Negative effect of Zinc compounds on hydration kinetics of ordinary Portland cement

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F21%3APU137892" target="_blank" >RIV/00216305:26310/21:PU137892 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1757-899X/1039/1/012004" target="_blank" >https://iopscience.iop.org/article/10.1088/1757-899X/1039/1/012004</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1757-899X/1039/1/012004" target="_blank" >10.1088/1757-899X/1039/1/012004</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Negative effect of Zinc compounds on hydration kinetics of ordinary Portland cement

Popis výsledku v původním jazyce

Heavy metals have significant effect on cement hydration mechanism and kinetics. The recycling of waste materials leads to increase of content of heavy metals in various industrial products and visibly affects properties of the Portland cement. One of the heavy metals that has been known to drastically increase the setting time is Zinc. Zinc forms various hydroxyl species with calcium cations. Pore solution thus has lowered concentration of calcium which suppresses formation of portlandite. Due to insufficient concentration of calcium the formation of CSH gel and further hydration of clinker grains is inhibited The aim of this study is to quantify the negative effects of Zinc at different concentrations at ambient temperature of 20 °C. Isoperibolic calorimetry was used to measure the negative effects of zinc on hydration kinetics of ordinary Portland cement. Zinc was added to the cement in the form of two soluble salts of Zn(NO3)2 hydrate, ZnCl2 and a poorly soluble compound ZnO. The concentration of zinc added was chosen between 0.1 and 1 mass % of clinker. Significant retardation of cement hydration with increasing zinc content was proven.

Název v anglickém jazyce

Negative effect of Zinc compounds on hydration kinetics of ordinary Portland cement

Popis výsledku anglicky

Heavy metals have significant effect on cement hydration mechanism and kinetics. The recycling of waste materials leads to increase of content of heavy metals in various industrial products and visibly affects properties of the Portland cement. One of the heavy metals that has been known to drastically increase the setting time is Zinc. Zinc forms various hydroxyl species with calcium cations. Pore solution thus has lowered concentration of calcium which suppresses formation of portlandite. Due to insufficient concentration of calcium the formation of CSH gel and further hydration of clinker grains is inhibited The aim of this study is to quantify the negative effects of Zinc at different concentrations at ambient temperature of 20 °C. Isoperibolic calorimetry was used to measure the negative effects of zinc on hydration kinetics of ordinary Portland cement. Zinc was added to the cement in the form of two soluble salts of Zn(NO3)2 hydrate, ZnCl2 and a poorly soluble compound ZnO. The concentration of zinc added was chosen between 0.1 and 1 mass % of clinker. Significant retardation of cement hydration with increasing zinc content was proven.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název statě ve sborníku

International Conference Building Materials, Products and Technologies

ISBN

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ISSN

1757-8981

e-ISSN

—

Počet stran výsledku

9

Strana od-do

1-9

Název nakladatele

IOP Publishing

Místo vydání

neuveden

Místo konání akce

Telč

Datum konání akce

2. 6. 2020

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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