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Experimentelle und numerische Untersuchung des hygrothermischen Verhaltens von Flachdachelementen mit Hohlkastensystem

Author(s):




Medium: journal article
Language(s): German
Published in: Bauphysik, , n. 1, v. 37
Page(s): 17-30
DOI: 10.1002/bapi.201510002
Abstract:

Experimental and numerical investigation on the hygrothermal behaviour of flat roof elements made in hollow boxed construction.

Due to their compactness non-ventilated flat roof constructions in wood require deeper knowledge about the construction-physical processes. The wooden roof sheathing below the vapour diffusion tight layer, in particular, runs an increased risk of hygric properties. Studies have shown that an excess of 20 % moisture content during a longer period of time implicates significant consequences, such as moulds, etc. The bonding can be significantly affected at such high moisture contents. For this reason, as part of a research project a measurement technology was installed during the new construction of a two family house and monitored over several years.
For comparative analysis areas with mineral fibrous and soft fibrous insulating material were established. Two experimental and one numerical methods were applied in order to assess the moisture content of the installed three-layer panel.
The first experimental method is based on the calculation of the moisture content from the measured relative humidity in the roof. For this, the sorption isotherm of three-layer panel used was determined. At the same time, the moisture content was recorded by resistance measurement in the areas with the mineral fibrous and soft fibrous insulating material. A transient hygrothermal calculation using the simulation program WUFI® was carried out for comparison of these experimental methods.
All three methods produce plausible results. Because of the maximum deviation of 2 % of one from another it can be assumed that the fluctuating behaviour of the equilibrium moisture content of the three-layer panel most likely moves in a range between about 11 to 19 % moisture. Thus it is situated below the critical limit of 20 % and does in theory not constitute a risk of hygric properties. Nevertheless the range of 20 % is quite high, for which reason the moisture resistance of the bond thereby should be noted.

Keywords:
moisture transfer wood moisture moisture transport hygrothermal simulation wood moisture content sorption isotherm non-ventilated flat roof soft fibrous insulating material component calculation sorption isotherm Wood fibre insulation
Available from: Refer to publisher
Structurae cannot make the full text of this publication available at this time. The full text can be accessed through the publisher via the DOI: 10.1002/bapi.201510002.
  • About this
    data sheet
  • Reference-ID
    10071410
  • Published on:
    19/02/2015
  • Last updated on:
    19/02/2015
 
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