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| rdf:type
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| Description
| - Chemical admixttures are used to alter of the concrete properties for many years. The most important admixtures are accelerators and retarders, compounds that accelerate or retard setting or hardening, to decrease the water quantity needed to obtain a given degree of workability, or to entrain in order to increase the resistance of the concrete from freezing. The effect of retarding admixtures on the hydration of Portland cement has been extensively studied. Several theories have been proposed to explain how admixtures affect the hydration clinker compounds. These can be conveniently summarized as adsorption, precipitation, complexation a nucleation. This problem is very complex. Many organic compounds have the properties of retarder-saccharides, hydroxycarboxylic acids, lignosulfonates are examples. They effect in low concentrations. Most of them contain one or more groups in which oxygen atoms are attached to adjacent carbon atoms, such as HO-C-C=O, or otherwise able to approach each other closely. Adsorption on either a clinker phase or hydration product might cause retardation, in the latter case through interfering with growth. The effect of sucrose on the early hydration of Portland cement paste by determining of Ca2+ ions, calorimetry and differential thermal analysis (DTA) has been studied in this contribution. Compressive strengths of samples in the presence of different concentration of sucrose at 3, 7, 14, 28 and 90 days were determined. The concentration of free Ca2+ ions in hydrated cement paste during the first two hours of cement hydration for cement paste and heat of hydration by SETARAM calorimeter at 30°C in the presence and absence of sucrose as a retarder was measured. The resulting curves for both measurement methods show a signifiant difference, which is slowing down the cement hydration reaction by adding sucrose. DTA and compressive strengths curves also are changed considerably in presence sucrose.
- Chemical admixttures are used to alter of the concrete properties for many years. The most important admixtures are accelerators and retarders, compounds that accelerate or retard setting or hardening, to decrease the water quantity needed to obtain a given degree of workability, or to entrain in order to increase the resistance of the concrete from freezing. The effect of retarding admixtures on the hydration of Portland cement has been extensively studied. Several theories have been proposed to explain how admixtures affect the hydration clinker compounds. These can be conveniently summarized as adsorption, precipitation, complexation a nucleation. This problem is very complex. Many organic compounds have the properties of retarder-saccharides, hydroxycarboxylic acids, lignosulfonates are examples. They effect in low concentrations. Most of them contain one or more groups in which oxygen atoms are attached to adjacent carbon atoms, such as HO-C-C=O, or otherwise able to approach each other closely. Adsorption on either a clinker phase or hydration product might cause retardation, in the latter case through interfering with growth. The effect of sucrose on the early hydration of Portland cement paste by determining of Ca2+ ions, calorimetry and differential thermal analysis (DTA) has been studied in this contribution. Compressive strengths of samples in the presence of different concentration of sucrose at 3, 7, 14, 28 and 90 days were determined. The concentration of free Ca2+ ions in hydrated cement paste during the first two hours of cement hydration for cement paste and heat of hydration by SETARAM calorimeter at 30°C in the presence and absence of sucrose as a retarder was measured. The resulting curves for both measurement methods show a signifiant difference, which is slowing down the cement hydration reaction by adding sucrose. DTA and compressive strengths curves also are changed considerably in presence sucrose. (en)
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| Title
| - Effect of Sucrose as a Retarder on some Physico-Chemical Properties of Cement Paste
- Effect of Sucrose as a Retarder on some Physico-Chemical Properties of Cement Paste (en)
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| skos:prefLabel
| - Effect of Sucrose as a Retarder on some Physico-Chemical Properties of Cement Paste
- Effect of Sucrose as a Retarder on some Physico-Chemical Properties of Cement Paste (en)
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| skos:notation
| - RIV/68407700:21110/12:00197339!RIV13-MSM-21110___
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| http://linked.open...avai/predkladatel
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| http://linked.open...avai/riv/aktivita
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| http://linked.open...avai/riv/aktivity
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| http://linked.open...vai/riv/dodaniDat
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| http://linked.open...aciTvurceVysledku
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| http://linked.open.../riv/druhVysledku
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| http://linked.open...iv/duvernostUdaju
| |
| http://linked.open...titaPredkladatele
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| http://linked.open...dnocenehoVysledku
| |
| http://linked.open...ai/riv/idVysledku
| - RIV/68407700:21110/12:00197339
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| http://linked.open...riv/jazykVysledku
| |
| http://linked.open.../riv/klicovaSlova
| - Hydrating cement paste; retarders; sucrose; concentration of Ca2+ ions; DTA (en)
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| http://linked.open.../riv/klicoveSlovo
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| http://linked.open...ontrolniKodProRIV
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| http://linked.open...v/mistoKonaniAkce
| |
| http://linked.open...i/riv/mistoVydani
| |
| http://linked.open...i/riv/nazevZdroje
| - DEVELOPMENT OF MATERIALS SCIENCE IN RESEARCH AND EDUCATION
|
| http://linked.open...in/vavai/riv/obor
| |
| http://linked.open...ichTvurcuVysledku
| |
| http://linked.open...cetTvurcuVysledku
| |
| http://linked.open...UplatneniVysledku
| |
| http://linked.open...iv/tvurceVysledku
| - Hošková, Šárka
- Strnadová, Gabriela
- Rollová, Jitka
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| http://linked.open...vavai/riv/typAkce
| |
| http://linked.open.../riv/zahajeniAkce
| |
| number of pages
| |
| http://purl.org/ne...btex#hasPublisher
| - Czechoslovak Association for Crystal Growth
|
| https://schema.org/isbn
| |
| http://localhost/t...ganizacniJednotka
| |
| is http://linked.open...avai/riv/vysledek
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