Polymer-modified Bitumen from the Wastes of Petrochemical Plants

Waste management is a major concern in petrochemical plants. Almost all types of wastes are used to modify bitumen. Following this concept polymer and non-polymer wastes of petrochemical production lines were used to modify bitumen. It was found that incorporation of the wastes separately or as a combination of some high performing polymer-modified bitumens are obtained. Almost all modifiers did not improve the low temperature properties of the modified bitumen and in some cases deteriorated this property. The low molecular weight polyethylene (LMP) and N-methylpyrrolidone (NMP) wastes increase high temperature performance of bitumen, whereas styrene-butadiene rubber (SBR) waste improves low temperature performance at moderate concentrations. The best performance grades (PG) obtained by introducing these modifiers are PG = 106-10, PG = 76-22 and PG = 94-16 at a rate of 5% modification, respectively. The best performance grades obtained with mixtures of NMP and SBR were PG = 82-16 and PG = 76-22. The most useful performance grades resulted form incorporation of mixtures of LMP and SBR in bitumen were PG = 94-16 and PG = 100-10. In fact, mixtures of LMP and SBR wastes were found to be the most beneficial compositions for bitumen modification.