FPInnovations Wood Products Division

Vancouver, Canada

FPInnovations Wood Products Division

Vancouver, Canada
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Ni C.,FPInnovations Wood Products Division | Chui Y.H.,University of New Brunswick
World Conference on Timber Engineering 2012, WCTE 2012 | Year: 2012

North American lateral design load resistances of shearwalls and diaphragms are derived empirically from test data. Because of the high cost associated with the testing of full-scale shearwalls and diaphragms, the available combinations of various framing materials, sheathing thicknesses and fasteners are limited in the timber design codes. This has limited the options available to designers and has stifled the use of innovative materials for these assemblies. In this paper, the available analytical models and approaches for determining shear resistances of shearwalls and diaphragms are reviewed and compared. Procedures for calculating the design values of shearwalls and diaphragms with commonly accepted construction details are proposed. Factors, such as nail spacing and sheathing buckling, that could potentially reduce the lateral load resistances and proposed approaches to address these issues in a mechanics- based design method are discussed. Requirements for joint ductility are considered to ensure that the same force modification factor assigned for shearwalls and diaphragms in the design code can be used. Comparison shows that the predicted resistances using the proposed calculation procedures are in good agreement with the current design values in the Canadian timber design code CSA 086.

Asiz A.,University of New Brunswick | Chui Y.H.,University of New Brunswick | Doudak G.,University of Ottawa | Ni C.,FPInnovations Wood Products Division | Mohammad M.,FPInnovations Wood Products Division
Procedia Engineering | Year: 2011

The main objective of this paper is to investigate the contribution of plasterboard finishes made of gypsum wall board (GWB) to the structural performance of multi-storey light wood frame building (LWFB) subjected to earthquake load. Four- to six-storey buildings were analysed in this study. Computer software, SAPWood, developed to analyze LWFB subjected to actual earthquake motions was used. Two cases were considered in the analyses. The first one was a reference case where all shear walls are fabricated with wood-based sheathing panels only. The second case was buildings with walls fabricated with wood-based sheathing panels plus GWB. All shear wall hysteretic properties for both cases (with and without GWB) and inter-storey (hold-down) connections were derived from detailed numerical modeling of wall sub-systems available in the SAPWood database. The buildings were subjected to a major earthquake ground motion excitation, and the ground motion was scaled until failure in the components (walls or hold-down connections) or excessive inter-storey drift was reached. Main outputs that were used as comparison between the two cases included natural period, maximum storey shear force and drift, and individual wall responses (force and deformation). Specific attention was paid to how the applied forces are distributed between the different types of wall panels i.e. wood-based and gypsum-based.

Al Mamun A.,University of Ottawa | Doudak G.,University of Ottawa | Ni C.,FPInnovations Wood Products Division | Mohammad M.,FPInnovations Wood Products Division | And 2 more authors.
Proceedings, Annual Conference - Canadian Society for Civil Engineering | Year: 2011

Wood portal frame systems have been identified by engineers and builders as a viable option to meet the increasing demand for larger structures, wider openings, and open concept design. In order to develop construction details for portal frames so that they can be integrated into a light wood frame structure containing wood shear walls, there is a need to better understand the behavior of such systems. This study has two main goals: to investigate the behavior of light wood based portal frames and improve on their behavior so that they can be used as a substitute to light frame shearwalls with wood sheathing panels; and to develop high capacity portal frame bracing systems for use in mid-rise wood construction. Based on the preliminary test results and numerical analysis, it was found that the wall height has a significant impact on the performance of portal frame walls; for walls with different types and locations of metal strap, it is found that the tensile strength of metal straps has the highest impact on the lateral load capacities of portal frame walls; and that the walls with sheathing attached on both sides of the framing have approximately 30% higher lateral load capacities and stiffness than the walls with sheathing attached on one side of the framing. The next phase of the research program will be focused on developing other alternative high-capacity bracing systems that can be used in mid-rise timber construction.

Gao Z.,Northeast Forestry University | Wang X.-M.,FPInnovations Wood Products Division | Wan H.,FPInnovations Wood Products Division | Brunette G.,FPInnovations Wood Products Division
BioResources | Year: 2011

The bark of black spruce was thermo-mechanically refined and used to manufacture binderless bark-based fiberboard with various pressing temperatures, times, and panel structures in order to utilize an abundant bark resource for a better value-added application. The test results indicated that it is technically feasible to manufacture binderless fiberboard with refined black spruce bark through self-bonding under elevated temperatures over a reasonable period of pressing time. Binderless bark-based fiberboards with a homogeneous structure had very poor flexural properties due to the poor strength of bark itself; however, by using a sandwich structure with 30wt% wood fiber in the surface layers and 70wt% bark in the core layer it was possible to sufficiently improve panel flexural properties so that the manufactured binderless bark-based fiberboards was able to meet the mechanical property requirements of 115-grade fiberboard according to ANSI A208.2 (2009). Refining conditions had a great impact on the mechanical properties of binderless bark-based fiberboard.

Janin A.,University of Toronto | Riche P.,University of Québec | Blais J.-F.,University of Québec | Mercier G.,University of Québec | And 2 more authors.
Environmental Technology (United Kingdom) | Year: 2012

This study explores the performance of a counter-current leaching process (CCLP) for copper extraction from copper azole treated wood waste for recycling of wood and copper. The leaching process uses three acid leaching steps with 0.1M H2SO4 at 75C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5amperes (A) for 75min. Ten counter-current remediation cycles were completed achieving94% copper extraction from the wood during the 10 cycles; 80-90% of the copper was recovered from the extract solution by electrodeposition. The counter-current leaching process reduced acid consumption by 86% and effluent discharge volume was 12 times lower compared with the same process without use of counter-current leaching. However, the reuse of leachates from one leaching step to another released dissolved organic carbon and caused its build-up in the early cycles. © 2012 Copyright Taylor and Francis Group, LLC.

