Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

Jie Ji,Luhou Liu,Di Wang,Hui Yao,Zhanping You,Zhi Suo

doi:10.1155/2017/2473283

Abstract

The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR) to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS) modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM) model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

Highlights

The design method of asphalt pavement in China is based on the static and elastic layer system models [1]
The experimental plan of this study includes the following: (1) prepare three types of modified asphalt binders based on the SK-90 base asphalt binder, including StyreneButadiene-Styrene (SBS) modified asphalt binder, Direct Coal Liquefaction Residue (DCLR) modified asphalt binder, and DCLR-composite modified asphalt binder; (2) design four asphalt mixtures based on the gradation of AC-20 (AC: Asphalt Concrete), which were SK-90 asphalt mixture, SBS modified asphalt mixture, DCLR modified asphalt mixtures, and DCLR-composite modified asphalt mixtures; (3) obtain the dynamic moduli of the asphalt mixtures and analyze viscoelastic properties of the asphalt mixtures; (4) establish a CAM model of the asphalt mixtures
The dynamic modulus is the ratio of stress to strain under different conditions, and the phase angle indicates the viscous part of asphalt mixtures

Summary

Introduction

The design method of asphalt pavement in China is based on the static and elastic layer system models [1]. The NCHRP-629 report reveals that the durability of asphalt pavement can be evaluated using the dynamic modulus of asphalt mixture [6]. In the specifications of American Association of State Highway and Transportation Officials (AASHTO), the design guideline for new pavement and regenerated pavement 2002 and the guideline for asphalt pavement mechanics-empirical design method (2002) was put forward by the NCHRP program [13, 14], and the dynamic modulus of asphalt mixtures can be considered one of the essential parameters in pavement design. The master curve of the dynamic modulus was plotted using the Christensen-Anderson-Marasteanu (CAM) model, and the viscoelastic properties of asphalt mixture were characterized [16, 17]. The DCLR is mainly used as a fuel for heating, which causes serious environmental pollution and reduces its economic value and leads to a waste of valuable resources

Objectives

Methods

Results

Conclusion