Abstract
The reusability of decommissioned treated wood is primarily dependent on residual preservative retention and residual strength of the wood after service. Therefore, determining the residual preservative retention, bonding performance, and residual strength of spent treated wood can provide vital information to further recycling efforts. This report summarizes the latest research results on the recycling of decommissioned CCA treated wood at the Calhoun Research Station in Calhoun, LA. Nine decommissioned southern pine (Pinus, spp.) distribution poles and pole sections were evaluated for bending strength across and along the poles. Laminated crossarms made from spent utility pole wood and solid sawn crossarms made from virgin wood were compared for bending strength after retreated with penta. It was found that the strength of most decommissioned utility poles varied across, along each pole, and among the poles that were studied. The average modulus of rupture (MOR) and modulus of elasticity (MOE) of the utility pole wood in this study were 16.2% and 12.4%, respectively, lower than MOR and MOE values of longleaf pine virgin wood. However, the MOR and MOE of laminated crossarms made from decommissioned utility pole wood were comparable to the MOR and MOE of solid sawn crossarms made from virgin wood. This study was conducted using decommissioned distribution poles, which are small in the entire longleaf pine pole population. Further studies are warranted to examine the bending properties of decommissioned CCA treated transmission utility pole wood.
Keywords
Utility poles,
recycling,
chromated copper arsenate,
CCA,
growth rings,
CCA retention,
bending strength,
small clear samples,
crossarms,
Calhoun Research Station,
CRS
Citation
Piao, Cheng; Shupe, Todd F.; Groom, Leslie; Nipper, W. Allen. 2009. Research update for the treated wood reusing program at the Calhoun Research Station. In: 105th Annual Meeting of the American Wood Protection Association. San Antonio, TX: American Wood Protection Association. 209-215.