The properties of heat treated fir wood on biological, mechanical, physical and outdoor durability

In this thesis, two different thermal treatment methods at three different temperature and time were applied on Turkish fir (Abies nordmanniana subsp. bornmulleriana Mattf.) wood. Thermal treatment has caused some physical and mechanical changes on Turkish fir wood such as weight, density, water adsorption, and dimensional changes, static bending strength, modulus of elasticity in static bending and compression parallel to grain were examined. Also, the heat treated samples Turkish fir and impregnated Scotch pine (Pinus sylvestris L.) samples had been subjected to natural aging tests for a period of 5 months. The color change and surface roughness of wood samples were analyzed during certain periods of natural aging time. Nitrogen gas and linseed oil were used for the purpose of heat transfer medium. Heat factors 150, 180 and 200 0C and time factors 2,4 and 6 hours were used for each thermal treatment methods. Impregnated chemicals selected CCA and CCB because of their strong wood protect characteristics. Two different heat treatment methods under nitrogen gas and linseed oil are compared statistically. The heat treated Turkish fir wood can be used at the application of the outdoor conditions. As a result, the best performance of the heat treatment methods based on the results of the application temperature and time, the related statistical analysis show: a) 6 hours application at 200 0C in nitrogen atmosphere b) 2 hours at 150 0C in oil heat treatment for water adsorption, swelling, color stability and surface roughness of wood having favorable properties. Especially, oil heat-treated wood's physical, mechanical, color stability and surface roughness properties are found to be better than untreated wood.