<p>This paper investigates the feasibility of using waste glass powder as a partial replacement for cement in concrete, exceeding the current observed limit of ~ 20%. The study examines the chemical reactions between glass powder and cement to explore the likely factors that may restrict the replacement percentage to this threshold. Using mole-concept theory-based analysis, the findings suggest that additional calcium-silicate-hydrate (<i>C-S–H</i>) may be formed from the reactions between glass powder and Portlandite. This indicates the potential for cement replacement percentages greater than 20% without compromising the strength of the concrete, contrasting with the current experimentally observed limit. The paper identifies four potential key factors that may be responsible for the limited cement replacement: (1) at higher cement replacement percentage, there is unreacted glass powder in the mix; (2) the contribution to the strength of the <i>C-S–H</i> formed from the chemical reactions involving the glass powder is inferior to that from cement hydration; (3) size of the glass particles that hamper full expected chemical reactions; and (4) the slow rate of the chemical reactions, and hence the strength gain may not happen within 28&#xa0;days. Finally, the paper discusses possible means of overcoming the above limitations towards achieving high glass powder percentages as cement replacement in concrete. The effect of high glass powder content on the fresh, mechanical and durability properties of concrete is beyond the scope of this study. Instead, the focus is on exploring potential methods to overcome the challenges associated with its use, aiming to reduce the carbon footprint.</p>