EFFECT OF WASTE GLASS POWDER ON FRESH AND MECHANICAL PROPERTIES OF GGBFS–FLY ASH BASED GEOPOLYMER PASTE

Abstract

The present study investigates the influence of waste glass powder (GP) on the fresh and mechanical properties of geopolymer paste containing Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash (FA). Waste glass powder was incorporated as partial replacement of GGBFS and combined GGBFS–FA systems at replacement levels of 5%, 10%, 15%, and 20%. A total of 180 geopolymer paste specimens were prepared and cured under ambient curing and elevated temperature curing conditions. Experimental investigations were conducted to evaluate flowability, initial setting time, and compressive strength characteristics of geopolymer paste.

The experimental results revealed that the incorporation of glass powder reduced the flowability of geopolymer paste from 165 mm for the control mix to 142 mm at 20% GP replacement because of increased fineness and enhanced reactivity of glass particles. Similarly, the initial setting time decreased from 72 minutes to 48 minutes with increasing glass powder content. However, significant improvement in compressive strength was observed with the addition of glass powder. The geopolymer paste containing 15% GP exhibited optimum performance with a 28-day compressive strength of 52.6 MPa under ambient curing and 58.4 MPa under elevated temperature curing, compared to 45.3 MPa and 50.1 MPa respectively for the control mix. The incorporation of glass powder enhanced the geopolymerization process and resulted in denser matrix formation with improved mechanical properties. The study concludes that waste glass powder can be effectively utilized as a sustainable supplementary precursor material in geopolymer paste, contributing to improved strength characteristics and sustainable construction practices through efficient waste utilization and reduction of environmental pollution.