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% (C80FA20-xWGx: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.