Simulation of thaumasite sulfate attack on Portland cement mixtures using synthesized cement phases

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F19%3A00496982" target="_blank" >RIV/68378297:_____/19:00496982 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1061/(ASCE)MT.1943-5533.0002612" target="_blank" >https://doi.org/10.1061/(ASCE)MT.1943-5533.0002612</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1061/(ASCE)MT.1943-5533.0002612" target="_blank" >10.1061/(ASCE)MT.1943-5533.0002612</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Simulation of thaumasite sulfate attack on Portland cement mixtures using synthesized cement phases

Popis výsledku v původním jazyce

In this work, a simulation of thaumasite sulfate attack on portland cement mixtures was performed, using synthesized cement phases. Three model systems containing C3S, C3A, and alkali sulfate (CaSO4, Na2SO4, and K2SO4, respectively) and a fourth one consisting of ettringite and C−S−H, were designed, and several mixtures were prepared. Ca(OH)2 and CaCO3 were optionally added. Specimens stored at 5°C and 20°C in an atmosphere saturated in water vapor for 75 months were investigated with X-ray diffraction analysis and scanning electron microscopy. Thaumasite formed in all samples without C3A at 5°C, and at 20°C when sulfates were derived from CaSO4. Solid solution of thaumasite and ettringitewas detected in samples incorporating C3A and CaSO4 or Na2SO4 at 5°C. This was also observed at 20°C when CaSO4 was the source of sulfates, whereas ettringite formed in the case of Na2SO4. The absence of thaumasite and ettringite in specimens containing C3A and K2SO4 was attributed to the alkali carbonation process. In the fourth system, decomposition of ettringite occurred in the specimens exempt of Ca(OH)2. The work is supposed to contribute to understanding the primary causes of concrete damage when the concrete is subjected to long-term sulfate attack.

Název v anglickém jazyce

Simulation of thaumasite sulfate attack on Portland cement mixtures using synthesized cement phases

Popis výsledku anglicky

In this work, a simulation of thaumasite sulfate attack on portland cement mixtures was performed, using synthesized cement phases. Three model systems containing C3S, C3A, and alkali sulfate (CaSO4, Na2SO4, and K2SO4, respectively) and a fourth one consisting of ettringite and C−S−H, were designed, and several mixtures were prepared. Ca(OH)2 and CaCO3 were optionally added. Specimens stored at 5°C and 20°C in an atmosphere saturated in water vapor for 75 months were investigated with X-ray diffraction analysis and scanning electron microscopy. Thaumasite formed in all samples without C3A at 5°C, and at 20°C when sulfates were derived from CaSO4. Solid solution of thaumasite and ettringitewas detected in samples incorporating C3A and CaSO4 or Na2SO4 at 5°C. This was also observed at 20°C when CaSO4 was the source of sulfates, whereas ettringite formed in the case of Na2SO4. The absence of thaumasite and ettringite in specimens containing C3A and K2SO4 was attributed to the alkali carbonation process. In the fourth system, decomposition of ettringite occurred in the specimens exempt of Ca(OH)2. The work is supposed to contribute to understanding the primary causes of concrete damage when the concrete is subjected to long-term sulfate attack.

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/LO1219" target="_blank" >LO1219: Udržitelný pokročilý rozvoj CET</a><br>

Návaznosti

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

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Journal of Materials in Civil Engineering

ISSN

0899-1561

e-ISSN

—

Svazek periodika

31

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

04018393

Kód UT WoS článku

000453216200036

EID výsledku v databázi Scopus

2-s2.0-85058236903