Design of SBS-Modified Bitumen Stabilizer Powder Based on the Vulcanization Mechanism

Wengang Zhang,Zhirong Jia,Longting Ding

doi:10.3390/app8030457

Wengang Zhang, Zhirong Jia + Show 1 more

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https://doi.org/10.3390/app8030457

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Abstract

In order to improve the problem of the bad thermal storage stability of Styrene-Butadiene-Styrene Block Copolymer Modified Bitumen (SBS-modified bitumen), the vulcanization reaction was selected as the basic mechanism for the research and development of the stabilizer. Sulfur, tetramethylthiuram disulfide (TMTD), zinc oxide, butylated hydroxytoluene (BHT), kaolin (Al2O3·2SiO2·2H2O) and carbon-white (SiO2) were used as raw materials, and 32 kinds of components with different contents of raw materials were designed. The 48-h segregation softening point and other modified bitumen technical indicators, such as ductility, penetration, penetration index, viscosity, and so on, were tested and analyzed. The fluorescence microscope test was also conducted to explore the crosslinking situation based on the vulcanization reaction. The results show that the component with good performance of the SBS-modified bitumen stabilizer powder was S:TMTD:ZnO:BHT: Al2O3·2SiO2·2H2O = 60:16:4:20:1250 or S:TMTD:ZnO:BHT:SiO2 = 60:16:4:20:625. The optimum content of stabilizer powder was 0.9% (S/modified bitumen). The stabilizer was dry powder and can be directly put into bitumen. It can cross-link SBS and especially has an effect on preventing SBS segregation. The technical performance of SBS-modified bitumen with stabilizer powder, such as hot temperature performance, low temperature performance, anti-aging performance and thermal storage stability, all meet the relevant specifications.

Highlights

The traditional base bitumen suffers from several common defects such as temperature sensitivity, low temperature brittleness, easy flow at high temperature, poor anti-aging performance, low equivalent softening point and other shortcomings
Some experimental studies have been done by Amini et al [17], and the results show that using nano-composites can improve the storage stability at high temperature
Goli et al [18] studied the influence of carbon nanotubes on the storage stability of Styrene-Butadiene-StyreneBlock Copolymer (SBS)-modified bitumen binders, and the results showed that adding carbon nanotubes to the SBS-modified binder can improve the stability

Summary

Introduction

The traditional base bitumen suffers from several common defects such as temperature sensitivity, low temperature brittleness, easy flow at high temperature, poor anti-aging performance, low equivalent softening point and other shortcomings. These seriously affect the durability and service life of roads. Block Copolymer (SBS), Styrene-Butadiene-Rubber (SBR), Polyethylene (PE), Ethyl-Vinyl-Acetate (EVA) and other polymer modifiers were used to modify the base bitumen. Compared to linear SBS, radial SBS has better performance in improving thermal storage stability and low temperature ductility, but the defects in thermal storage stability of SBS-modified bitumen remain. This creates serious problems for the construction technicians and the performance advantages of SBS-modified asphalt pavement [6,7]

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Conclusion