Citation

Frangi A, Fontana M, Schleifer V. Fire Mater. 2005; 29(3): 127-146.

Copyright

(Copyright © 2005, John Wiley and Sons)

DOI

unavailable

PMID

unavailable

Abstract

Timber surfaces with perforations are unfavourable from a fire design point of view, since the perforations increase the surface area exposed to fire and facilitate an increased penetration of heat into the burning 49 zone. This can lead to an increased burning rate in comparison with heavy timber surfaces. In order to enlarge the theoretical and experimental background of the fire behaviour of timber surfaces with perforations, a series of fire tests was performed on timber assemblies made of hollow core elements with acoustic perforations and sound absorbers placed behind the perforated acoustic layer. This type of element is commonly used to improve ceiling sound absorption. The first part of the paper describes the results of the fire tests, in the second part a simplified calculation model for the burning rate is presented and compared with the test results. The model takes into account two different charring phases, before and after the perforated acoustic layer is completely charred. Good agreement between the test results and prediction of the calculation model is observed. Further the fire tests clearlv showed that the charring rate during the first phase is mainly influenced by the size and the position of the perforations as well as the thickness of the perforated acoustic layer. A correlation between the charring rate and these parameters is also presented and compared with the test results.