Journal Published Online: 01 July 1973
Volume 1, Issue 4

Effect of Pyrolytic Temperatures on the Longitudinal Strength of Dry Douglas-Fir



Compressive and tensile strength of dry Douglas-fir was measured through rapid constant deformation rate tests at temperatures from 25 to 288°C, at initial thermoequilibrium and after 2 h of heating.

The tensile strength decreased slowly with increasing temperatures to 175°C. Above 175°C, the tensile strength reduces rapidly. This is attributed to alteration of the cellulosic fraction of wood.

The compressive strength decreases more uniformly with temperatures increasing to 288°C due to changes occurring in all three basic wood components with change in temperature.

A first-order reaction equation for bond rupture/formation was adopted to describe the response. Including only terms for bond rupture resulted in good correlation to the observed strength response at reaching thermoequilibrium.

Author Information

Schaffer, EL
Forest Products Laboratory, USDA
Pages: 11
Price: $25.00
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Stock #: JTE10025J
ISSN: 0090-3973
DOI: 10.1520/JTE10025J