Evolution of room-cured alkali-activated silicomanganese fume-based green mortar designed using Taguchi method. (8th November 2021)

• Record Type: Journal Article
• Authors: Nasir, Muhammad; Johari, Megat Azmi Megat; Adesina, Adeyemi; Maslehuddin, Mohammed; Yusuf, Moruf Olalekan; Mijarsh, M.J.A.; Ibrahim, Mohammed; Najamuddin, Syed Khaja
• Is Part Of: Construction & building materials. Volume 307(2021)
• Publication Date: 2021-11-08
• Subjects: Alkali-activated mortar -- Industrial by-products -- Compressive strength -- Microstructure -- Taguchi method -- Response surface method; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.124970
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: SiMnF-based green AAMs were synthesized at room temperature. Composition of AAMs was designed using the Taguchi method. Numerical methods were employed to carry out various analysis of results. High strength was attained with GGBFS:SiMnF = 30:70, Na2 SiO3 /10MNaOH = 2.5, AAs/PMs = 0.5 and sand/PMs = 1.5. Optimum AAM exhibited dense microstructure attributed to embedment of major constituent elements. Abstract: This paper presents the results of a study conducted to synthesize alkali-activated mortars (AAMs) at room temperature. The AAMs were prepared using silicomanganese fume (SiMnF) and ground granulated blast furnace slag (GGBFS) as precursor materials (PMs) and sodium hydroxide (NaOH) and sodium silicate (Na2 SiO3 ) as alkaline activators (AAs). The composition of the AAMs was designed and optimized using the Taguchi method. Five factors with four levels each were investigated in this study, including the ratio of GGBFS to PMs (0–4.5), sand to PMs ratio (1.5–2.4), molarity of NaOH (4–10 M), Na2 SiO3 /NaOH ratio (2–3.5) and AAs to PMs ratio (1.5–2.4). Based on the orthogonal array proposed by the Taguchi method, 16 AAMs were cast with varying flow and unit weight to evaluate the compressive strength at 3, 7 and 28 days. The strength data was statistically analysed by employing ANOVA and response surface methods to investigate the effect of experimental variables. AAM with 30:70 proportion of GGBFS and SiMnF, Na2 SiO3 /10 MNaOH of 2.5, AAs/PMs ratio of 0.5 and sand to PMs ratio of 1.5 attained optimum strength. Based on the SEM and EDS analysis, the molar ratios among the major constituent elements intertwined in the cemented matrix were established which contributed to the formation of alkaline products and microstructural densification of the optimum mixture.