Preparation Parameter Analysis and Optimization of Sustainable Asphalt Binder Modified by Waste Rubber and Diatomite

Hanbing Liu,Yubo Jiao,Liuxu Fu,Mengsu Zhang

doi:10.1155/2018/3063620

Abstract

In this study, crumb rubber and diatomite were used to modify asphalt binder. Wet process was adopted as a preparation method, and the corresponding preparation process was determined firstly. The effects of six preparation parameters (crumb rubber concentration, diatomite concentration, shear time, shear speed, shear temperature, and storing time) on properties of modified asphalt binder (penetration at 25°C, softening point, ductility, viscosity at 135°C, elastic recovery, and penetration index) were investigated, and multiresponse optimization was conducted using the response surface method. The results revealed that softening points, viscosity, elastic recovery, and penetration index increase, while penetration and ductility decrease with the increase of crumb rubber concentration. Softening points, viscosity, and penetration index increase, while penetration and ductility decrease with the increase of diatomite concentration, which presents little influence on elastic recovery of binder. Shear temperature presented significant effects on penetration, softening point, viscosity, and ductility. Shear speed, shear time, and storing time have similar effects on binder properties because of their similar mechanism of action. Based on the model obtained from the response surface method, optimized preparation parameters corresponding to specific criteria can be determined, which possess favorable accuracy compared with experimental results.

Highlights

Disposal of industrial wastes has become a critical problem in the world under the promotion of environmental management and mission of sustainable development [1, 2]
Experimental scheme for property analysis of compound-modified asphalt binder under the effect of preparation parameters was established based on the response surface method (RSM). is scheme is composed of 54 experimental groups including 6 replicates at the central point, which is much less than a full test plan 36 729. ree specimens are included in each group, and the corresponding average value is regarded as a representative one
Crumb rubber and diatomite compound– modified asphalt binder was prepared. e effects of preparation parameters on properties of modified asphalt binder were investigated, and multiresponse optimization was conducted using the response surface method. e following conclusions can be obtained: (1) Response surface method is a suitable method for preparation parameter analysis and optimization of crumb rubber and diatomite compound–modified asphalt binder, which can effectively reduce the number of groups

Summary

Introduction

Disposal of industrial wastes has become a critical problem in the world under the promotion of environmental management and mission of sustainable development [1, 2]. CR-modified asphalt and corresponding mixture possess favorable environmental benefits. Farina et al [5] demonstrated the environmental results of recycled materials in bituminous mixtures for pavement wearing courses using life cycle assessment (LCA) methodology. Results reveal that the use of wearing course containing asphalt rubber obtained by the wet process presents significant benefits for energy saving, environmental impact, human health, preservation of ecosystems, and minimization of resource depletion. Results show that the global environmental performances of the rubberized asphalt road are improved by 30–40%. La Rosa et al [7] evaluated the environmental benefit of using recycled waste tyres in mixture with virgin rubber. Yu et al [8] evaluated the environmental burdens of plastic-rubber asphalt (PRA) mixture and styrene-butadiene-styrene (SBS) asphalt mixture by using a cradle-to-gate LCA model.

Methods

Results

Conclusion