The purpose of this small study was to examine the effect of various test methods upon the bending moduli of elasticity and to determine the bending strength of selected Douglas-fir and spruce laminated veneer lumber specimens.
Unseasoned spruce heart veneer was incised and steam-press dried using platen pressures of 25, 100 and 200 psi. Three-ply plywood panels were then prepared from these densified veneers. Results showed that the stiffness values for laminated veneer lumber (LVL) made with low stiffness SPF veneer or combinations of SPF and Douglas-fir veneer can be greatly increased and meet the 2,000,000 psi MOE marketing requirement using two methods. One involves impregnating unseasoned SPF veneer with phenolic resin and the second method involves using a special lay-up of the SPF and Douglas-fir veneers. These results will greatly help in marketing LVL using western veneer species. New technology of incising, moisture tolerant adhesives and self-generated steam developed at Forintek substantially reduced pressing time by about 40% which will make the manufacture of LVL more economical.
The purpose of this study was to determine flatwise and edgewise bending strength ("MOR") and stiffness ("MOE") of spruce and pine 1.5-inch by 3.5-inch by 48-inch laminated veneer lumber ("LVL") specimens parallel to grain. The experimental spruce and pine data was pooled together to give a combined spruce-pine data set.
Appendix 1 to Forestry Canada No. 35, Contract no. 1812L007 on
lumber and laminated veneer strength.
This progress report contains work performed for the project "Non-residential Applications of Glulam". It includes the experimental and analytical results obtained on laminating lumber grades, finger joints, tension and compression glulam grades, truss plate/glulam joints, and metal- plated glulam trusses.