A Probabilistic Approach to Wood Charring Rate

VTT WORKING PAPERS 31

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Gamma
Lognormal

probability density

charring depth l (mm)

ESPOO 2005

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time (min)

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charring rate (m m /m in)

A Probabilistic Approach to
Wood Charring Rate
Jukka Hietaniemi
VTT Building and Transport

ISBN 951–38–6583–5 (URL: http://www.vtt.fi/inf/pdf/)
ISSN 1459–7683 (URL: http://www.vtt.fi/inf/pdf/)
Copyright © VTT 2005
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Technical editing Maini Manninen

Published by

Series title, number and report code of publication

VTT Working Papers 31
VTT–WORK–31
Author(s)

Hietaniemi, Jukka
Title

A Probabilistic Approach to Wood Charring Rate
Abstract

This report presents a probabilistic model for wood charring rate and an application of the model to assess fire resistance of a wooden load-bearing beam. The model is an empical one, based on quantification of the dependence of the wood charring rate on the principal physical factors governing the charring process. These factors include the influence of the heat flux exposing the wood surface, the wood density and moisture content as well as the ambient oxygen concentration. The application introduces a novel approach to assess the endurance

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