Performance of SBR-Modified Emulsified Asphalt and Cold-Mixed Aggregate

Conventional emulsified asphalt has insufficient bonding strength and cannot meet the requirements for cold mixing and cold laying. Styrene-butadiene rubber (SBR) modified emulsified asphalt was prepared using a method that combines modification and emulsification, and the effect of SBR content on the physical properties of the evaporation residue was investigated. Dynamic shear rheology, asphalt bending creep stiffness, and Fourier transform infrared spectroscopy were used to investigate the residues of emulsified asphalt at different curing times and temperatures to determine the optimal curing method for emulsified asphalt. X-ray diffraction and fluorescence microscopy were used to study the interaction between cement and emulsified asphalt during curing. The results showed that, as SBR was continuously added, the penetration of the evaporation residue of emulsified asphalt decreased while the softening point and elongation increased. The high- and low-temperature rheological properties of the SBR emulsified asphalt residue obtained after curing at 110°C for 24 h were optimal. Infrared spectroscopy indicated that the sulfonyl index was lower for the residue cured at 110°C for 24 h. Fluorescence microscopy showed that the cement and emulsified asphalt were perfectly blended. The AC-16 graded SBR emulsified asphalt mixture exhibited good high-temperature stability and low-temperature crack resistance in rutting and low-temperature bending tests.