Deterioration Mechanisms: Difference between revisions

From Saltwiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 69: Line 69:
Viele poröse Baustoffe erfahren in Abhängigkeit vom Feuchtegehalt ein Dehnen und Schwinden, die wenn sie in steigem Wechsel auftreten, zu starken Schäden führen können. In welchem Ausmaß diese Prozesse erfolgen, hängt von der Zusammensetzung, der Porenstruktur und dem Feuchteangebot ab. Sind diese Stoffe zusätzlich mit hygroskopischen Salzen belastet, so stellt sich eine neue, im Vergleich zum salzfreien Stoff, höhere Gleichgewichtsfeuchte ein, die von der Salzart und -konzentration abhängt (siehe auch <bib id="Vogt.etal:1993" />).
Viele poröse Baustoffe erfahren in Abhängigkeit vom Feuchtegehalt ein Dehnen und Schwinden, die wenn sie in steigem Wechsel auftreten, zu starken Schäden führen können. In welchem Ausmaß diese Prozesse erfolgen, hängt von der Zusammensetzung, der Porenstruktur und dem Feuchteangebot ab. Sind diese Stoffe zusätzlich mit hygroskopischen Salzen belastet, so stellt sich eine neue, im Vergleich zum salzfreien Stoff, höhere Gleichgewichtsfeuchte ein, die von der Salzart und -konzentration abhängt (siehe auch <bib id="Vogt.etal:1993" />).
<br clear=all>   
<br clear=all>   
-->
-->=== [[Thermic Effects]]  ===
=== [[Thermic Effects]]  ===
Since wet materials are much better heat conductor than dry materials, a higher moisture content lead to a change of temperature differences in a building material and thus to a change in the thermal stretching and shrinkage. Since a temperature compensation is faster, the thermal stresses will decrease normally.
Since wet materials are much better heat conductor than dry materials, a higher moisture content lead to a change of temperature differences in a building material and thus to a change in the thermal stretching and shrinkage. Since a temperature compensation is faster, the thermal stresses will decrease normally.


Line 76: Line 75:


In recent years, the previous models of the mechanisms of damage by salts were checked and had to be modified to some extent.
In recent years, the previous models of the mechanisms of damage by salts were checked and had to be modified to some extent.
 
-->
== Literature  ==
== Literature  ==



Revision as of 21:06, 30 July 2012

Authors: Michael Steiger, Hans-Jürgen Schwarz

back to SaltWiki:Community_portal

Abstract

Models that can lead to salt-induced damage are presented.


This article will be released soon.

Thermic Effects

Since wet materials are much better heat conductor than dry materials, a higher moisture content lead to a change of temperature differences in a building material and thus to a change in the thermal stretching and shrinkage. Since a temperature compensation is faster, the thermal stresses will decrease normally.

New findings according to decay mechanisms

In recent years, the previous models of the mechanisms of damage by salts were checked and had to be modified to some extent. -->

