Influence of waste glass powder on printability and mechanical properties of 3D printing geopolymer concrete

Geopolymers represent a promising solution for reducing carbon emissions in 3D printing concrete (3DPC). This study explores the utilization of waste glass powder (WGP) as a novel precursor material to evaluate its influence on the printability and hardened mechanical properties of 3D printing geopolymer concrete based on slag and fly ash. Experimental results indicate that WGP content below 10% accelerates hydration and enhances buildability, whereas content exceeding 10% slows hydration but improves extrudability. Mechanical tests on cured specimens demonstrate a notable increase in compressive and flexural strength with increasing WGP content from 0% to 20%. Microstructural and chemical analyses of the 20% WGP variant reveal a denser morphology and an optimized Si/Al ratio.