John J. Janowiak

Finite-Element Modeling of Red Maple Glued-Laminated T-Beams and Bridge Behavior

Finite-element modeling methods are presented using an existing finiteelement program to (1) predict the stiffness increase, due to the addition of deck panels, for red maple glued-laminated (glulam) T-beam assemblies relative to beams with no deck panels; and (2) predict the midspan beam deflection for a red maple glulam longitudinal stringer–transverse deck bridge for two loading conditions (one lane loaded and two lanes loaded). The red maple T-beam stiffness increase was determined for T-beams assembled with and without gaps between deck panels. The T-beam stiffness increase was predicted to within 5 percent for T-beams assembled with gaps between deck panels and to within 3 percent for T-beams assembled with no gaps between deck panels. Red maple glulam longitudinal stringer–transverse deck bridge maximum midspan beam deflections were predicted to within 6 percent for one-lane loading and to within 7 percent for two-lane loading.

Mechanical Performance of Nail-Laminated Posts Manufactured from Reclaimed Chromated Copper Arsenate–Treated Decking Lumber

Abstract This study determined the mechanical properties of nail-laminated (nail-lam) posts manufactured from reclaimed chromated copper arsenate (CCA)–treated decking lumber. Though CCA-treated lumber is no longer accepted for use in residential applications, it is permitted in agricultural and industrial applications where health and environmental impacts are deemed to be minimal. This project focused on the reuse potential of this lumber for fabricating structural nail-lam members commonly used in agricultural post frame utility buildings. Significant amounts of waste CCA-treated lumber are generated by people replacing decks. Currently, this lumber is mostly landfilled as disposal waste. Finding other uses for this discarded material could reduce the waste burden of decking removed from service each year. For this study, 15-year-old decking material slated for removal and composed of nominal 2 by 6 CCA-treated Southern yellow pine (SYP; Pinus spp.) lumber was carefully reclaimed for structural post me...