Modification of Asphalt Binder with Waste Expanded Polystyrene (EPS) Foam

Abstract

Waste polymers are widely used in asphalt modification, especially, in order to reduce their detrimental effect on the environment. This study discusses the usability of waste expanded polystyrene (EPS) foam in asphalt modification. In this respect, the EPS foam, which produces waste in both production and use stages, was mixed with bitumen by weight at the ratios of 2%, 4%, 6%, and 8%, and dry modification method was employed. The penetration, ductility, softening point, flash point, and specific gravity values of virgin bitumen were compared with waste EPS foam modified bitumen. The comparison was made by both graphical and statistical methods. A strong correlation between the physical properties of modified asphalt and the ratio of EPS foam was observed. A drop was observed in penetration and ductility values. Besides, it was found by statistical analyses that 2% of the increase in the additive ratio is not sufficient to make a significant difference in the physical properties of bitumen, therefore, the increase should be at least 4%. Overall, it is concluded that EPS foam additive can be used in bitumen modification for hot regions where low penetration is required.