Berger, Felix ; Ukrainczyk, Neven ; Bogner, Andreas ; Hirsch, Astrid ; Dehn, Frank ; Koenders, Eduardus (2024)
Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume.
In: ce/papers : Proceedings in Civil Engineering, 2023, 6 (6)
doi: 10.26083/tuprints-00027237
Artikel, Zweitveröffentlichung, Verlagsversion
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Kurzbeschreibung (Abstract)
The exposure of concrete structures to acid attack is a growing concern. This study employs thermodynamic modeling to investigate the changes in phase assemblage of powdered cement pastes subjected to a wide range of sulfuric and acetic acid concentrations. A modeling approach utilizing IPHREEQC implemented through Matlab is presented, and the obtained results are compared with pH measurements and compositions of equilibrated calcium and sulfate solutions. The influence of incorporating 11% silica fume (SF) as a replacement for cement predicted a 70% reduction of Portlandite content in the hardened cement paste. Consequently, the acid attack processes and subsequent pH reduction are affected. The modeling approach demonstrates good agreement with experimental data for acetic acid, across a broad range of acid concentrations, for both Portland cement and a blend with SF, without the need for any fitting parameters. However, significant discrepancies between the model and experiments are observed in the case of sulfuric acid. This discrepancy arises due to the formation of lump pieces of material in the experimental setup at higher acid concentrations. These lumps consist of a thin layer of altered hardened cement paste, primarily composed of sulfate‐rich phases, encapsulating unaltered hardened cement paste. Since the reaction was not homogeneous and the powder did not entirely react, the sulfuric attack experimental setup was not representative for validating the thermodynamic model.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2024 |
| Autor(en): | Berger, Felix ; Ukrainczyk, Neven ; Bogner, Andreas ; Hirsch, Astrid ; Dehn, Frank ; Koenders, Eduardus |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume |
| Sprache: | Englisch |
| Publikationsjahr: | 27 Mai 2024 |
| Ort: | Darmstadt |
| Publikationsdatum der Erstveröffentlichung: | Dezember 2023 |
| Ort der Erstveröffentlichung: | Berlin |
| Verlag: | Ernst & Sohn, a Wiley brand |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | ce/papers : Proceedings in Civil Engineering |
| Jahrgang/Volume einer Zeitschrift: | 6 |
| (Heft-)Nummer: | 6 |
| DOI: | 10.26083/tuprints-00027237 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/27237 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichung DeepGreen |
| Kurzbeschreibung (Abstract): | The exposure of concrete structures to acid attack is a growing concern. This study employs thermodynamic modeling to investigate the changes in phase assemblage of powdered cement pastes subjected to a wide range of sulfuric and acetic acid concentrations. A modeling approach utilizing IPHREEQC implemented through Matlab is presented, and the obtained results are compared with pH measurements and compositions of equilibrated calcium and sulfate solutions. The influence of incorporating 11% silica fume (SF) as a replacement for cement predicted a 70% reduction of Portlandite content in the hardened cement paste. Consequently, the acid attack processes and subsequent pH reduction are affected. The modeling approach demonstrates good agreement with experimental data for acetic acid, across a broad range of acid concentrations, for both Portland cement and a blend with SF, without the need for any fitting parameters. However, significant discrepancies between the model and experiments are observed in the case of sulfuric acid. This discrepancy arises due to the formation of lump pieces of material in the experimental setup at higher acid concentrations. These lumps consist of a thin layer of altered hardened cement paste, primarily composed of sulfate‐rich phases, encapsulating unaltered hardened cement paste. Since the reaction was not homogeneous and the powder did not entirely react, the sulfuric attack experimental setup was not representative for validating the thermodynamic model. |
| Freie Schlagworte: | cementitious materials, sulfuric acid attack, silica fume, pozzolanic reaction, thermodynamic modeling, IPHREEQC, solid‐liquid phase equilibration experiments |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-272371 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 600 Technik, Medizin, angewandte Wissenschaften > 624 Ingenieurbau und Umwelttechnik |
| Fachbereich(e)/-gebiet(e): | 13 Fachbereich Bau- und Umweltingenieurwissenschaften 13 Fachbereich Bau- und Umweltingenieurwissenschaften > Institut für Werkstoffe im Bauwesen |
| Hinterlegungsdatum: | 27 Mai 2024 12:54 |
| Letzte Änderung: | 28 Mai 2024 09:46 |
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| Suche nach Titel in: | TUfind oder in Google |
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- Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume. (deposited 27 Mai 2024 12:54) [Gegenwärtig angezeigt]
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