Performance Evaluation of Carboxylated Styrene-Butadiene Latex in Bitumen and in Asphalt Mixtures

Restricted by the harsh environmental conditions in cold regions, the construction of polymer-modified asphalt pavement in these areas is usually a process of high emissions of toxic and harmful gas and large energy consumption. To this end, carboxylated styrene-butadiene latex (XSB) was adopted as a novel modifier, and the mechanical performances of bitumen and asphalt mixture after modification were examined. Research shows that the use of XSB effectively absorbs polar components in bitumen and hinders the formation of bee-like structures, which is manifested by a reduction in the dimension of bee-like structures and microscopic roughness of modified bitumen. The application of XSB dramatically improves the performances of bitumen and asphalt mixture, including rutting, fatigue, low-temperature cracking, and moisture resistance, and the performances of asphalt mixtures after modification can meet the most stringent specification requirements in China when the mass ratio of the XSB reaches 6%. More importantly, compared to a polymer-modified asphalt mixture, the introduction of XSB notably enhances the performances of bitumen and asphalt mixture without increasing the construction temperature of the matrix asphalt mixture, which will significantly reduce energy consumption and lead to fewer toxic and harmful gas emissions. This study presents a potential sustainable solution for asphalt pavements in cold regions, promoting cleaner production while significantly enhancing pavement performance.