Publication detail

Doubts over capillary pressure theory in context with drying and autogenous shrinkage of alkali-activated materials

KALINA, L. BÍLEK, V. BARTONÍČKOVÁ, E. KALINA, M. HAJZLER, J. NOVOTNÝ, R.

Original Title

Doubts over capillary pressure theory in context with drying and autogenous shrinkage of alkali-activated materials

Type

journal article in Web of Science

Language

English

Original Abstract

One of the most important technological problems associated with alkali-activated materials is high shrinkage. In this study, shrinkage reducing admixtures (SRAs) based on amino alcohols were used in alkali-activated slag (AAS) as strong surfactants that should, in terms of capillary pressure theory, decrease shrinkage via the decrease in surface tension. Although the surface tension of the pore solution was reduced by SRAs, autogenous shrinkage was not affected in the long run, while drying shrinkage was noticeably reduced and simultaneous weight changes were dramatically increased. The expected retardation effect of SRAs on hydration was confirmed using isothermal calorimetry, strength development, mercury intrusion porosimetry and scanning electron microscopy. The obtained results suggest that the observed effect of SRAs on drying shrinkage was caused by coarser pore structure rather than by a decrease in surface tension of the pore solution. Since the decrease in surface tension does not necessarily lead to decrease in shrinkage, the application of capillary pressure theory in AAS can sometimes be an issue.

Keywords

Alkali-activated slag; Shrinkage; Admixture; Hydration; Capillary pressure; Surface tension

Authors

KALINA, L.; BÍLEK, V.; BARTONÍČKOVÁ, E.; KALINA, M.; HAJZLER, J.; NOVOTNÝ, R.

Released

10. 7. 2020

ISBN

0950-0618

Periodical

Construction and building materials

Year of study

248

Number

118620

State

United Kingdom of Great Britain and Northern Ireland

Pages from

1

Pages to

8

Pages count

8

URL

https://www.sciencedirect.com/science/article/pii/S0950061820306255

BibTex

@article{BUT162682,
  author="Lukáš {Kalina} and Vlastimil {Bílek} and Eva {Bartoníčková} and Michal {Kalina} and Jan {Hajzler} and Radoslav {Novotný}",
  title="Doubts over capillary pressure theory in context with drying and autogenous shrinkage of alkali-activated materials",
  journal="Construction and building materials",
  year="2020",
  volume="248",
  number="118620",
  pages="1--8",
  doi="10.1016/j.conbuildmat.2020.118620",
  issn="0950-0618",
  url="https://www.sciencedirect.com/science/article/pii/S0950061820306255"
}