Literature

[Becker.etal:1916]Becker, G.F.; Day, A.L. (1916): Notes on the Linear Force of Growing Crystals. In: Journal of Geology, 24 (4), 313-333, UrlLink to Google Scholar
[Bruhns.etal:1913]Bruhns, W.; Mecklenburg, W. (1913): Über die sogenannte "Kristallisationskraft". In: Sechster Jahresbericht des Niedersächsischen Geologischen Vereins zu Hannover, (), 92-115Link to Google Scholar
[Buil:1983]Buil, Michel (1983): Thermodynamics and Experimental Study of the Crystallization Pressure of Water Soluble Salts. In: F.H. Wittmann (eds.): Materials Science and Restoration, Lack und Chemie, Filderstadt, 373-377.Link to Google Scholar
[Correns.etal:1939]Correns, Carl W.; Steinborn, W. (1939): Experimente zur Messung und Erklärung der sogenannten Kristallisationskraft. In: Zeitschrift für Kristallografie, (101), 117-133Link to Google Scholar
[Correns:1926]Correns, Carl W. (1926): Über die Erklärung der sogenannten Kristallisationskraft. In:: Preuss. Akad. der Wissensch, Sitzungsband, de Gruyter, 81-88.Link to Google Scholar
[Coussy:2006]The entry doesn't exist yet.
[Desarnaud.etal:2016]The entry doesn't exist yet.
[Duttlinger.etal:1993]Duttlinger, Werner; Knöfel, Dietbert (1993): Salzkristallisation und Salzschadensmechanismen. In: Snethlage, Rolf (eds.): Jahresberichte Steinzerfall - Steinkonservierung 1991, Ernst & Sohn, (Berlin), 197-213.Link to Google Scholar
[Espinosa-Marzal.etal:2010]Espinosa-Marzal, Rosa M.; Scherer, George W. (2010): Advances in Understanding Damage by Salt Crystallization. In: Accounts of Chemical Research, 43 (6), 897-905, UrlLink to Google Scholar
[Everett:1961]Everett, D.H. (1961): The thermodynamics of frost damage to porous solids. In: Transactions of the Faraday Society, 57 (), 1541-1551Link to Google Scholar
[Flatt.etal:2007]Flatt, Robert J.; Steiger, Michael; Scherer, George W. (2007): A commented translation of the paper by C.W. Correns and W. Steinborn on crystallization pressure. In: Environmental Geology, 52 (2), 187-203, 10.1007/s00254-006-0509-5Link to Google Scholar
[Flatt:2002]Flatt, Robert J. (2002): Salt damage in porous materials: how high supersaturations are generated. In: Journal of Crystal Growth, 242 (3), 435-454Link to Google Scholar
[Goranson:1940]The entry doesn't exist yet.
[Hall.etal:1984]The entry doesn't exist yet.
[Mortensen:1933]Mortensen, Hans (1933): Die 'Salzprengung' und ihre Bedeutung für die regionalklimatische Gliederung der Wüsten. In::, Justus Perthes, 130-135.Link to Google Scholar
[Scherer:1999]Scherer, George W. (1999): Crystallization in pores. In: Cement and Concrete Research, 29 (), 1347-1358Link to Google Scholar
[Scherer:2004]Scherer, George W. (2004): Stress from crystallization of salt. In: Cement and Concrete Research, 34 (4), 1613–1624, UrlLink to Google Scholar
[Steiger.etal:2008]Steiger, Michael; Asmussen, Sönke (2008): Crystallization of sodium sulfate phases in porous materials: The phase diagram Na2SO4–H2O and the generation of stress. In: Geochimica et Cosmochimica Acta, 72 (17), 4291-4306, UrlLink to Google Scholar
[Steiger.etal:2014]Steiger, Michael; Charola A. Elena; Sterflinger, Katja (2014): Weathering and Deterioration. In: Siegesmund S.; Snethlage R. (eds.): Stone in Architecture, Springer Verlag Berlin Heidelberg, 223-316, 10.1007/978-3-642-45155-3_4.Link to Google Scholar
[Steiger:2003b]Steiger, Michael (2003): Salts and Crusts. In: Brimblecomb, Peter (eds.): Air Pollution Reviews – Vol. 2: The effect of air pollution on the Built Environment, Imperial College Press, 133-181.Link to Google Scholar
[Steiger:2005]Steiger, Michael (2005): Crystal growth in porous materials: I. The crystallization pressure of large crystals. In: journal of Crystal Growth, 282 (3), 455-469, Url, 10.1016/j.jcrysgro.2005.05.007Link to Google Scholar
[Steiger:2005b]Steiger, Michael (2005): Crystal growth in porous materials: II. The influence of crystal size. In: Journal of Crystal Growth, 282 (3), 470-481, 10.1016/j.jcrysgro.2005.05.008Link to Google Scholar
[Steiger:2006]Steiger, Michael (2006): Crystal growth in porous materials: Influence of supersaturation and crystal size. In: Fort, Rafael; Alvarez de Buergo, Monica; Gomez-Heras, Miquel; Vazquez-Calvo, Carmen (eds.): Heritage, Weathering and Conservation: Proceedings of the International Heritage, Weathering and Conservation Conference (HWC-2006), 21-24 June 2006, Madrid, Spain, Taylor & Francis, 245-251.Link to Google Scholar
[Steiger:2009]Steiger, Michael (2009): Mechanismus der Schädigung durch Salzkristallisation. In: Schwarz, Hans-Jürgen; Steiger, Michael (eds.): Salzschäden an Kulturgütern: Stand des Wissens und Forschungsdefizite, Eigenverlag, 66-80.Link to Google ScholarFulltext link
[Taber:1916]Taber, Stephen (1916): The Growth of Crystals under External Pressure. In: American Journal of Science, (41), 532-556Link to Google Scholar
[Weyl:1959]Weyl, Peter K. (1959): Pressure Solution and the Force of Crystallisation - A Phenomenological Theory. In: Journal of Geophysical Research, 64 (11), 2001-2025Link to Google Scholar