||Two types of polymer are generally used to modify bitumen for road construction: plastomers and elastomers. EVA (Ethene-Vinyl-Acetate) and PE (Polyethylene) are examples of commonly used plastomers. SBS (Styrene-Butadien-Styrene) is the most used elastomer. Basically, plastomers increase the viscosity and stiffness of the bitumen. Elastomers also improve the elastic behavior of the bitumen.