This study evaluated the effect of two different incisors followed by chromated copper arsenate pressure treatment on the bending strength and stiffness of No. 2 and better nominal 2 x 4 inch (38 x 89 mm) spruce-pine-fir and hem-fir lumber. The double-density incising method, developed at Forintek, allows SPF to meet the CSA O80 wood preservation standards. The high-speed incisor was developed by Forintek for operation immediately behind the planer in a sawmill to produce a treatable lumber product. The prototype tested here employed two solid rollers to lay down two superimposed patterns of incisions at a density of 17500/m2. Approximately 2900 specimens of SPF and 1200 specimens of hem-fir were sorted into nine and four matched groups, respectively, according to their average flatwise modulus of elasticity values tested in centre point bending. The matched groups were then given various combinations of drying, incising and pressure treatments. Bending strength properties were tested. It was found that kiln-dried SPF and green hem-fir commercial dimension lumber, treated by the above processes, can be safely used for all structural purposes for which preservative treatment is required.
This report is the fifth (and final) combined data report in a series of reports containing constant bending, tension and compression test results, prepared annually in partial fulfilment of the requirements of a Forestry Canada/Forintek Canada Corp. contract.
A database has been developed to support the expanding use of glulam in non-residential applications. The increase in the use of glulam requires high-value laminating lumber. Other wood products such as purlins and sheathing material usually are also required when glulam members are used in structure. The database contains test results on laminating lumber grades, finger joints, and 14t-E and 12c-E grade spruce/lodgepole pine/Jack pine glulam members, and theoretical and experimental results on glulam trusses with punched metal plate joints. This database is expected to provide the basis for reliability-based design values for glulam in the 1994 edition of the Canadian Engineering Design Standard for Wood (CSA-O86.1). It also makes possible a new glulam application, metal plated glulam trusses. It is anticipated that the engineering design community, glulam industry, laminating lumber producers, wood truss fabricators, and metal truss plate manufacturers will benefit from the technical information developed in this project.
The design procedures for compression perpendicular-to-grain (C-perp) loading in the Canadian Engineering Design in Wood code (CAN/CSA-O86.1-M89) needs to be rationalized to eliminate the inconsistencies in design values and design procedures. This report focuses on developing the data necessary for removing the differences between the C-perp design procedures contained in the glued-laminated timber and the sawn lumber sections. The report presents a description of the ramp and constant load tests on spruce/pine and Douglas-fir wood samples, as well as summaries of data collected to date.