Modeling of the Complex Modulus of Asphalt Mastic with Biochar Filler Based on the Homogenization and Random Aggregate Distribution Methods

Yushuai Wu,Ketong Liu,Feiting Shi,Peng Cao,Zhen Leng,Xuhao Wang,Zhifei Tan,Changjun Zhou

doi:10.1155/2020/2317420

Abstract

The disposal of agricultural straw has been a severe environmental concern in China and many other countries. In this study, the complex modulus of using biochar converted from straw as an alternative mineral filler in asphalt mastic was investigated through both laboratory tests and modeling. The experimental results indicated that the biochar can provide asphalt mastic higher stiffness than the conventional granite mineral filler. It was believed that the special porous structure of biochar providing a thicker coating layer of mineral filler increases the stiffness modulus of asphalt mastic. To consider this factor into the micromechanical model, a modified generalized self-consistent model (MGSCM) with a coating layer was proposed. Besides, the finite element (FE) microstructural model with a coating layer generated by random aggregate distribution method was used to numerically evaluate the effect of the coating layer on the complex modulus of asphalt mastics. The predicted results indicated that the generalized self-consistent model (MGSCM) with a coating layer is an efficient and accurate model for predicting the complex modulus of asphalt mastics. Moreover, the FE modeling proved that the coating layer can significantly improve the complex modulus of asphalt mastics. Therefore, the experiments and modeling carried out in this study provided insight for biochar applications to improve the performance of asphalt mixtures.

Highlights

Academic Editor: Candido Fabrizio Pirri e disposal of agricultural straw has been a severe environmental concern in China and many other countries
The finite element (FE) microstructural model with a coating layer generated by random aggregate distribution method was used to numerically evaluate the effect of the coating layer on the complex modulus of asphalt mastics. e predicted results indicated that the generalized selfconsistent model (MGSCM) with a coating layer is an efficient and accurate model for predicting the complex modulus of asphalt mastics
It is worth noting that a significant increase in dynamic modulus can be observed with the biochar substitutions from 0% to 100% and a 50% modulus increase can be achieved with a 100% biochar substitution

Summary

Introduction

Academic Editor: Candido Fabrizio Pirri e disposal of agricultural straw has been a severe environmental concern in China and many other countries. The complex modulus of using biochar converted from straw as an alternative mineral filler in asphalt mastic was investigated through both laboratory tests and modeling. It was believed that the special porous structure of biochar providing a thicker coating layer of mineral filler increases the stiffness modulus of asphalt mastic. To consider this factor into the micromechanical model, a modified generalized self-consistent model (MGSCM) with a coating layer was proposed. Erefore, to accurately and efficiently predict the complex modulus and time-dependent characteristic of biochar filler asphalt mastic, a more rational micromechanical model is keenly desired Because these models generally cannot consider the effects of physiochemical reinforcement and particle interaction, the predictions always underestimate the modulus of asphalt materials [10, 26,27,28,29]. erefore, to accurately and efficiently predict the complex modulus and time-dependent characteristic of biochar filler asphalt mastic, a more rational micromechanical model is keenly desired

Objectives

Results

Conclusion