Improvement effect of different modifiers on storage stability of high content SBS modified asphalt

High content Styrene-butadiene-styrene (SBS) modified asphalt binder is commonly used for permeable pavements attribute to reasonable adhesion ability, deformation resistance and toughness. However, due to the large difference in molecular weight between styrene-butadiene-styrene block copolymer and asphalt, the compatibility between SBS and asphalt has always been a key issue restricting its development. To improve the compatibility of high content SBS modified asphalt, the preparation process of high content SBS modified asphalt (shear time, temperature, rate, modifier content) was investigated by orthogonal experimental design method. The effects of modifiers (polyphosphoric acid, montmorillonite, and sulfur) on the physical properties and compatibility of high content SBS modified asphalt were investigated by physical property tests, storage stability tests and dynamic shear rheology tests. The results shows that all three additives have improved the storage stability of high content SBS-modified asphalt, among which, nano montmorillonite has the best comprehensive improvement effect. In addition, the preparation process of high content SBS modified asphalt will also affect its physical properties and compatibility. When the content of MMT and SBS is 2% and 8% respectively, the shear temperature is 170 °C, the shear rate is 4000 rpm, and the shear time is 150 min, the high and low temperature performance of high content SBS modified asphalt is good and the compatibility is the best.