Innovative Use of Sugarcane Bagasse Ash in Green Alkali-Activated Slag Material: Effects of Activator Concentration on the Blended Pastes

Alkali-activated slag material (AAS) is widely accepted as an alternative binder that can be used in place of Portland cement. The present study is aimed to assess fresh and hardened AAS pastes modified with sugarcane bagasse ash (SBA)—a combustion byproduct of sugarcane bagasse ash in sugar cane industries and to investigate effects of alkali-activated dosage (sodium hydroxide and sodium silicate) on properties of the slag/SBA-based system (slag/SBA mass ratio = 100/0, 90/10, 80/20, 70/30, 60/40). Testing results on fresh paste indicate that loss of workability occurs when increasing either activator concentrations (Ms\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${M}_{s}$$\end{document} = SiO2/Na2O and n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n$$\end{document} = %Na2O/binder) or SBA content. Moreover, increase in n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n$$\end{document} and Ms\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${M}_{s}$$\end{document}-values leads to considerably shorten the setting time. For hardened pastes, when increasing Na2O percentage (n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n$$\end{document}) from 6 to 8%, the compressive strength increases by 16% and 29% for specimens without and with 40% SBA, respectively; higher Ms\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${M}_{s}$$\end{document} performs a gradual increase in strength for specimens modified with up to 20% SBA. In addition, raising both n\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n$$\end{document} and Ms\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${M}_{s}$$\end{document} results in improving the sulfate attack resistance and lowering water absorption. It can be said that mix proportion of the alkali-activated slag-SBA mixtures could be achieved with balance of the fresh behavior, strength, and durability. Based on this aspect, alkali-activated mixtures containing 20% SBA (80/20) would be recommended.