This addendum completes the presentation of the data and research findings for the project entitled "Development of a high performance OSB panel." Most of the short-term test results and preliminary long-term creep data were summarized in a previous report (Project No. 38-43-M-410) which was submitted to the Canadian Forest Service. This addendum to that report includes new data on rolling shear, revised data on shear-through-thickness, and creep data collected during a load duration of nine months, followed by a three-week creep recovery. In addition, the effects of parameters such as strand length and climatic conditions on the engineering properties are discussed for OSB, waferboard, and plywood panels. Utilization of long strands improved the majority of the properties of OSB panels produced with commercial strands. This improvement, however, was not observed for the OSB panels produced with laboratory strands.
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 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.
Although the code provisions for dealing with the long-term structural performance of wood products are based solely on tests on solid sawn lumber, these provisions are currently applied to composite or engineered wood products. There are concerns among code writers that some composite wood products may not necessarily exhibit the same long-term behaviour as lumber. In order to address these concerns, a standard test needs to be developed for assessing the long-term performance of such products. Although test protocols are available from previous studies, the extensive testing originally conducted for lumber was judged impractical for composite wood products. This is because of the proprietary nature of composite wood products and the desire to allow manufacturers, whenever possible, the ability to alter a product to suit the available fibre resource and market demands. These conditions are particularly true during initial product development where rapid and cost effective assessment procedures are needed. An American Society for Testing and Material (ASTM) subcommittee was therefore established to prepare an appropriate consensus standard. This project is designed to allow Forintek staff to participate in that process as well as develop the baseline performance data for lumber, which the composite product performance will be compared to, in the proposed ASTM standard. The members of the two Task Groups of the ASTM Section D07.01.04, prepared a draft of the "Standard Specification for Evaluation of Load Duration and Creep Effects for Wood Products". This draft included a simple verification method, and more extensive probabilistic method. The verification method requires the producer to demonstrate that his product has equal or better long-term performance than lumber, while the probabilistic approach requires producers to develop extensive test data and then perform analysis to quantify the DOL and creep factors. The verification test portion of the draft standard has been applied to a sample of lumber to obtain the baseline performance data at low load levels. Results showed that this group fulfilled the requirements stipulated in the verification method in the draft ASTM standard. The ASTM draft standard has been balloted at the section level. Due to the negative votes received on the draft standard, the ballot was withdrawn. A new draft is planned to be balloted in the 1997/98 fiscal year. In the meanwhile, some representatives of the structural composite lumber industry have proposed to incorporate the verification portion of the draft standard into the ASTM Standard for Structural Composite Lumber. They prepared a paper including this approach, and compared the DOL performance of some composite lumber products against the lumber results provided to them by Forintek and the USFPL. They found that the verification method can be used to check the equivalency of the long-term structural performance of two composite lumber products. The Canadian Standards Association Technical Committee on Engineering Design in Wood has accepted the methodology given in this paper.