An X-ray CT scanning set-up and analysis pipeline for non-destructive assessment of fungal decay in wood has been successfully used to visualise and quantify fungal decay and relate it to wood structure at a submillimetre scale (De Ligne et al. 2022a). Initial hyphal penetration of solid wood specimens typically occurs via the major longitudinal pathways, being vessels for hardwoods and tracheids and resin canals for softwoods (Bravery 1975), with the fungus entering via the cross-sectional plane (end grain) (De Ligne et al. 2022a). In practice, wooden beams and engineered wood products are cut and designed so that the end grain exposed surface is small compared to the total exposed wood surface and the end grain is often protected in applications with a fungal decay risk. To assess degradation through the face grain, it is necessary to seal off the end grain of the wood specimens, especially when working with small-sized specimens. As such, fungal degradation is prevented from the end grain, allowing to assess the impact of material structure and barriers (for instance, a thermally modified outer layer) on fungal penetration and decay progress. However, in previous experiments on end grain sealed wood specimens, fungal decay did not occur for half of the plywood specimens (De Ligne et al. 2022b) and none of the CLT specimens (Jiang, 2025), while such materials can, of course, be decayed in practice through the face grain. The issue was hypothesized to be twofold: (1) a lower initial moisture content (f.i. 3% for the sealed CLT specimens) at the start of the experiment, as a two-week equilibration period at 65% RH was insufficient to restore a 12% moisture content of sealed specimens after oven-drying; and (2) an inadequate moisture supply for the fungus. An adapted method is proposed here and experimentally validated for solid beech specimens.
Keywords: fungal decay, X-ray CT, beech, engineered wood products, wood protection
Authors
Liselotte De Ligne
Laboratory of Wood Technology, Ghent University, Belgium
Joris Van Acker
Laboratory of Wood Technology, Ghent University, Belgium
Jan Van den Bulcke
Laboratory of Wood Technology, Ghent University, Belgium
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