Strength and Microstructural Characteristics of Fly Ash–Waste Glass Powder Ternary Blended Concrete

To reduce the proliferation of greenhouse gases in the construction industry, ternary blended concrete comprising fly ash (FA) powder, waste glass (WG) powder, and ordinary Portland cement (OPC) was developed such that the WG to total binder varied from 0 to 20% at intervals of 5% (C₈₀FA_20-xWG_x:x = WG/(WG + FA + OPC)). The developed concrete was investigated for water absorption, workability, 28-day compressive strength, binder phases, bond characteristics, microstructure, and elemental composition of the concrete. The mixture proportions of C₈₀FA₁₅WG₅ and C₈₀FA₁₀WG₁₀ exhibited better consistency and water absorption than the OPC concrete (C₁₀₀FA₀WG₀). Furthermore, the 28 d strength of C₈₀FA₁₅WG₅ marginally outperformed those of C₈₀FA₁₀WG₁₀ and C₈₀FA₂₀WG₀. The sample with equal proportions of FA and WG (C₈₀FA₁₀G₁₀) was more amorphous owing to the disappearance of the hedenbergite phase (CaFeSi₂O₆) and conversion of tobermorite (CSH) to C-A-S-H. C₈₀FA₁₀WG₁₀ also exhibited better microstructural stability than FA + OPC concrete (C₈₀FA₂₀G₀), owing to the pore-filling of the microcracks within the matrix. Finally, higher Si/Ca, Ca/Al, and Si/Al ratios were recorded in C₈₀FA₁₀WG₁₀ than in the case of FA preponderating WG in ternary blending. Finally, structural concrete can be produced through the ternary blending of glass waste, fly ash, and OPC, thereby promoting the valorization of solid waste and a sustainable environment.