Abstract
The laboratory made full-scale OSB, which consisted of sugi (Cryptomeria japonica D. Don) strands for the face layers and recycled wood particles for the core layer, and four types of commercial wood-based panels were tested to evaluate their durability performance after having been subjected to an outdoor exposure for three years. The mechanical and dimensional properties of the panels were determined after three-year usage as the roof sheathing of a warehouse according to the JIS (Japanese Industrial Standard) and JAS (Japanese Agricultural Standard).
The results obtained were summarized as follows: The MOR and MOE retention after the outdoor exposure ranged from 30% to 70% corresponding to the resin type of the board used and the surface conditions. The IB strength for M-type particleboard decreased remarkably, and the thickness swellings of the commercial OSB and M-type particleboard were larger than those of the other panels. The laboratory-made OSB showed fairly good strength retentions; 68%, 55%, and 77% for MOR, MOE, and IB, respectively.
No strength reduction caused by the usage of the roof sheathing was found in the laboratory-made OSB. The strength reduction of the other panels could be estimated less than 10% of the initial strength. There was no significant difference between the wet-bending properties of the used panel and those of the controls.
