Use of Recycled Polyethylene in Asphalt Mixture

Abstract

Plastics and plastic products have become part of our lives extremely quickly. Although, they make our lives easier in many aspects, at the end of their useful life, especially thanks to the thoughtless actions of people, they are becoming a serious environmental problem. Even though the laws and legislation are still forcing limits of using the plastic products and thus prevent waste, the concept of plastic-free living is probably not going to be reached easily and quickly. Using the recycling technology, we can prepare the recycled material, which represents a new raw material resource. With the right choice of physical-chemical parameters of recycled materials and using a suitable reaction condition we can incorporate them into the asphalt mixtures. Since their introduction the polymer-modified asphalt mixtures have gained in importance during the second half of the twentieth century, and they now play a fundamental role in the field of road paving. Moreover, the use of recycled plastic in such a product will contribute to the technical and economic recovery of secondary raw materials. The use of various recycled material in paving industry is a common practice but needs further research work. Thus, this study aims to the incorporation of recycled plastics into asphalt mixture. The main objective of our work was to find a suitable recycled plastic, which with its physico-chemical and technical parameters is suitable for incorporation into the asphalt mixture. In our study the recycled low-density polyethylene granulate was used, taken from films and various packaging materials. Our preliminary laboratory experiments were based on the possibilities to prepare and characterized the asphalt mixtures containing recycled plastic at different percentage, i.e., 4 %, 6 %, 8 % and 10 % by weight of bitumen. The experimental tests performed in the study were bitumen content, intergranularity, maximum bulk density, water sensitivity and resistance to permanent deformations. The results showed that the mix containing 6 % by weight of recycled plastic has ideal properties and meets most of the criteria that have been set for asphalt mixes. A commercially available polymer of similar chemical composition to the recycled material was used as a reference sample.

Keywords

• low-density polyethylene
• recyclate
• asphalt mixture
• reaction conditions
• polymers