Opportunities of Using Additive Manufacturing Waste Materials in Asphalt Concrete

Abstract: The rapid proliferation of additive manufacturing, also known as 3D printing, has revolutionized manufacturing, but it also generates significant environmental challenges, particularly in waste management. Research indicates that approximately 33% of all additive manufacturing materials, mainly polymers, result in waste, complicating disposal and recycling efforts. Innovative practices, such as using additive manufacturing waste in the production of asphalt concrete, are being explored to address these challenges. This approach integrates specific polymers based on their thermal properties, mixing methods, and physical forms to enhance the performance of asphalt concrete. Common additive manufacturing polymers include Polyethylene, Polypropylene, and Styrene-Butadiene-Styrene, which can be used in asphalt concrete by incorporating 2% to 8% by weight. These polymers would improve the elasticity, resistance to cracking and rutting, and overall durability of the asphalt, extending its service life. However, the integration of these polymers is not without challenges. Increased production costs, the necessity for specialized mixing equipment, and potential environmental impacts must be carefully considered. However, not all additive manufacturing polymers are suitable for use in asphalt concrete. Polymers such as Polyvinyl Chloride, Polystyrene, and certain thermoplastic elastomers can degrade material properties and compromise the integrity of the asphalt concrete due to the waste materials' low thermal stability, improper mixing characteristics, or unfavorable physical forms. Through a comprehensive review of polymer properties and their applications in road construction, the findings of this research seek to inform best practices for integrating additive manufacturing waste into asphalt concrete. This exploration promotes waste reduction and enhances the performance of asphalt concrete, contributing to a more sustainable future in construction.