Residual Strength and Stiffness of Lumber from Decommissioned Chromated Copper Arsenate–Treated Southern Pine Utility Poles

Abstract

The reusability of decommissioned treated wood is primarily dependent on the residual strength of the wood after service. Determining the residual strength can provide useful information for structural design and reuse of the decommissioned treated wood. This study evaluated the residual strength of decommissioned chromated copper arsenate–treated utility pole wood. Eleven decommissioned southern pine (Pinus spp.) distribution poles and pole sections were evaluated, using small clear samples, for bending strength and stiffness across and along each pole. Results showed that the strength of the decommissioned treated wood varied across and along each pole and among the poles. Average modulus of rupture (MOR) was 80.9 percent of the typical MOR of longleaf pine (Pinus palustris) virgin wood, and average modulus of elasticity (MOE) was 83.9 percent of the typical MOE. Average MOR of the samples in the outer surface (first test zone) was 7.5 percent lower than the average MOR of the adjacent samples toward th...