An Empirical Model for Geopolymer Reactions Involving Fly Ash and GGBS
description: Numerous works are reported in literature regarding the enhancement of compressive strength of fly ash-GGBS geopolymer combinations with addition of alkali activators of varying concentrations. However, a limited study has been chronicled, revealing the specific role of alkali or alkaline earth contributed by the fly ash-GGBS combinations on the compressive strength development. It is well known that the strength of a geopolymer is dependent on gel formation from Al/Si ratio, Ca/Si ratio, and Ca/(Si + Al) ratio but their exact role when cured for various extended periods is unknown as yet. In the present study, alkali concentration in a fly ash-GGBS geopolymer combination was varied from 6 M to 12 M with increments of two mol in six different fly ash-GGBS combinations with a minimum of 20 percent and a maximum of 70 percent GGBS. The correlation coefficients between compressive strength and Al/Si, Ca/Si, and Ca/(Si + Al) ratios exhibited values higher than 0.95 taken individually. Multiple linear regression analysis with compressive strength (as dependent parameter) and individual values of Al/Si, Ca/Si, and Ca/(Si + Al) ratios (as independent parameters) was effectuated. It was observed that, depending on the composition, the compressive strength circumstantiated a changeover from Ca/Si to Ca/(Si + Al) ratio in the intermediate composition range. Such a detailed analysis is considered supportive of developing a suitable composition which will provide the optimum compressive strength of the combination. 2022 Beulah M et al.
creator: Beulah M.; Sudhir M.R.; Chen S.; Rai S.; Jain D.
source: Advances in Materials Science and Engineering, Vol-2022
publisher: Hindawi Limited
date: 2022-01-01
rights: All Open Access; Gold Open Access
relation: ISSN: 16878434
format: Online
language: English
type: Article
coverage: Beulah M., Department of Civil Engineering, School of Engineering and Technology, CHRIST, Deemed to Be University, Karnataka, Bangalore, India; Sudhir M.R., Department of Civil Engineering, School of Engineering and Technology, CHRIST, Deemed to Be University, Karnataka, Bangalore, India; Chen S., Civil and Environmental Engineering, University of North Carolina, Charlotte, 28223, NC, United States; Rai S., Department of Civil Engineering, School of Engineering, KS School of Engineering and Management, Karnataka, Bangalore, India; Jain D., Department of Construction Technology and Management, Bule Hora University, Blue Hora, Ethiopia