This publication characterizes nine commercial tree species of Alberta. Included are descriptions of the range and volume of each species, their wood properties, and present and potential manufacturing uses.
Changes to the Canadian timber engineering codes over the last 10 years have made it necessary for the wood truss industry to update the wood truss design procedures. The Truss Research Project was established to assist the truss industry to resolve some of the issues arising from the code changes. While most of the issues deal with the analysis of metal plate connected trusses and are therefore specific to the truss industry, some issues that deal with the fundamental strength properties of lumber apply to other engineered timber construction. One area that requires research is the strength of lumber under combined bending and axial loading conditions. A program to model the within-member strength variations of lumber is underway at the University of British Columbia. The purpose of this Forintek project is to develop equipment that can test lumber under combined bending and axial loads. This equipment will be used to validate the lumber strength model. The equipment to test lumber under bending and axial loading has been developed. This report presents a discussion of the equipment specifications and some of the limitations of the equipment identified to-date. The combined loading tester for lumber is currently undergoing verification and trial testing. It will be ready for use in the 1995/96 fiscal year.
To document the current state of sawing performance in Canadian sawmills, a survey was carried out in 47 mills located in the major lumber producing regions of Canada: B.C., Alberta and Quebec. The survey was restricted to sawmills producing softwood lumber products, and to band and circular saws used for primary and secondary breakdown. Data characterizing sawing performance, as well as detailed information on saw and machinery specifications, were collected during visits to each participating sawmill. The results of the survey are presented in this report. Detailed specifications are given for band and circular saws, and sawing performance levels are discussed. The results of the survey show that considerable opportunities exist for improving the performance of both band and circular saws. The large range in saw kerf widths identified in the survey indicate that lumber recovery could be significantly improved by reducing kerf to the levels of the best machines. The performance of these machines demonstrates that thin kerf widths can be achieved while high production rates and small sawing variation are maintained. Specifications for the thinnest kerf machines are presented in the report and opportunities for improving sawing performance levels are also discussed. This report will interest sawmill managers, sawfilers and other mill personnel who want to know how the sawing performance of their mill compares to that in similar mills included in the survey.
Higher bearing strength values for Hem-Fir, where justified, will allow designers to realise the full strength potential of the lumber. Machine stress rated (MSR) lumber would benefit the most from an increase in the Hem-Fir bearing strength. Although there are few Hem-Fir MSR lumber producers, it is anticipated that given the recent or planned increase in installed kiln capacity on the west coast, more mills will be considering producing MSR lumber. Acceptance of Hem-Fir MSR lumber in the marketplace will depend on the design values assigned to Hem-Fir MSR lumber. The objective of this project is to establish characteristic bearing strength values for the Hem-Fir species group in CSA O86.1 and progress to date is described.
The benefits of using sodium borates as a wood preservative against a variety of insects and fungi have been long known. On the other hand, sodium borates are leachable and have an adverse effect on the mechanical properties of composite wood panels. In a previous study ( ), a pilot plant trial on sodium borate-treated OSB was carried out and commercial size panels were subjected to a numbers of tests, e.g., mechanical evaluation, fire, termites and decay resistance. In this study, efforts have been made to improve the mechanical properties and reduce leach out behavior of the borate-treated panels.
Ten series of experimental panels were prepared to evaluate the effect of zinc borates (BoragardRZB) on the properties of OSB panels. Polyethylene glycol was used as the flowing agent. In the first five series, treated panels were bonded with phenol formaldehyde (PF) novolac-type resin while resole PF was used in the second five series. The mechanical properties of panels, treated with zinc borate and bonded with resole PF, were found to comply to the CSA requirements. Panels made with novolac PF and treated with 1% and 2.5% borate met all the CSA requirements, except MOR after a two-hour boil test. It should be noted, however, that the 5% borate-treated panels had excellent results in MOR after the same boil test. Creep tests results showed no evidence that borates will have any adverse effect on the long term performance of treated panels. The results of leaching tests have suggested that BorogardRZB treated panels can be used in an unprotected environment without any significant reduction in protection. Decay tests have shown that treated panels were not subject to attack by Gloeophyllum trabeum or Coriolus versicolor. Weight losses for treated panels were under 1% and no fungal growth was observed. Resistance to Formosan termite attack is being conducted in field tests conducted in Hawaii. Complete test results are expected by 1997 at which time a supplementary report will be prepared.