Research on the Performance and Mechanism of SBS Latex–Modified Emulsified Asphalt

Different modifier dosages affect the performance of emulsified asphalt. In order to analyze the action of styrene-butadiene-styrene (SBS) latex dosing on the performance of emulsified asphalt and emulsified asphalt microsurfacing mixtures, this paper investigates the conventional properties, rheological properties, adhesion properties, and microscopic phase structure of emulsified asphalt modified with SBS latex of various dosages and the abrasion and rutting resistance of its emulsified asphalt mixtures. The results led to the following findings. The softening point and ductility of modified emulsified asphalt are enhanced, and the penetration decreased with the increase of SBS latex. The emulsified asphalt has enhanced low-temperature properties and exhibits excellent thermal stability. The addition of SBS latex caused the emulsified asphalt complex shear modulus and rutting factor values to increase and caused the phase angle to decrease. The rheological properties of modified emulsified asphalt also were improved. A stable three-dimensional structure was formed when SBS latex dosage was 8%. Digitized fluorescence images show a good correlation of the SBS with emulsified asphalt. The addition of SBS latex caused the emulsified asphalt thermal stability to be enhanced. The SBS latex caused a physical modification in the emulsified asphalt. The SBS latex also enhanced the viscoelastic properties of the emulsified asphalt, as confirmed using an atomic force microscopy test. The 1-h wet wheel abrasion value, width deformation rate, and rutting depth rate of the 8% SBS-emulsified asphalt were reduced by 77.7%, 91.6%, and 48.7%, respectively, compared with that of matrix asphalt. The optimum dosage of SBS latex was 8%.