Recycling of organic light-emitting diode waste glass as a sustainable cementitious material in ultra-high-performance fiber-reinforced concrete

This study explores the recycling of organic light-emitting diode (OLED) waste glass powder as a sustainable cementitious substitute in ultra-high-performance fiber-reinforced concrete (UHPFRC). Incorporating OLED waste glass powder markedly enhanced the microstructural and mechanical performance, with the optimal mixture at a 30% replacement ratio (UP-30). The UP-30 mixture exhibited increases in tensile strength, strain capacity, and strain energy density by 15.7%, 29.6%, and 44.3%, respectively, compared with the control. These improvements stemmed from the pozzolanic reactivity of OLED waste glass, which facilitated additional calcium silicate hydrate (C-S-H) formation, refined pore structure, and improved fiber–matrix bonding. Crack analysis revealed a 19% reduction in maximum crack width and an increase in microcrack density, indicating superior ductility and crack control. Life cycle assessment confirmed significant environmental benefits, including 19.0% lower CO 2 emissions and 11.7% reduced embodied energy, underscoring the potential of OLED waste glass for circular, low-carbon UHPFRC production. • Incorporating 30% OLED glass powder enhanced UHPFRC tensile strength to 19.9 MPa. • The 30% OLED glass mix exhibited 29.6% higher tensile strain and 44.3% higher energy. • Pozzolanic OLED glass refined pore structure and strengthened fiber–matrix interface. • Maximum crack width decreased by 19% (to 109.9 μm) with more uniformly spaced cracks. • CO 2 emissions and embodied energy were reduced by 19.0% and 11.7%, respectively.