Carboxylated styrene-butadiene latex (XSB) in asphalt modification towards cleaner production and enhanced performance of pavement in cold regions

The construction of flexible pavement in cold regions has always been a high-energy consumption process accompanied by the emission of a great deal of poisonous and pernicious gases and greenhouse gases (GhG), which results in significant harm to the workers’ health and aggravates environmental pollution. To solve the problem, a novel modifier of asphalt, carboxylated styrene-butadiene latex (XSB) was proposed, with excellent high-temperature and low-temperature performances. For this purpose, XSB modified asphalts with four different XSB contents were investigated in terms of the rheological properties, low-temperature properties, and modification mechanism. We found that the introduction of XSB notably enhanced the mechanical properties of asphalt, including viscosity, rutting resistance, creep and recovery behaviour, fatigue resistance and low-temperature cracking performance. These improvements can be put down to the fact that the surface of XSB particles is full of tiny folds and voids with large specific surface areas, which can absorb the light components and restrict the movement of small molecules in asphalt. While maintaining excellent engineering performances of asphalt, the above XSB modifier can also reduce the production temperature of modified asphalt by 30 °C–50 °C, which provides a cleaner solution with low energy consumption and low pernicious gas and GhG emission for the environmental challenges faced by flexible pavement in cold regions, and possess a broader application prospect.