TU Darmstadt / ULB / TUbiblio

Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume

Berger, Felix ; Ukrainczyk, Neven ; Bogner, Andreas ; Hirsch, Astrid ; Dehn, Frank ; Koenders, Eduardus (2023)
Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume.
In: ce/papers : Proceedings in Civil Engineering, 6 (6)
doi: 10.1002/cepa.2995
Artikel, Bibliographie

Dies ist die neueste Version dieses Eintrags.

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: 2023
Autor(en): Berger, Felix ; Ukrainczyk, Neven ; Bogner, Andreas ; Hirsch, Astrid ; Dehn, Frank ; Koenders, Eduardus
Art des Eintrags: Bibliographie
Titel: Thermodynamic Modeling of Sulfuric and Acetic Acid Attack on Hardened Cement Paste: Effect of Silica Fume
Sprache: Englisch
Publikationsjahr: Dezember 2023
Ort: 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: 10.1002/cepa.2995
Zugehörige Links:
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
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: 29 Mai 2024 07:19
Letzte Änderung: 29 Mai 2024 07:19
PPN:
Export:
Suche nach Titel in: TUfind oder in Google

Verfügbare Versionen dieses Eintrags

Frage zum Eintrag Frage zum Eintrag

Optionen (nur für Redakteure)
Redaktionelle Details anzeigen Redaktionelle Details anzeigen