Thermal, Mechanical and Microstructural Analysis of Metakaolin Based Geopolymers

In the present work, geopolymer matrices were developed by alkali activation of metakaolin, using NaOH and sodium silicate as activators. The samples of metakaolin and matrices were studied by thermal analysis (TGA/DTA) at temperatures between 22°C and 1000°C in a nitrogen atmosphere with a heating...

Full description

Saved in:

Bibliographic Details
Published in:	Materials research (São Carlos, São Paulo, Brazil) Vol. 22; no. 2
Main Authors:	Caballero, Liuski Roger, Paiva, Maria das Dores Macedo, Fairbairn, Eduardo de Moraes Rego, Toledo Filho, Romildo Dias
Format:	Journal Article
Language:	English
Published:	ABM, ABC, ABPol 01-01-2019 Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
Subjects:	ENGINEERING, CHEMICAL geopolymers MATERIALS SCIENCE, MULTIDISCIPLINARY mechanical performance metakaolin METALLURGY & METALLURGICAL ENGINEERING microstructural analysis thermal analysis microstructural analysis metakaolin geopolymers thermal analysis mechanical performance
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	In the present work, geopolymer matrices were developed by alkali activation of metakaolin, using NaOH and sodium silicate as activators. The samples of metakaolin and matrices were studied by thermal analysis (TGA/DTA) at temperatures between 22°C and 1000°C in a nitrogen atmosphere with a heating rate of 10°C/min. The analyses showed gradual mass losses for MK1 and MK2, occurring in the temperature range of 350-700°C, associated with the dehydroxylation of the kaolinite present in the metakaolin samples, when transforming into reactive metakaolin. Thermal analysis allowed to identify mass losses associated with the different events that occurred during the formation of the geopolymer structure. The formation of amorphous geopolymer networks was confirmed by the XRD and FTIR techniques. The quantitative analysis of XRD results by using the Rietveld method allowed determine the amorphous and crystalline content of the precursors and geopolymers. The results obtained, after analyzing the matrices, showed that the geopolymers obtained presented a mechanical performance comparable to systems found in the literature, with uniaxial compressive strengths ranging from 38-50 MPa and stiffness around 7 GPa. Hence, these systems are suitable for their future use as alternative binder materials for the production of mortars and concretes.
ISSN:	1516-1439 1980-5373 1980-5373
DOI:	10.1590/1980-5373-mr-2018-0716