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Carbonation resistance of alkali-activated GGBFS/calcined clay concrete under natural and accelerated conditions

Tambara, Luís U. D., Jr.; Hirsch, Astrid 1; Dehn, Frank 1; Gluth, Gregor J. G.
1 Institut für Massivbau und Baustofftechnik (IMB), Karlsruher Institut für Technologie (KIT)

Abstract:

The carbonation resistance of alkali-activated materials (AAMs) is a crucial parameter for their applicability in concrete construction, yet the parameters influencing it are insufficiently understood to date. In the present study, the carbonation resistance of alkali-activated concretes with varying fractions of ground granulated blast furnace slag (GGBFS) and calcined clay (i.e., high, intermediate, and low Ca contents) were assessed under natural and accelerated conditions. Corresponding hardened AAM pastes were studied using X-ray diffraction, thermogravimetry, Raman microscopy, and mercury intrusion porosimetry. The carbonation resistance of the concretes at natural CO2 concentration depended principally on their water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio. The remaining variability for similar ratios was caused by differences between the pore structures of the AAMs. For concrete with favorable water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio and pore structure, the carbonation resistance was comparable to that of Portland cement concrete. The relationship between carbonation coefficients obtained under accelerated and natural conditions differed for concretes with high and low fractions of calcined clay, indicating that accelerated carbonation testing is less suitable to study the carbonation of low-Ca AAMs.


Verlagsausgabe §
DOI: 10.5445/IR/1000175751
Veröffentlicht am 29.10.2024
Originalveröffentlichung
DOI: 10.1016/j.conbuildmat.2024.138351
Scopus
Zitationen: 1
Dimensions
Zitationen: 1
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Massivbau und Baustofftechnik (IMB)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 10.2024
Sprache Englisch
Identifikator ISSN: 0950-0618
KITopen-ID: 1000175751
Erschienen in Construction and Building Materials
Verlag Elsevier
Band 449
Seiten Art.-Nr.: 138351
Nachgewiesen in Web of Science
Scopus
Dimensions
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