Impact of Zn salts on hydration, compressive strength, microstructure, leachability and toxicity of ordinary Portland cement

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F14%3APU112781" target="_blank" >RIV/00216305:26310/14:PU112781 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Impact of Zn salts on hydration, compressive strength, microstructure, leachability and toxicity of ordinary Portland cement

Popis výsledku v původním jazyce

Ordinary Portland cement (OPC) has been used to solidify of hazardous waste for about 25 years and the effect of waste components on the hydraulic activity is an interesting object for the research. The possible increase of zinc incorporation present insecondary raw materials may lead to changes in behavior of pastes made from OPC. In this study zinc nitrate, chloride and oxide were added to Portland cement. The concentrations of 0.05, 0.1, 0.5 and 1.0 weight percent of zinc in cement were tested. After 1, 7, 28 and 90 days were measured the compressive and flexural strengths. The addition of salts of zinc modifies resulted compressive strength in various ways. The early compressive strength (1 day) decreases in comparison with the reference sample. This difference is probably due to a delay in tricalcium silicate hydration as shown by isothermal and isoperibolic calorimetry. As shown by scanning electron microscopy and X-ray diffraction, zinc is predominantly absorbed in CaZn2(OH)6.2

Název v anglickém jazyce

Impact of Zn salts on hydration, compressive strength, microstructure, leachability and toxicity of ordinary Portland cement

Popis výsledku anglicky

Ordinary Portland cement (OPC) has been used to solidify of hazardous waste for about 25 years and the effect of waste components on the hydraulic activity is an interesting object for the research. The possible increase of zinc incorporation present insecondary raw materials may lead to changes in behavior of pastes made from OPC. In this study zinc nitrate, chloride and oxide were added to Portland cement. The concentrations of 0.05, 0.1, 0.5 and 1.0 weight percent of zinc in cement were tested. After 1, 7, 28 and 90 days were measured the compressive and flexural strengths. The addition of salts of zinc modifies resulted compressive strength in various ways. The early compressive strength (1 day) decreases in comparison with the reference sample. This difference is probably due to a delay in tricalcium silicate hydration as shown by isothermal and isoperibolic calorimetry. As shown by scanning electron microscopy and X-ray diffraction, zinc is predominantly absorbed in CaZn2(OH)6.2

Druh

O - Ostatní výsledky

CEP obor

CA - Anorganická chemie

OECD FORD obor

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Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2014

Kód důvěrnosti údajů

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