Hydration Kinetics of Blended Cements for Application With Basalt Reinforcement

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F23%3A00371306" target="_blank" >RIV/68407700:21110/23:00371306 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1063/5.0146767" target="_blank" >http://dx.doi.org/10.1063/5.0146767</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0146767" target="_blank" >10.1063/5.0146767</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Hydration Kinetics of Blended Cements for Application With Basalt Reinforcement

Popis výsledku v původním jazyce

Silica fume (SF, amorphous polymorph of SiO2) is well known mineral admixture for concrete, especially for High Performance Concrete (HPC) structures like bridges, skyscrapers, tunnels etc. The benefits of SF, compared to other (easily available, lower cost) Supplementary Cementing Materials (SCM), is its high fineness and high content of reactive silica, i.e. high reactivity in hydration process. SF is thus not only substituting the Portland clinker, but also improving the durability measures of concrete, thanks to the better space filling by fine SF particles. Unfortunately, the high reactivity of SF results also to a drawback – intensive pozzolanic reaction of SF obviously means also intensive consumption of Ca(OH)2 and thus a risk of its depletion and of consequent decrease of pH to level where a steel reinforcing elements may corrode. In the contrary, the lower pH is beneficial for durability of basalt-based reinforcing elements. Nevertheless the knowledge of pH development in time is crucial. The present contribution deals with kinetics of individual processes controlling the pH of pore solution: Ca(OH)2 generation by Ordinary Portland cement (OPC) hydration; Ca(OH)2 consumption by carbonation; Ca(OH)2 consumption by pozzolanic reaction. The rate of individual processes was monitored by help of thermogravimetry and XRD. It was found that presence of Silica Fume is promoting the rate of Alite hydration since the SF is consuming the Ca(OH)2, and thus the Alite hydration equilibrium is shifted to the right.

Název v anglickém jazyce

Hydration Kinetics of Blended Cements for Application With Basalt Reinforcement

Popis výsledku anglicky

Silica fume (SF, amorphous polymorph of SiO2) is well known mineral admixture for concrete, especially for High Performance Concrete (HPC) structures like bridges, skyscrapers, tunnels etc. The benefits of SF, compared to other (easily available, lower cost) Supplementary Cementing Materials (SCM), is its high fineness and high content of reactive silica, i.e. high reactivity in hydration process. SF is thus not only substituting the Portland clinker, but also improving the durability measures of concrete, thanks to the better space filling by fine SF particles. Unfortunately, the high reactivity of SF results also to a drawback – intensive pozzolanic reaction of SF obviously means also intensive consumption of Ca(OH)2 and thus a risk of its depletion and of consequent decrease of pH to level where a steel reinforcing elements may corrode. In the contrary, the lower pH is beneficial for durability of basalt-based reinforcing elements. Nevertheless the knowledge of pH development in time is crucial. The present contribution deals with kinetics of individual processes controlling the pH of pore solution: Ca(OH)2 generation by Ordinary Portland cement (OPC) hydration; Ca(OH)2 consumption by carbonation; Ca(OH)2 consumption by pozzolanic reaction. The rate of individual processes was monitored by help of thermogravimetry and XRD. It was found that presence of Silica Fume is promoting the rate of Alite hydration since the SF is consuming the Ca(OH)2, and thus the Alite hydration equilibrium is shifted to the right.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20505 - Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; filled composites)

Projekt

<a href="/cs/project/GA21-00800S" target="_blank" >GA21-00800S: Chemické a fyzikální interakce výztuže na čedičové bázi s cementovou matricí</a><br>

Návaznosti

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

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název statě ve sborníku

Central European Symposium on Thermophysics 2022 (CEST 2022)

ISBN

—

ISSN

1551-7616

e-ISSN

1551-7616

Počet stran výsledku

6

Strana od-do

—

Název nakladatele

AIP Conference Proceedings

Místo vydání

New York

Místo konání akce

Olomouc

Datum konání akce

31. 8. 2022

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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