Influence of Thermal Treatment on Properties of Ash Wood

The objective of this study was to investigate some of the properties of ash (Fraxinus excelsior L.) wood treated at a temperature of 185 °C for 3 h. We tested the samples’ physical properties, including their dimensional stability in the form of water absorption and radial/tangential swelling and their surface roughness, as well as their mechanical characteristics such as Brinel hardness and bending strength. Our results show that the water absorption and swelling values of the samples improved, ranging from 27% to 32% and from 21% to 46%, respectively. Also, the Brinell hardness of the thermally treated wood registered a slight decrease from 19.5 N/mm2 to 15.2 N/mm2 in the radial direction and from 15.7 N/mm2 to 12.2 N/mm2 in the tangential direction. It appears that the bending resistance of the samples decreased, which is generally thought to be an adverse effect of heat treatment on any wood species.