This paper presents test evaluation results for red maple structural g
lued-laminated (glulam) beams manufactured from two different lumber r
esources. Two types of red maple glulam beam combinations were evaluat
ed: 1) a glulam combination designed with E-rated lumber in 25 percent
of the outer laminations (top and bottom) and visually graded lumber
in 50 percent of the center laminations; and 2) a wide-width glulam co
mbination with laminations made from nominal 2- by 4- and 2- by 6-inch
No. 2 grade lumber laid edge-to-edge having staggered end joints (ter
med 2 by 4/2 by 6 glulam combination). The two research studies differ
ed in that one study obtained red maple lumber using common sawing pra
ctices used for appearance hardwood lumber recovery, whereas the other
study exclusively obtained lumber from the red maple log cants that h
ad been processed for removal of furniture-grade material. Given these
two lumber resources, the test results from the two studies showed th
at it was feasible to develop structural glulam combinations made from
E-rated lumber that would meet or exceed a target design bending stre
ss of 2,400 psi and a target modulus of elasticity (MOE) of 1.8 x 10(6
) psi. In addition, the 2 by 4/2 by 6 glulam combination exceeded publ
ished design stresses for vertically laminated bending strength, MOE i
n both the horizontally and vertically laminated orientations, and hor
izontal shear stress in the vertically laminated orientation; Based on
the results of the 2 by 4/2 by 6 glulam combination, it was determine
d that edge gluing the laminations to form wide-width lumber is not re
quired to achieve targeted strength and stiffness levels. Data analysi
s showed that ASTM D 3737 procedures developed for softwood species ac
curately predict beam stiffness and provide conservative bending and h
orizontal shear strength estimates for red maple glulam beams. Also, i
t was shown that results from ASTM D 143 shear-block tests could be us
ed to accurately predict horizontal sheer strength of 2 by 4/2 by 6 re
d maple glulam beams.