Binding gel characterization of alkali-activated binders based on palm oil fuel ash (POFA) and fly ash. Issue 1 (2nd January 2018)

• Record Type: Journal Article
• Authors: Nadziri, Nurulhuda; Ismail, Idawati; Hamdan, Sinin
• Is Part Of: Journal of sustainable cement-based materials. Volume 7:Issue 1(2018)
• Page Start: 1
• Page End: 14
• Publication Date: 2018-01-02
• Subjects: geopolymer -- alkali-activated binder -- palm oil fuel ash -- fly ash; Cement -- Periodicals; Cement composites -- Periodicals; Cement; Cement composites; Periodicals; 620.135
• DOI: 10.1080/21650373.2017.1299054
• Languages: English
• ISSNs: 2165-0373

Abstract

Abstract : Pastes of palm oil fuel ash (POFA) and fly ash geopolymer activated with sodium hydroxide (NaOH) and combination of NaOH with sodium silicate (Na2 SiO3 ) were prepared and cured at 80 °C for a duration of 7, 28, and 90 days. The hydrated binding gel products were studied on phase, morphology, and bonding characterization. From these analyses, calcium–sodium–silicate–hydrate (C/N–S–H) gel type appear to form in sole POFA binder but at a very low Ca/Si ratio, while sole fly ash geopolymer binder consists of sodium–alumina–silicate–hydrate (N–A–S–H) binding gel product with a significant Na/Si ratio, regardless of activator types. When both precursors were used, a combination of both gel types was formed, however, Fourier transform infrared spectroscopy and energy-dispersive X-ray analyses show that the N–A–S–H gel is a more dominant product in the binder compared to the C/N–S–H gel.