Investigation on Preparation Process and Storage Stability of Modified Asphalt Binder by Grafting Activated Crumb Rubber.

Yongning Zhang,Songtao Lv,Yueming Yang,Xinghai Peng,Juan Xie

doi:10.3390/ma12122014

Yongning Zhang, Songtao Lv + Show 3 more

Open Access

https://doi.org/10.3390/ma12122014

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Abstract

According to the theory of molecular design, crumb rubber was grafting activated with acrylamide and then used as asphalt binder modifier. An orthogonal three-factor, three-level test was designed to optimize the preparation process of modified asphalt. Softening point, viscosity, rutting factor, ductility, stiffness modulus and creep speed index were selected as evaluation indicators to study the effects of rubber content, shear time and shear temperature by variance analysis and range analysis. The results show that the rubber content had a significant impact on the performance of modified asphalt with grafting-activated crumb rubber, while the shear temperature and shear time had little effect. The grafting activated crumb rubber content of 20%, shear temperature of 170–190 °C, and shear time of 90 min was determined as the reasonable preparation process. Modified asphalt with common crumb rubber (CRMA) and modified asphalt with grafting activated crumb rubber (A-G-R) were prepared, respectively, using the reasonable process to analyze the influence of grafting activation of crumb rubber. The results indicate that A-G-R had smaller softening point difference, lower segregation index and more stable and uniform dispersed phase.

Highlights

Asphalt pavement has become a main type of pavement structure all over the world because of excellent performance [1,2]
Many researchers have shown that scrap tires can be pulverized and added to asphalt to improve the rutting resistance at high temperature, crack resistance at low temperature, aging resistance and fatigue resistance of asphalt pavement, and the environmental pollution can be alleviated at the same time [4,5,6,7]
A bending beam rheometer produced by Cannon Instrument Company was used to carry out low temperature creep tests

Summary

Introduction

Asphalt pavement has become a main type of pavement structure all over the world because of excellent performance [1,2]. With the growth of the traffic volume, neat asphalt binder is difficult to meet modern transport development demands and needs to be modified. Scrap tires called “black pollution” are being generated and accumulated in vast quantities and causing severe environmental issues, so the reclamation of them has become a major concern [3]. Due to the great differences in molecular weight, density, solubility parameters and chemical structure between rubber particle and asphalt, crumb rubber modified asphalt generally has poor thermal storage stability and is easy to segregate [8], which brings inconvenience to the transportation and use of rubber asphalt [9], and seriously restricts the practical application and rapid development of crumb rubber modified asphalt

Methods

Results

Conclusion