# Performances of the Synergy of Silica Fume and Waste Glass Powder in Ternary Blended Concrete
## 4 Conclusions  
The use of environmental waste in concrete production is very important to improving the characteristics and cost efficiency of the resultant concrete on one hand, and to get rid of the solid waste culminating against public health on the other. This study has investigated the impact of the ternary blending of ordinary Portland cement (OPC), waste glass powder (WGP) and silica-fume (SF) powders on the fresh property, workability, strength, bond characteristics and microstructure of the concrete. The conclusions are the following:  
* Glass addition to silica-fume concrete synergistically enhances the workability of the concrete
* The blending of glass powder with silica fume in OPC concrete increased its water absorption due to the proliferation of interfacial transition zones, which arose from the size incompatibility between the silica fume, glass particle and OPC particles. Silica fume reduced the absorption of concrete owing to the microfilling effect, while WGP enhanced it due to shape angularity and its higher capillary action that enhances water molecule transfer to adjacent particles.
* The fresh or wet density of OPC concrete (C\({}_{100}\)G\({}_{0}\)S\({}_{0}\)) was found to be more than that of ternary blended (WGP, SF and OPC) concrete due to the higher relative density of cement (3.15) in comparison with WGP and SF.
* Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) revealed that the incorporation of WGP in synergy with blended SF concrete enhanced silicate reorganization, enhanced the product amorphousness and reduced hydroxyl-based compounds such as portlandite due to amorphous silica infusion.
* The addition of glass waste in blended silica-fume concrete caused heterogeneity in the microstructure and the proliferation of weak interfacial transition zones, leading to the formation of microcracks in the morphology as noted in the scanning electronic microscope and energy dispersive spectroscopy (SEM/EDS) results.
* Economic and cost-efficient ternary blended concrete with a 28-day compressive strength beyond 40 MPa can be produced if the WGP is partly and synergistically substituted for SF such that the percentages of glass waste and silica fume are kept within 2.5-5% and 5-7.5%, respectively.  
Conceptualization, M.O.Y.; Formal analysis, M.O.Y. and A.O.B.; Funding acquisition, M.O.Y.; Investigation, M.M.H.A.-T. and A.K.U.; Methodology, M.O.Y., A.A.A. and I.M.; Project administration, A.A.A.; Supervision, M.O.Y. and A.H.A.; Writing--original draft, M.O.Y.; Writing--review & editing, K.A.A.A.-S. All authors have read and agreed to the published version of the manuscript.  
The authors extend their appreciation to the Deanship for Research & Innovation, Ministry of Education in Saudi Arabia for funding this research work through the project No: IFP-A-2022-2-1-10.  
Not applicable.  
All authors consent to the publication.  
The authors would like to appreciate the remarks of the anonymous reviewers which have greatly improved the manuscript. The continuous support of University of Haft Al Batin is appreciated.  
The authors declare no conflict of interest.