Factors Influencing the Charring Rate of Chinese Wood by using the Cone Calorimeter

Wood has better load-bearing capacity following the formation of a char layer when exposed to fire. The charring rate is the most important property of wood with respect to its fire resistance and fire integrity. The objectives of this study were to determine the effects of factors, including density, gas permeability, ring width, grain orientation, and heat flux, on the charring rate. The charring rates of six Chinese woods were tested with a cone calorimeter with densities of 0.35 to 0.69 g/cm3 and moisture contents of approximately 12%. The results indicated that density, gas permeability, and heat flux, but not the grain orientation, significantly affected the charring rate. There was a positive, linear correlation between the heat flux and the charring rate. The density was nearly linearly related to the charring rate for either softwood or hardwood; the correlation was not found for all woods. The positive, linear correlation between the gas permeability and the charring rate was only found along the grain.