Influence of Thermal Treatment on the Mechanical Properties of Pinewood

Abstract

The influence of thermal treatment on the compression strength and static bending resistance of pinewood has been investigated. The thermal treatment conditions close to real technological regimes were selected. The samples were dried at 60, 80, 100 and 120 °C for 24, 48, 72 and 96 hours. Linear dimensions of the samples were 20 mm × 20 mm in cross section and length 30 mm for compression and 300 mm for bending test. It was shown that the thermal treatment increases compression resistance parallel to the grain, while compression perpendicular to the grain and bending strength decreases. The increase of thermal treatment regimes decreases bending strength of pinewood. Average width of annual rings also influences mechanical properties; larger width of annual rings increases compression strength perpendicular to the grain in radial direction. Static bending at these conditions reaches the lowest values. The character of dependencies between static bending strength and width of annual rings does not change under thermal treatment.