InTrans / Aug 14, 2018

Yellow Poplar glulam timber beam performance

Yellow Poplar is currently not used in structural gluedlaminated
(glulam) timber construction, but its properties suggest that it may be feasible for this purpose. Using Yellow Poplar, we designed glulam beam combinations to target bending stresses of 2,400 lb/in2 and modulus of elasticity of 1.8 ÌÑ 106 lb/in2. The glulam combinations were designed with E-rated lumber grades in 25 percent of the outer laminations (top and
bottom) and No. 2 grade lumber in 50 percent of the center laminations. In addition to evaluating 45 fullsized beams, more than 200 end-jointed lumber specimens were tested in tension to compare individual specimen performance to full-size beam performance. Results for the Yellow Poplar glulam beams met the target design levels, indicating that this species is a feasible candidate for structural glulam construction.