The regression analysis of the charring rate for different species of wood was made, equations (3)-(6) were obtained, the predicted values of the charring rate calculated using the equations (3)-(6) are presented in Fig.
9597, which was obtained in predicting the charring rate of aspen, fir R = 0.
After the sample cooled down, the charring depth H, mm of wood under research was measured using sliding callipers.
The results of charring research, which was carried out with different species of wood using one-side heating chamber, are shown in Figs 10 and 11.
Charring of wood is closely related to the combustion characteristics of wood components--hemicellulose, cellulose and lignin--which influence formation of char.
Charring of wood is also dependent on the heat load applied on the structural surface and change in the value of heat load depending on the length of thermal exposure (Taubkin 1999).
4 consist of rules for calculating notional charring rate dependent on density:
where C--notional charring rate (mm/min); D--wood density with moisture content 12% (kg/[m.
The aim of this article is to study the effect of variability of charring along the members of wooden floor and wall assemblies insulated with heat-resistant mineral wools, such as stone wool and heat-resistant glass wool, and to detect the possible influence of density of wood on the charring rate.
Charring is the most important parameter in the design of timber-frame members for fire resistance.
Charring takes place mainly on the fire-exposed narrow side.