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Strength grading of wet Norway spruce side boards for use aslaminations in wet-glued laminated beams

Oscarsson, Jan; Olsson, Anders; Johansson, Marie; Enquist, Bertil and Serrano, Erik LU (2010) Final conference of COST action E53 In The Future of Quality Control for Wood and Wood Products
Abstract
<p>Strength grading of Norway spruce side boards in the wet state was investigated. For a sample of 58 boards of dimensions 25×120×3000 mm3, density and dynamic modulus of elasticity in the axial direction, MOEdyn, were determined in the wet state. The boards were then split into two parts and the procedure of determining MOEdyn was repeated both before and after the boards were dried to a target moisture content of 12 %. Tensile strength of the split boards was finally measured and its relation to MOEdyn for both split and unsplit boards determined. The investigation also included an evaluation of a so called reversed lamination effect on the stiffness caused by the splitting of boards into two parts. The results show that strength... (More)
<p>Strength grading of Norway spruce side boards in the wet state was investigated. For a sample of 58 boards of dimensions 25×120×3000 mm3, density and dynamic modulus of elasticity in the axial direction, MOEdyn, were determined in the wet state. The boards were then split into two parts and the procedure of determining MOEdyn was repeated both before and after the boards were dried to a target moisture content of 12 %. Tensile strength of the split boards was finally measured and its relation to MOEdyn for both split and unsplit boards determined. The investigation also included an evaluation of a so called reversed lamination effect on the stiffness caused by the splitting of boards into two parts. The results show that strength grading of split boards in the wet state could give just as good results as grading performed after drying. The coefficient of determination between MOEdyn in wet and dried states was as high as R2=0.92, and the relation between MOEdyn in the wet state and tensile strength in the dried state, ?t, was of the same order (R2=0.55) as the relation between MOEdyn in the dried state and ?t (R2=0.52). Regarding the reversed lamination effect on the stiffness of split boards, it was found to be of low order.</p> (Less)
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The Future of Quality Control for Wood and Wood Products
publisher
COST
conference name
Final conference of COST action E53
language
English
LU publication?
yes
id
05cd66d4-04ac-4936-8a9c-b6e69f76ea0e (old id 4770382)
date added to LUP
2014-11-07 14:19:51
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2016-04-16 07:17:29
@inproceedings{05cd66d4-04ac-4936-8a9c-b6e69f76ea0e,
  abstract     = {&lt;p&gt;Strength grading of Norway spruce side boards in the wet state was investigated. For a sample of 58 boards of dimensions 25×120×3000 mm3, density and dynamic modulus of elasticity in the axial direction, MOEdyn, were determined in the wet state. The boards were then split into two parts and the procedure of determining MOEdyn was repeated both before and after the boards were dried to a target moisture content of 12 %. Tensile strength of the split boards was finally measured and its relation to MOEdyn for both split and unsplit boards determined. The investigation also included an evaluation of a so called reversed lamination effect on the stiffness caused by the splitting of boards into two parts. The results show that strength grading of split boards in the wet state could give just as good results as grading performed after drying. The coefficient of determination between MOEdyn in wet and dried states was as high as R2=0.92, and the relation between MOEdyn in the wet state and tensile strength in the dried state, ?t, was of the same order (R2=0.55) as the relation between MOEdyn in the dried state and ?t (R2=0.52). Regarding the reversed lamination effect on the stiffness of split boards, it was found to be of low order.&lt;/p&gt;},
  author       = {Oscarsson, Jan and Olsson, Anders and Johansson, Marie and Enquist, Bertil and Serrano, Erik},
  booktitle    = {The Future of Quality Control for Wood and Wood Products},
  language     = {eng},
  publisher    = {COST},
  title        = {Strength grading of wet Norway spruce side boards for use aslaminations in wet-glued laminated beams},
  year         = {2010},
}