The styrene-butadiene-styrene (SBS) triblock copolymer was used to modify asphalt binder with sulfur employed as a dissolving agent. The morphology and engineering properties of the binders were investigated using transmission electron microscopy (TEM), rotational viscometry and dynamic shear rheometry. At low sulfur concentration, a continuous phase is present and the composite behaves like asphalt with moderately enhanced elastic response. Appearance of a dispersed structure usually begins at 3 to 5 per cent sulfur. At high sulfur concentrations micrographs from transmission electron microscopy illustrate the compatibility of SBS-modified asphalt. The rheological properties of SBS-modified asphalt depend strongly on the sulfur level. Increasing sulfur levels leads to an increase in the complex modulus ratio of modified to basic asphalt, and consequently the addition of sulfur improves on the engineering behavior of SBS-modified asphalt. The addition of sulfur significantly improves the storage stability of SBS-modified asphalt at high temperatures.(a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Samenvatting