Bustos C.,University of Bío Bío | Hernandez R.E.,Laval University | Beauregard R.,Laval University | Mohammad M.,FPInnovations Wood Products Division
Maderas: Ciencia y Tecnologia | Year: 2011

Efficiency of finger-joints in the Engineered Wood Products is key to the performance of these products. The aim of this research work was to evaluate, by scanning microscopic analysis, the effect of end pressure on the performance of horizontal finger-joint of black spruce (Picea mariana (Mill.) B.S.P) specimens. A feather joint configuration glued with an isocyanate type of adhesive cured at room-temperature was used. The finger-joints were machined at a feed rate of 18.3 m/min, rotational speed of 3500 rpm, and at a feed per knife (chip-load) of 0.86 mm. A single-face glueline application was used at a spread rate of 110 g/m2. The curing time was kept at 24 hours. Six end-pressure levels ranging from 1.38 MPa to 4.82 MPa applied for 20 seconds were investigated. Results showed that cell depth damage increased as end-pressure increased. Joints also showed formation of some air bubbles within the glueline which lead to a reduction in their tensile strength.

Schneider J.,University of British Columbia | Stiemer S.F.,University of British Columbia | Tesfamariam S.,University of British Columbia | Karacabeyli E.,University of British Columbia | Popovski M.,FPInnovations Wood Products Division
World Conference on Timber Engineering 2012, WCTE 2012 | Year: 2012

Wood-frame is the most common construction type for residential buildings in North America. However, there is a limit to the height of the building using a traditional wood-frame structure. Cross-laminated timber (CLT) provides possible solutions to mid-rise and high-rise wood buildings. CLT offers many advantages such as improved dimensional stability, a quicker erection time and good performance in case of fire. In order to introduce the cross-laminated timber products to the North American market, it is important to gain a comprehensive understanding of its structural properties. This paper focuses on the seismic performance of CLT connections. Over the last few years FPInnovations of Canada has conducted a test program to determine the structural properties of CLT panels and its application in shear walls. The test program comprised of more than 100 connection tests which followed the loading procedures of CUREE and ISO test protocols as specified in ASTM Standards ASTM E 2126-09 (2009). These tests were performed parallel and perpendicular to the grain of the outer layer, respectively. The impact of different connections on the seismic performance of CLT walls was investigated in a second phase on full size shearwall. CLT panels are relatively stiff and thus energy dissipation must be accomplished through the ductile behaviour of connections between different shear wall elements and the connections to the story below. A literature review on previous research work related to damage prediction and assessment for wood frame structures was performed. Different approaches for damage indices were compared and discussed. This paper describes how the energy-based cumulative damage assessment model was calibrated to the CLT connection and shear wall test data in order to investigate the damage under monotonie and cyclic loading. Comparison of different wall set-up provided a deeper insight into the damage estimation of CLT shear walls and determination of the key parameters in the damage formulation. This represents a first published attempt to apply the damage indices to estimate the seismic behaviour of CLT shear walls.

Cai L.,FPInnovations Wood Products Division | Oliveira L.C.,FPInnovations Wood Products Division
Forest Products Journal | Year: 2011

Mills producing spruce-pine-fir (SPF) dimension lumber are required to carry out heat treatment before shipping the lumber to markets. Kiln drying/heat treatment is the most common strategy for drying SPF lumber. Currently there is a question about whether to use air drying before or after heat treatment to improve lumber grade recovery and reduce energy consumption. We tested three drying strategies for spruce/pine and sub-alpine fir lumber: heat treatment followed by air drying (HT+AD), air drying followed by heat treatment (AD+HT), and kiln drying heat treatment alone (KD/HT). Results related to final moisture content uniformity, warp, and drying stress were better when air drying was incorporated in the strategy. The standard deviation of the final moisture content was reduced from 3.9 to 1.3 percent for spruce/pine and from 7.2 to 3.1 percent for sub-alpine fir. Warp was reduced by 27 to 42 percent for spruce/pine and 14 to 41 percent for sub-alpine fir. Using the prong tests, drying stress was reduced by 23 to 60 percent for spruce/pine and 35 to 71 percent for sub-alpine fir. Improved final moisture content uniformity, less warp, and lower drying stresses were obtained for the lumber tested under the HT+AD strategy compared with the AD+HT strategy. © 2011 Forest Products Society.

Al Mamun A.,University of Ottawa | Doudak G.,University of Ottawa | Ni C.,FPInnovations Wood Products Division | Mohammad M.,FPInnovations Wood Products Division
Proceedings, Annual Conference - Canadian Society for Civil Engineering | Year: 2012

Shear walls have been successfully used to meet the design requirements in building codes for both engineered wood buildings and those designed based on prescriptive requirements to ensure that buildings have adequate lateral load resistance to wind and/or seismic loads. However, there is a need for lateral load resisting systems that can be used where limited space is available for braced walls, for example, in the case of a multi-car garage or open space design concepts. Existing knowledge from corner and full scale tests on portal frames using conventional framing methods and connection details show that the moment transfer capacity of header and narrow braced wall segment is the weakest link in such systems and is detrimental to the lateral load capacity of a portal frame. This prompted a research effort with focus on investigating and improving the moment carrying capacity of the corner in such portal frames. In order to develop portal frame with higher lateral load capacity, the MIDPLY shear wall concept has been used in a series of corner joint tests. The corner joint test results will also be used to identify potential optimum corner joint configuration for full scale portal frame tests. In this paper, the behavior and failure modes of MIDPLY portal frame corner joints has been discussed.

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