Material properties of recycled PET composites for structural anchoring and other civil engineering applications

This paper evaluates the properties of recycled polyethylene terephthalate (rPET) from bottle waste flakes for producing non-conductive injection-moulded composites for construction, specifically anchors and connectors. The work addresses the growing need for sustainable materials in civil engineering by exploring a high-value application of 100% recycled PET combined with alkaline-resistant glass fibres, suitable for use in cementitious and alkaline environments. Mechanical tests were conducted on composites reinforced with 30, 40 and 50 wt% fibres. Addition of fibres improved flow characteristics, crystallisation kinetics, and facilitated demoulding of the parts, enhancing mechanical properties (tensile modulus up to ~ 19 GPa, flexural strength up to ~ 234 MPa, and Charpy impact strength up to ~ 31 kJ/m²) and achieving properties comparable to commercial virgin PET composites. The micromechanical analysis and SEM observations confirmed the high quality and homogeneity of the composites. The favourable properties and processing characteristics pave the way for the application of these materials in injection-moulded construction components, including anchors, which are currently under further investigation.