Upcycling of plastic and tire waste toward use as modifier for asphalt binder

A tremendous amount of plastic and tire waste is generated every day. Pyrolysis gives a sustainable plastic and tire waste management solution by transforming them into high-value carbonaceous materials (i.e., char). Char made from plastic or tire waste can be used as a modifier for asphalt binder (i.e., bitumen), in order to improve the properties and performance of base bitumen. In most cases, the char is produced from waste feedstock at ≤300°C, most likely due to the high volatile matter content in feedstock. These chars have been proven experimentally to enhance the deformation resistance, rutting resistance, stiffness, and elasticity of bitumen. The optimal dosage of char in the modification process is highly associated with the kind of waste feedstock and pyrolysis conditions under which the char is made. The present review highlights the promise of the char materials derived from plastic and tire waste for use in materials applied to civil and construction industries, which is aimed specifically at expanding the application of chars made from plastic and tire waste beyond their typical applications, such as in environmental remediation and catalysts.