Measurement of dimensional stability of heat treated southern red oak (Quercus falcata Michx.)

The objective of this study was to investigate the effect of heat treatment on physical and mechanical properties including oven-dry density, weight loss, swelling, shrinkage, and hardness of southern red oak (Quercus falcata Michx.). The samples were treated at a temperature level of 190 °C for 3 h and 8 h. After heat treatment of the specimens, their dimensional stability in the form of swelling and shrinkage were determined by soaking them in water for 2 and 24 h. Hardness of samples as function of heat treatment was also measured using Janka hardness (ASTM D 1037-12). Tangential, radial and longitudinal swelling values of the samples exposed to 8 h heat treatment and soaked in water for 2 h were 0.245%, 0.236%, 0.098%, respectively. Corresponding values for the control samples were 0.504%, 0.455%, 0.135%. Overall hardness of the specimens was adversely influenced due to heat treatment. Based on the findings in this study shrinkage and swelling of the samples improved as a result of heat exposure. It appears that heat treatment would be a viable method to enhance dimensional stability of red oak for more effective utilization where enhanced hygroscopicity of such species is desired.