Influence of density and moisture content on heat release properties of wood
2008
Kikuchi, S.(Hokkaido. Forest Products Research Inst., Asahikawa (Japan)) | Kawarasaki, M.
The Building Standard Law of Japan was revised in 1998 and the test method for evaluating fire prevention materials was changed from the conventional surface flammability test to the heat release test. This is because the heat release property is the key factor in characterizing the flammability of building materials. To develop fire prevention materials corresponding to various wood materials, it is necessary to clarify the heat release properties of wood. To accomplish this, heat release tests were carried out on six species using the ISO cone calorimeter. The species tested were Pinus densiflora, Larix leptolepis, Chamaecyparis obtusa, Cryptomeria japonica, Abies sachalinensis and Fraxinus mandshurica. The specimens were heated at an irradiance level of 50 kW/square m, heat release rate, total heat release and effective heat of combustion were measured. Wood had a higher first peak heat release rate just after ignition and high second peak, when the back of the specimen began to burn. After flaming combustion ceased, glowing combustion of the carbonized layer continued for a long time. Heat release rate in the flaming period was related to the original moisture content of the wood. There were clear differences in the total heat release of specimens between the conifers and F. mandshurica, and these increased linearly with density. The effective heat of combustion on a dry basis was 14-16 MJ/kg in the flaming period, and 29-32 MJ/kg in the glowing one.
显示更多 [+] 显示较少 [-]