An analysis of the physical properties of recovered CCA-treated wood from residential decks

摘要

A large volume of CCA-treated wood removed from residential decks is disposed of in landfills every year, and better environmentally conscious alternatives are needed. Recycling CCA-treated wood from the decks could be a feasible alternative, but there is a lack of knowledge regarding the physical properties of the material. This research analyzed the chemical and mechanical properties of spent CCA-treated wood from residential decks to evaluate the material for reuse in other applications. Several of the joists and the decking of removed decks were found to be below the originally stated retention level. The joists had higher retention levels, and length of service was not a factor in level of chemical retention in the decking or joists. The spent decking had similar stiffness properties, but the bending strength was lower than recently treated material. As with the chemical properties, the mechanical properties were not affected by the amount of time the deck was in service. Overall, it was found that the preservative retention properties were lower than expected, the stiffness was equal to, and the strength was lower than, recently CCA-treated wood. This does not indicate that the material is unusable, but aids in determining suitable applications where recycled CCA-treated wood can be used.