No abstract

SBS (styrene-butadiene-styrene block copolymer) has been widely used in pavement industry as an asphalt modifier. Nanomaterials can further enhance the performance of SBS modified asphalt. However, rare studies investigate the feasibility of using graphene as a performance enhancer of SBS modified asphalt. To fill this gap, comprehensive experimental tests including chemical and mechanical test were carried out on SBS-graphene modified asphalt and SEBS (styrene-ethylene-butylene-styrene block copolymer, which is a hydrogenated polymer of SBS) modified asphalt. Graphene with different dimensions and contents was taken into consideration in this study. Based on the experimental work, it can be concluded that graphene improves the mid-temperature performance of SBS modified asphalt. Compared with two-dimensional graphene, three-dimensional graphene has a greater advantage and the enhancement effect increases with the increase of its dosage. In addition, the cross-linked structure of SBS-graphene composite improves the distribution of SBS in asphalt, which improves the overall performance of SBS modified asphalt.

Breaking waste tires into crumb and adding it to asphalt as modifier to prepare asphalt rubber (AR) is an effective method to solve the waste tire problem and improve the performance of matrix asphalt. The modified asphalt has better high and low temperature performance. However, the segregation of the crumb rubber modifier (CRM) causes storage instability of the AR. At present, studies have been conducted that improving the solubility of the CRM or adding some macromolecular polymer can improve the storage stability of the AR. However, the structure and polarity of the CRM surface are rarely explored for its correlation with the storage stability of AR. In this paper, the surface structure and polarity of the CRMs was changed by four different reagents, and the properties of the ARs prepared by the CRM were measured to analyze the adhesion between the CRM and the asphalt. It is concluded that the CRM with rough porous and non-polar surface has higher storage stability due to the better interfacial adhesion, which provides a research direction for improving the storage stability of rubber asphalt.