Relationship between incipient decay, strength, and chemical composition of Douglas-fir heartwood
Winandy, J. and Morrell., J.
1993
Decay, mechanical properties, wood chemistry, brown rot, Decay, mechanical properties, wood chemistry, brown rot
Winandy, J. and Morrell., J., (1993), "Relationship between incipient decay, strength, and chemical composition of Douglas-fir heartwood", .
Abstract: |
A new laboratory technique to simulate the initiation of wood decay and to assess the effects of incipient decay on material properties is described. Douglas-fir heartwood specimens were exposed to brown-rot (Postia placenta and Gloeophyllum trabeum) fungi for various periods. Bending properties were determined by nondestructive and destructive tests. and chemical composition of specimens was analyzed. Weight losses of 1 to 18% were linearly related to strength losses of 5 to 70%. Wood strength loss by brown-rot fungi was also closely related to degradation of hemicellulose components. Hemicellulose sidechains, such as arabinose and galactose, were degraded in the earliest stages of decay; main-chain hemicellulose carbohydrates. such as mannose and xylose, were degraded in the later stages. Changes in glucose content. a measure of residual cellulose. were minimal. Our technique was effective for establishing and assessing brown-rot decay. |
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