Understanding the Stiffness of Porous Asphalt Mixture through Micromechanics

Hong Zhang,Kumar Anupam,Cor Kasbergen,Sandra Erkens,Tom Skarpas

doi:10.1177/0361198121999060

Abstract

Micromechanics, which can be used to relate the properties of a composite to the properties of individual constituents, is considered a good approach to understanding the fundamental mechanisms behind the behavior of asphalt materials. Compared with the semi-empirical and numerical micromechanical models, analytical micromechanical models do not need calibration factors. In addition, they can provide analytical solutions on the basis of a series of assumptions. Using these models, researchers have separated the effects of different stiffening mechanisms (i.e., the volume-filling reinforcement, the physicochemical reinforcement, and the particle-contact reinforcement) for mastic. However, similar research work has not been conducted for asphalt mixtures and, moreover, the characteristics of the particle-contact reinforcement have not been deeply analyzed by researchers. Therefore, this paper aims to understand the stiffness of asphalt mixture through micromechanics. The focus of this study was on porous asphalt mixture where particle-contact reinforcement plays an important role in its behavior. The stiffening effects of different mechanisms were separated using analytical micromechanical models. The effects of temperature/frequency and the properties of the matrix phase on the stiffening effect of the particle-contact reinforcement were analyzed.

Highlights

KnowledgeDifferential ModelAs introduced above, various analytical micromechanical models can estimate the stiffening effect of the volumefilling reinforcement
As expected, at high frequencies, the stiffening effect of the volume-filling reinforcement is dominant over the particle-contact reinforcement, whereas at low frequencies, the contributions from the particle-contact reinforcement are much more significant
This paper has determined the stiffening effects of the volume-filling reinforcement and the particle-contact reinforcement for porous asphalt (PA) mixes using the theory of micromechanics

Summary

Introduction

Various analytical micromechanical models can estimate the stiffening effect of the volumefilling reinforcement. In the first step, inclusion particles with a small volume of V2(1) are added into the matrix phase with a stiffness tensor of C1. The obtained effective medium 1 with stiffness of Ceff[1] is further considered to be the matrix phase in the second step. This iterative process is continued until the volume fraction of the inclusion particles is equal to the total volume fraction of the inclusion phase in the composite

Objectives

Results

Conclusion