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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F20%3APU135825" target="_blank" >RIV/00216305:26310/20:PU135825 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0950061820306255" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0950061820306255</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.conbuildmat.2020.118620" target="_blank" >10.1016/j.conbuildmat.2020.118620</a>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20102 - Construction engineering, Municipal and structural engineering

Projekt

<a href="/cs/project/GA17-03670S" target="_blank" >GA17-03670S: Vývoj přísad redukujících smrštění navržených pro alkalicky aktivované systémy</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Construction and building materials

ISSN

0950-0618

e-ISSN

1879-0526

Svazek periodika

248

Číslo periodika v rámci svazku

118620

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

8

Strana od-do

1-8

Kód UT WoS článku

000531081200025

EID výsledku v databázi Scopus

2-s2.0-85080996794