The influence of moisture on the thermal conductivity of AAC

• Autorzy: Schoch T. , Kreft O.
• Konferencja: 5th International Conference on Autoclaved Aerated Concrete "Securing a sustainable future" to be held at Bydgoszcz to celebrate 60 years of AAC experience in Poland, Bydgoszcz, September 14-17, 2011
• Języki publikacji: EN

Abstrakty

EN

In recent years, questions emerged about how high level moisture contents might affect heat technical properties of building materials. Yet, existing standards and scientific publications, respectively, do not provide conclusive insights into the area of high rated moisture, since they are valid for the equilibrium moisture area only. Taking instructions of calculation according to harmonized European standards (EN ISO 10456, DIN EN 1745) as a basis, typical moisture contents of freshly produced AAC would theoretically involve immense surcharges on A, which would drastically affect thermal conductivities and, in turn, increase heating costs. Moreover, increasing risks of mould formation and other damages would be expected. Our experiments clearly demonstrate that actual increases in Gamma at production moisture levels are far below values stated in the European standards. In addition to this fundamental perception recent investigations have shown that the surcharge of moisture content under typical condition of AAC use in buildings the moisture conversion factor Fm is not higher than 5%. In several investigations a lower value for Fm have been found and can be used in the future for starting points of further investigations and tests.

Słowa kluczowe

EN

autoclaved aerated concrete; moisture concrete; thermal conductivity

PL

beton komórkowy; zawartość wilgoci; przewodność cieplna

• Wydawca: Fundacja Cement, Wapno, Beton
• Czasopismo: Cement Wapno Beton
• Rocznik: 2011
• Tom: nr spec.
• Strony: 44--48
• Opis fizyczny: Bibliogr. 8 poz., il.

Twórcy

autor

Schoch T.

autor

Kreft O.

• Xella Technology and Research, Germany

Bibliografia

• [1] EN 12 664. 2001. Thermal performance of building materials products - determination of thermal resistance by means of guarded hot plate and heat flow meter methods - dry and moist products of medium and low thermal resistance.
• [2] EN 1745. 2002. Masonry and masonry products - methods of determining design thermal values.
• [3] EN 1745. 2011. Masonry and masonry products - methods of determining thermal properties, draft document.
• [4] DIN V 4108-4. 2007. Thermal insulation and energy economy in buildings - hygrothermal design values.
• [5] Schoch T. 2005. The influence of material moisture on heat conductivity of AAC, proceedings of the International AAC conference in London.
• [6] FIW report 2005. Determination d'un coefficient de corrective relative a I'humidite pour le beton cellulaire Xella "St. Savin 500" ayant une masse volumique apparente entre 470 et 490 kg/m3.
• [7] Tenical report. 2010 . Determination of a correction coefficient for moisture content for celluar concrete Xella Ytong 450a and 350, Universitä Degli Studi di Padova.
• [8] Gutachten.2010. Gutachten über die Bestimmung des Feuchtezuschlages von Porenbetonplatten, Magistrat der Stadt Wien, Prüf-, Überwachungs- und Zertifizierungstelle der Stadt Wien.