High and Low Temperature Performance and Fatigue Properties of Silica Fume/SBS Compound Modified Asphalt.

Wenyuan Xu,Xuewen Zheng,Kai Cao,Huimin Feng

doi:10.3390/ma13194446

Wenyuan Xu, Xuewen Zheng + Show 2 more

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https://doi.org/10.3390/ma13194446

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Abstract

In order to study the high and low temperature properties, and fatigue properties, of silica fume/SBS (Styrene-Butadiene-Styrene) compound modified asphalt (SFSCMA), dynamic shear rheometer (DSR) and bending beam rheometer (BBR) are used to study matrix asphalt (MA), silica fume modified asphalt (SFMA) (silica fume (SF) 6%), SBS modified asphalt (SBSMA) (mass ratio of SBS to Matrix asphalt 4%), and silica fume/SBS compound modified asphalt, and the high temperature rheological properties of silica fume/SBS compound modified asphalt with different silica fume additions are also studied. The modification mechanism of SFSCMA was studied by scanning electron microscope (SEM). The investigation results turn out: along with the increase in the content of SF, the high temperature performance of SFSCMA is improved significantly. When the content of SF is 6%, the high temperature performance is the best. When the content of SF is more than 6%, the high temperature property of SFSCMA is lower than that of SBSMA. It is suggested to choose 6% as the content of SF. Compared with MA, SFMA, and SBSMA, SFSCMA has excellent high temperature performance; compared with MA and SFMA, the low temperature performance of SFSCMA is improved, but it is worse than that of SBSMA. Moreover, when the temperature is lower than −30 °C, its low temperature performance is close to that of MA, or even worse than that of MA. After the compound modification of SF and SBSMA, the fatigue properties of the asphalt are improved, and the fatigue performance of SFSCMA is the best among the four kinds of asphalt. There is a cross-linking force in the network structure of SFSCMA, which restrains the flow of the whole system, so that the stability of the compound modified asphalt is significantly improved, which is favorable to the high temperature performance and fatigue resistance of the compound modified asphalt. However, due to its low mobility, it has a negative impact on the low temperature performance of the compound modified asphalt. In addition, according to previous studies, compared with diatomite, it is proven that SF can reach the same level as diatomite in improving the high temperature performance and fatigue performance of asphalt. Therefore, SF can be used as a good choice of asphalt modifier and can achieve the purpose of waste recycling and environmental protection.

Highlights

Silica fume (SF) is an industrial dust produced from ferrosilicon or metal silicon
In the temperature range of 66–68 ◦ C, the curve of 6% and 8% silica fume (SF) content appears at the intersection, when the temperature is lower than the intersection temperature, the complex shear modulus G* and factor (G* /sinδ) of 8% SF compound modified bitumen are slightly higher than those of 6% compound modified asphalt; the complex shear modulus G* and factor (G* /sinδ) of 8% SF compound modified asphalt are slightly smaller than those of 6% compound modified asphalt when the temperature is higher than the intersection temperature
When the content of silica fume is more than 6%, the high temperature property of SFSCMA is inferior than that of Styrene butadiene styrene block copolymer (SBS) modified asphalt (SBSMA); combined with the previous research and the research in this paper, the silica fume (SF) content of 6% is recommended

Summary

Introduction

Silica fume (SF) is an industrial dust produced from ferrosilicon or metal silicon. It has the advantages of chemical corrosion resistance; good thermal stability and dimensional stability, excellent mechanical and electrical properties, and reinforcement. Materials 2020, 13, 4446 in building, chemical, metallurgical, and other industries. It can be used as cement or concrete admixture to improve the performance of cement or concrete, and mixing special concrete and compound cement with high strength, wear resistance, erosion resistance, corrosion resistance, permeability resistance, frost resistance and early strength, it has been well used in water conservancy, harbor wharfs, highways, airport runways, tunnels, and other fields. Because of its unique microporous structure and better adsorption capacity, it has been used as a modifier to make modified asphalt

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