Design rated oriented strandboard in CSA standards

Abstract

The 1994 edition of CSA (Canadian Standards Association) Standard 086.1 "Engineering design in wood" includes, for the first time, specified strength and stiffness for design rated oriented strandboard (OSB). Design rated OSB panels are manufactured in accordance with the new CSA Standard 0452. In this paper, the results of the short-term (1–10 min) test data which led to the establishment of the three rating grades of Type 1 (standard) design rated OSB are presented. In addition, factors that may affect the classification such as panel thickness and orientation are discussed. Key words: OSB, waferboard, structural panels, wood.

Planar shear moduli of rigidity of an oriented strand board from bending and shear tests

“…However, the average values of planar shear modulus of rigidity in the major and minor axes, Gxz and Gyz, respectively, for the OSB test panel (51 -72 N/mm 2) are low compared to other published values of Gxz and G yz that are typically in the range from 150 to 200 N/ram [4,6]. The relatively low shear stiffnesses from the bending and shear tests are related to the density distribution through the thickness, the relative layer thickness, resin distribution and degree of strand orientation in the test board.…”

“…Numerous studies of solid wood have shown that there is strong correlation between the bending modulus of elasticity and planar shear modulus of rigidity [9]. In the case of OSB, such a correlation has so far not been shown [6,7]. However, if there is a correlation, linear or non-linear, between the planar shear modulus of rigidity and the planar shear strength, the planar shear modulus of rigidity determined from bending test can roughly give an indication of the planar shear strength.…”

“…Another appeal of a bending test is that it simulates the complex stress-strain state through the thickness of orthotropic panels, such as oriented strand board, when used in flooring and roofmg. Extensive data have been produced for the bending, tensile and compressive strengths and stiffnesses of oriented strand board [5,6]. However, data for the planar shear moduli of rigidity of OSB are sparse [4][5][6].…”

“…Extensive data have been produced for the bending, tensile and compressive strengths and stiffnesses of oriented strand board [5,6]. However, data for the planar shear moduli of rigidity of OSB are sparse [4][5][6]. Bending and direct planar shear tests have been used to determine the planar shear moduli of rigidity of an oriented strand board.…”

Assessment of test-piece size for punching shear capacity of orthotropic panels: Case study of OSB

“…The test results reveal that the ratio of major to minor axes of the failed envelope is about 1.3, and is of the same order as the levels of orthotropy in planar shear rather than the levels of orthotropy in bending MOE and strength of 2.7 and 1.7 respectively. The values of the planar shear properties of other OSB [9,10] show that the levels oforthotropy in planar shear strengths and MOEs range typically from 0.7 to 1.3. Assuming that the ratio of major to minor axes of the failed elliptical envelope is of the same order as the level of orthotropy in planar shear, then the shape or eccentricity of the elliptical failure envelope for other types of OSB panels can be predicted.…”