Enhancing performance and hydration of waste cathode ray tube glass-Portland cement systems via C-S-H seedings: A multi-scale investigation

The recycling of waste cathode ray tube (CRT) glass in cement-based materials is hindered by its low early age reactivity which limits mechanical performance and large-scale utilization. This study presents a novel strategy to overcome this limitation by incorporating C-S-H seedings into waste CRT glass-Portland cement (PC) systems. Through a multi scale investigation encompassing workability compressive strength hydration kinetics phase assemblage and pore structure we demonstrate that C-S-H seedings act as both nucleation sites and physical fillers significantly accelerating early age hydration and promoting later pozzolanic reactions. An optimal seeding content of 1.5 wt enhanced 1 d compressive strength by 50.0% compared to the control and even surpassed pure PC by 40.5%. Notably total porosity was reduced by up to 63.2% at 1 d and the critical pore diameter was substantially refined. These improvements are attributed to a dual stage mechanism involving early age nucleation seeding and pore filling followed by enhanced pozzolanic reaction of waste glass at later ages. This work provides a scalable and effective approach for valorizing waste CRT glass in sustainable cementitious materials with a carbon emission reduction of 11.17% compared to conventional PC. The findings also highlight the need for future research on long term durability and life cycle assessment to support practical deployment.