The Compatibility of SBS-Modified Asphalt

Compatibilities of six kinds of base asphalts with styrene-butadiene-styrene (SBS) were evaluated by difference of isolation softening points and intrinsic viscosities of six SBS-modified asphalts. By comparing four-component distribution of six kinds of base asphalts with compatibility evaluation results of SBS modified asphalt, ratio of saturates to aromatics was selected as the main reference. Three base asphalts were mixed with saturates-rich refined oil and aromatics-rich extract oil by furfural according to a reasonable ratio of saturates to aromatics, and compatibility of the three kinds of mixed asphalt with SBS was evaluated. Results show that an isolation experiment combined with intrinsic viscosity can be used to evaluate compatibility of SBS-modified asphalt effectively. colloidal instability index (CI) (saturates + asphaltenes)/(aromatics + resins), content of light components (saturates + aromatics) and ratio of saturates to aromatics all have an influence on compatibility of SBS-modified asphalt, but none is a sufficient condition for determining compatibility of SBS-modified asphalt. Reasonable distribution of four components is a key factor for achieving optimum compatibility. It is proposed that components distribution of a base asphalt that has optimal good compatibility with SBS is CI of about 0.3, content of light components more than 55 wt%, and ratio of saturates to aromatics between 0.42 and 0.55.