Waste Glass Powder as a Circular-Economy Precursor in Geopolymer Binders.

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Growing demand for low-carbon, resource-efficient construction materials.
• Increasing interest in geopolymer binders utilizing industrial and post-consumer wastes.
• Waste glass powder (WGP) as a promising silica-rich precursor for alkali-activated systems.

Purpose of the Study:

• To synthesize knowledge on WGP reactivity, gel chemistry, and long-term performance.
• To apply a reaction-transport-ageing (R-T-A) framework for mechanistic understanding.
• To address inconsistencies in reported WGP durability trends.

Main Methods:

• Literature review and synthesis of existing research.
• Application of the R-T-A framework to link material properties and performance.
• Analysis of WGP dissolution, gel formation, and transport characteristics.

Main Results:

• WGP's amorphous structure facilitates silica release, influencing N-A-S-H gel formation.
• Reaction products dictate transport properties and ageing, impacting durability.
• Variability in results stems from mix design factors, not intrinsic WGP inconsistency.

Conclusions:

• The R-T-A framework clarifies how reaction, transport, and ageing influence durability outcomes.
• WGP has significant potential as a circular-economy precursor for alkali-activated binders.
• Reliable structural use necessitates durability-informed mix design and extended testing.