Laminating Effects in Glued-Laminated Timber Beams

Existing lamination and beam test results were analytically reviewed to quantify the laminating effect for European and North American glued-laminated (glulam) timber. The laminating effect is defined as the increase in strength of lumber laminations when bonded in a glulam beam compared with their strength when tested by standard test procedures. Fundamental concepts are presented to define the laminating effect, estimates are made of its magnitude, and relationships are presented to describe its character. Our review of experimental data indicated that the laminating effect ranged from 1.06 to 1.59 for European glulam and from 0.95 to 2.51 for North American glulam.