Effects of waste plastics as partial fine-aggregate replacement for reinforced low-carbon concrete pavements

• Published in: International journal of sustainable engineering Vol. 15; no. 1; pp. 192 - 207
• Main Authors: Tota-Maharaj, Kiran, Adeleke, Blessing Oluwaseun, Nounu, Ghassan
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 31.12.2022; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Aggregates; Building codes; Carbon; Compressive strength; Concrete aggregates; Concrete pavements; Dredging; Environmental engineering; Feasibility; fine aggregate; low carbon cementitious materials; Mechanical properties; Physical properties; Plastic debris; Plastics; Polymeric materials; Reinforced concrete; reinforced concrete pavements (RCP); Reinforcing steels; sustainable infrastructure; waste plastics; Waste utilization; Workability
• ISSN: 1939-7038; 1939-7046
• DOI: 10.1080/19397038.2022.2108156

Using waste plastics as a partial natural aggregate replacement and monitoring strength and workability reduction in pavement structures is vital to net-carbon zero. This study explores the utilisation of waste plastic as a fine aggregate replacement in medium-strength reinforced concrete pavements, for improving plastic aggregate performance and the intrinsic reasoning for observed strength performance. Various weight fractions of fines were substituted by the same weight of plastic aggregates ranging from 5-15% according to the appropriate standards (Eurocodes and British Standards). The physical and mechanical properties of the composites were analysed. The results indicated that the use of polymeric materials as a partial replacement for fines contributed to a decrease in workability, compressive strength and push-out bond between steel reinforcement and concrete. Despite these trends, 5% replacement of fine aggregates with plastic waste surpassed all the feasibility criteria. Furthermore, using 10% of plastic replacement by weight was deemed feasible in non-structural applications such as roads, pavements, and facades. The outputs have demonstrated environmental engineering concepts in tackling plastic waste, providing an alternative to conventional aggregate. Environmental benefits can arise due to the removal of potentially hazardous plastics from entering ecosystems as well as minimising dredging of global sand reserves.