Probe the properties of SBS/CR composite modified asphalt with CR directional distribution

With the aim of studying the properties of SBS/CR modified asphalt with CR directional distributed in SBS, SBS/CR composites were prepared in advance by method of melt blending in this work, and then the SBS/CR composite modified asphalts were prepared by the traditional wet process. The effect of the content of CR and the compatibility between SBS and CR on modified asphalts were discussed in details. The results show that the increasing blending temperature is conducive to improving the compatibility between SBS and CR, but it led to degradation of polymer modifiers. The hot storage stability of modified asphalt decreases with the growth content of CR, while increases with the increasing blending temperature. The conventional properties, elastoplastic relaxation behavior, temperature-sensitivity and rheological behaviors of modified asphalts were evaluated by the test of cyclic tension, rotational viscosity, dynamic shear rheometer (DSR) and blending beam rheometer (BBR). The results indicate that SBS combined with CR in advance have positive effect on the properties of modified asphalt, which is related to the directional distribution of CR and the improved compatibility between SBS and CR. Furthermore, the pre-blending of CR with SBS enhances the resistance of modified asphalts to thermal-oxidation aging. This work provides further guidance for understanding the modification mechanism of SBS/CR composite modified asphalt and improving the properties of SBS/CR modified asphalt. •SBS/CR modified asphalt with CR selective distribution were prepared.•The distribution state of CR has impact on the properties of modified asphalt.•The pre-combined SBS and CR can improve the storage stability of modified asphalt.•The better compatibility between SBS and CR, the better performance of modified asphalt.