Durability of Thermally Modified Wood of Gmelina arborea and Tectona grandis Tested under Field and Accelerated Conditions

This study evaluated the durability in terms of decay and mechanical resistance of thermally modified (TM) wood of Tectona grandis and Gmelina arborea treated at 160, 180, 200 and 220 degrees C. The TM wood of both species treated above 200 degrees C and 180 degrees C respectively presents lower weight loss (WL) after 300 days exposure in field and accelerated testing. It was also found that in field testing over 180 degrees C, the module of elasticity (MOE) and module of rupture (MOR) of the exposed and unexposed stakes of TM wood were not affected. Accelerated tests showed that the loss in flexural resistance was reflected more in the MOR than in the MOE. Finally, the accelerated and field tests showed that G. arborea and T. grandis TM wood treated at 180, 200 and 220 degrees C present statistically similar values of WL and flexural mechanical resistance.