Abstract:

Conditioning of 25 mm thickness dried Eucalyptus camaldulensis lumber (EL) was carried out in small capacity laboratory batch kiln, and rheology behavior including elastic strain and mechano-sorptive strain was analyzed by slicing method. Main results are as follows: mean moisture content(MC) of lumber rises 2.5%～3.0%, while MC of surface rises 5% because surface is the main moisture gained zone. Compressive EL strain decreases significantly until duration of conditioning is up to 3 h, while the tensile EL strain doesn't have significant change during the whole conditioning. The compressive EL strain of sub-surface is larger than that of surface during middle and later of conditioning, so reverse stress gradient is formed. The surface casehardening zone is softened by moisture gained and complementary shrinkage makes elastic strain and MS strain decrease, but due to the effect of drying history, the change of MS strain lags to that of MC.

Key words: Eucalyptus camaldulensis, final conditioning, moisture content (MC), rheology behavior