Rheological properties, storage stability and morphology of CR/SBS composite modified asphalt by high-cured method. (30th December 2018)

• Record Type: Journal Article
• Authors: Qian, Chengduo; Fan, Weiyu; Liang, Ming; He, Ying; Ren, Shisong; Lv, Xiaobo; Nan, Guozhi; Luo, Hui
• Is Part Of: Construction & building materials. Volume 193(2018)
• Page Start: 312
• Page End: 322
• Publication Date: 2018-12-30
• Subjects: Modified asphalt -- Crumb rubber -- SBS copolymers -- Curing process -- Rheological property; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.10.158
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: A logistic model is proposed to quantitatively describe the curing process. High-cured method improves workability, storage stability and quality stability. Low asphaltenes and high saturates benefit CR degradation and storage stability. Rheology of CR/SBS modified asphalt by high-cured method is systematically studied. Interaction mechanism of CR/SBS modified asphalt by high-cured method is revealed. Abstract: To improve the workability and storage stability of crumb rubber (CR) modified asphalt, high-cured method was employed. Styrene-butadiene-styrene (SBS) copolymers were added to compensate the loss of properties in the curing process. The curing process of CR modified asphalt and influence of SBS content as well as asphalt composition on conventional properties, rheological properties, storage stability and morphology of CR/SBS composite modified asphalt were investigated, respectively. The results showed that the curing process with three stages can be quantitatively described by logistic fitting model, which improves the workability, storage stability and quality stability of modified asphalt. High-cured CR modified asphalt shows a great improvement in conventional and rheological properties compared with base asphalt. The addition of SBS enhances the properties of modified asphalt, but the extent of improvement is less obvious than CR. Based on the morphology, the strip-type rubber with large size disappears due to the degradation of CR, resulting in better storage stability of modified asphalt. Moreover, low asphaltenes and high saturates are favorable to the CR degradation and storage stability, while moderate asphaltenes and high aromatics are beneficial for achieving desired properties. As a conclusion, CR/SBS composite modification by high-cured method is a cost-effective approach to produce asphalt binder.