Detail publikačního výsledku

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.

Originální název

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

Anglický název

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

Druh

Článek WoS

Originální abstrakt

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.

Anglický abstrakt

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.

Klíčová slova

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

Klíčová slova v angličtině

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

Autoři

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

Rok RIV

2021

Vydáno

10.07.2020

ISSN

0950-0618

Periodikum

Construction and Building Materials

Svazek

248

Číslo

118620

Stát

Spojené království Velké Británie a Severního Irska

Strany od

1

Strany do

8

Strany počet

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"
}