The influence of fly ash characteristics and reaction conditions on strength and structure of geopolymers. (30th September 2015)

• Record Type: Journal Article
• Authors: Nikolić, Violeta; Komljenović, Miroslav; Baščarević, Zvezdana; Marjanović, Nataša; Miladinović, Zoran; Petrović, Rada
• Is Part Of: Construction & building materials. Volume 94(2015)
• Page Start: 361
• Page End: 370
• Publication Date: 2015-09-30
• Subjects: Fly ash -- Reactivity -- Geopolymer -- Compressive strength; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2015.07.014
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Effects of FA characteristics and reaction conditions on geopolymer strength were studied. Development of FA-geopolymer structure was studied using SEM/EDS and NMR analyses. The correlation of FA characteristics, structure and strength of geopolymer was given. Strength of geopolymers was correlated with a fraction of Al-rich structural units. Rapid test for assessment of FA reactivity was evaluated. Abstract: Reactivity of Class F fly ash (FA), development of strength, and structure of FA-based geopolymers, depending on the reaction conditions, were examined in this paper. The results of SEM/EDS and NMR analyses revealed that the composition of aluminosilicate gel changed during reaction, i.e. Si/Al atomic ratio decreased with the reaction time. Higher strength of geopolymers was associated with a higher fraction of aluminum rich structural units, higher crosslinking, and more compact structure. A rapid test for the assessment of FA reactivity and thus the applicability of FA for geopolymer synthesis was proposed.