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.
The Fastenings Subcommittee of the CSA Technical Committee (TC) on Engineering Design in Wood has identified a need to extend the use of glulam rivet connections to sawn timber with appropriate service condition factors, and to investigate the effect of plate thickness on joint capacity. A total of 640 lateral resistance tests on glulam rivet/sawn timber specimens were performed. The load carrying capacity of glulam rivet/sawn timber connections was determined in rivet yielding mode. Preliminary data analysis on the effect of species, loading type and direction, environmental conditions, density, waiting period between assembly and test, pre-drilling, and plate thickness on the load carrying capacity was performed. In the 1992/93 fiscal year, the remaining testing will be completed, findings will be discussed with the members of the Glulam Rivet Task Group, and then submitted to the Fasteners Subcommittee of CSA TC on Engineering Design in Wood.
11 lodgepole pine study sites were selected in British Columbia, and Alberta for a study of basic wood properties. At each site 20 trees were selected, felled, and sampled at five height levels for relative density, fiber length, longitudinal shrinkage, lignin and extractives content determinations. This report presents wood relative density trends, stem sizes, and juvenile-mature wood distribution in 80 to 100 year-old lodgepole pine stands which grew under various stocking densities (500 - 2300 stems/hectare). In all three diameter classes sampled, a high degree of intra-ring density uniformity was evident, as low density earlywood and high density latewood ranged between 0.30 to 0.60 for western-red-cedar and Douglas-fir 0.25 to 0.80. This density homogeneity contributes to excellent machinability and veneer peeling qualities. When lodgepole pine trees of similar environment were compared at equal age and equal height level there was no relationship between growth rate and relative density. Comparatively low density wood in the large diameter trees was the result of normal physiological influence of the live crown. As crown dominance is reduced, through higher stocking densities, wood density is enhanced in the lower bole but at the expense of log size. And herein lies the paradox because both the solid wood and pulp and paper industry experts believe that industry will maximize profit by planning to grow, harvest, and process larger, rather than smaller, trees.
There is very little information about basic wood properties for yellow-cypress. This report presents wood relative density trends, stem sizes, heartwood-sapwood distribution, and longitudinal shrinkage characteristics in 13 old-growth, 10 second-growth, and 20 in off-site (out of its natural range) plantation-grown yellow cypress trees. Based on these comparisons and previous work at Forintek, yellow-cypress wood appears to be the most homogenous commercial softwood species in Canada. In terms of wood relative density yellow-cypress had comparatively high-density juvenile core-wood. The old-growth resource average density of 0.42 was met or surpassed in all three age classes. Yellow-cypress resource managers and the users of yellow- cypress wood can be confident that wood quality can be maintained in second-growth stands. Wood density comparisons with other softwoods and Japanese hinoki demonstrated why yellow-cypress wood is an excellent substitute for hinoki in terms of product properties.
The objective is to broaden the market for sheathing panels by establishing shear strength values for the design of floor and roof diaphragms using 18.5mm and 20.5mm thick plywood panels. As a result of an emergency no work was done on this project.
Forest resource issues in Canada vary by region, but in general, the forest industry is faced with a continuing decline in the volume and quality of available timber. Doing more with less will be the key to profitability. Changing, and increasingly fragmented markets, mean that industry must have improved information descriptive of the end- product potential of the current forest resource. Rapidly increasing expenditures on stand management make it imperative that governments and industry be provided with information describing how present silvicultural practices will impact on future wood quality. In some regions, where managed forests are approaching rotation age, information is needed to help industry examine its options for harvesting, processing and marketing this emerging resource. Forintek Canada Corp. has established a national program of resource assessment to meet the need for information that will permit the consideration of wood quality in processing, marketing and stand management decisions. The objective of this problem analysis was to ensure that resource characterization research is structured such that results of interdisciplinary work, done within Forintek or by cooperating agencies, can be successfully integrated to provide comprehensive answers to resource utilization and stand management questions. This report describes the development of the resource assessment research program, the goals established for it and the framework within which they will be accomplished.
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.
The objective of the program is to catalyze the development of boron as an environmentally acceptable chemical treatment and improve process technology to produce a boron-treated lumber product. There is a need for low environmental impact wood preservatives, particularly for the residential market. Although the hazards associated with treated wood may be negligible, the public perception of potential hazards may be sufficient to proscribe the future use of the present preservatives. Boron is an environmentally benign preservative which has been used for many years in New Zealand and Australia and has started to be used in the U.S.A. but is not yet used in Canada. There is a potential market for termite-proof wood for southern Ontario and boron promises to be a suitable candidate. Opportunities also exist in overseas markets for boron treated lumber provided that a rapid and cost effective diffusion process can be developed. Western softwoods, which are naturally wet species, particularly lend themselves to diffusion treatments with boron. Despite there being a good body of scientific literature available on borate treatment of wood there is a lack of basic technical knowledge on borate treatment of Canadian woods. This project seeks to address this need.
Methods for the analysis of boron in wood were reviewed and one, a method in which base titration of a mannitol/boron complex is done, was chosen for possible routine use. Method parameters were tested and the stages were modified to arrive at a routine which can determine boron content in wood within 5% accuracy. Hot water leaching of chip samples, 2.54 x 2.54 cm x 2 to 3 mm thick, of wood which has been given borate/antisapstain treatment is better than 95% efficient within four hours; this is as efficient as a ten-cycle extraction on a soxhlet apparatus. Using an automatic titrator, analysis for boron is done by titrating a mannitol complex of the boron in the extract. The simplicity, low expense, speed, and accuracy of this routine give it the advantage over several other methods. The aqueous extracts of wood, the mannitol reagent, and secondary components of boron treating formulations can all add to the apparent boron content of the wood sample; these factors are variable but generally total about 8 *g boric acid equivalent per cm2 of wood surface. The method is also suitable for the analysis of boron in heavily (preservative) treated wood.
Communiqué Technique No: Routes et Ponts ; CTRP 30
Les opérations forestières en bordure de cours d'eau doivent être conformes aux lois provinciales mises en place pour protéger cetter ressource fragile. Les traverses de cours d'eau sont généralement régies par des règlements concernant les dimensions des structures, la protection des rives et enfin la migration des poissons.