Strength and Microstructural Characteristics of Flyash-Waste Glass Powders Ternary Blended Concrete

Ternary blended concrete comprising flyash powder (FA), waste glass powder (WG) and ordinary Portland cement (OPC) were prepared such that the WG to total binder varied from 0-20% (C80FA20-xGx: x = WG/(WG+FA+OPC)) at the interval of 0.05. The developed concrete was investigated for absorption, workability, 28-day compressive strength, product (binder) phases, bond characteristics, microstructural and elemental composition. The synergy of the proportion of WG and FA (5-15% and 10-10℅) together with OPC (80℅) reduced the workability, enhanced 28-day water absorption and produced moderately high compressive strength (47-48 MPa) that was about 15% lower than that recorded in pure OPC concrete (57.2 MPa). The binder with balanced proportion of FA and WG (C80FA10G10) was found to be more amorphous with better microstructural stability than pure FA blended concrete (C80FA20G0) due to pore-filling of the microcracks. Disappearance of hedenbergite phase (CaFeSi2O6) was noted in the developed ternary binder while more alumina in FA noticeably induced conversion of tobermorite (CSH to C-A-S-H in ternary binder. Besides, Si/Ca, Ca/Al and Si/Al ratios were higher in WG-FA balanced ternary binder (C80FA10WG10) than when FA preponderated WG. Finally, using WG in synergy with FA could regulate absorption, consistency, amorphorsity and microstructure characteristics of FA-WG ternary binder.