Study on mechanical properties and microstructure of ultra-high performance concrete containing waste glass powder

To address the issues of excessive cement and energy consumption in ultra-high performance concrete (UHPC), waste glass powder (WGP) was utilized to replace cement at varying rates of 0%, 10%, 20%, and 30% to prepare UHPC. The results indicated that the incorporation of WGP influenced the flowability of UHPC, although it concurrently reduced its mechanical properties. When WGP was utilized at a specific replacement rate of 10%, it was found to enhance the mechanical properties during the later stages of curing (60 and 90 days). Notably, at a WGP replacement rate of 10%, the compressive strength and flexural strength at 90 days of curing reached peak values of 173.1 and 36.4 MPa, respectively. WGP exhibited effective micro-aggregate filling and pozzolanic effects; however, excessive replacement rates led to an increased Ca/Si ratio in the C-S-H gel, resulting in reduced structural compactness and compromised performance of UHPC.