A testing method coupled with bending deformation and decay hazard was newly designed to evaluate mechanical performance of wood-based materials under fungal decay, and it was applied to plywood and particleboard as well as solid wood. The test specimens measuring 50×350mm×(thickness) were subjected to bending creep tests under progressive fungal attack with a brown-rot fungus [Tyromyces palustris (Berk. et Curt) Murr.] and a white-rot fungus [Coriolus versicolor (L. ex Fr.) Quél.] in the decay apparatus. After fixation of loading, the deflection at the center of the span length (300mm) was measured regularly as a criterion to determine its expected performance.
The difference in deflection between the inoculated specimen and the sterile sound control one was assumed to be due to strength reduction caused by the action of fungi, and the behavior of bending deformation varied depending on the durability of the specimens.
The method was shown to be particularly useful for the study of particleboard degradation in which high strength loss and large deflection in bending were occasionally observed at slight weight loss. It can be generally applied not only to untreated materials for estimation of their mechanical resistance to decay fungi, but also to treated ones for determination of their preservative efficacy.
