Asphalt rubber versus other modified bitumens



Asphalt rubber and rubberized asphalt samples were produced using various available, public recipes and their properties were compared to different laboratory and bitumen terminal / refinery produced linear and radial type of styrene-butadiene-styrene block copolymer (SBS), SBS-polyphosphoric acid (PPA), ethylene-vinyl-acetate (EVA) and Elvaloy modified bitumen.

The aging characteristic of asphalt rubbers was found to be always better than the unsaturated polymer contained modified binders, however the confidence range of standards testing methods showed higher variability due to inhomogeneity of the rubber modified binders. Asphalt rubber had the highest, while Elvaloy resulted the lowest viscosity at all tested temperatures. Elasticity of SBS modified bitumens were found to be the best, while cold performance were significantly improved by rubber modified binders due to the presence of crumb rubber particles.

It was found that an appropriately designed and manufactured asphalt rubber binder can replace SBS, SBS-PPA or EVA, Elvaloy modified bitumen. However it should be considered that the main objective is probably not this but to increase utilization of rubber modified bitumen versus common non-modified bitumen.


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