11,12,13], ellipses and ellipsoids [14,15], cylinders [16], polygons, and polyhedrons [17,18,19]). However, a considerable number of them are idealized geometric shape, which is unable to capture the behavior of actual or natural granular materials better.…”