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Increasing adhesive choices in engineered wood products that meet market requirements

https://library.fpinnovations.ca/fr/permalink/fpipub41381
Auteur
Pirvu, Ciprian
Date
March 1907
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Collaborateur
Alberta Forestry Research Institute
Date
March 1907
Genre du document
Research report
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Building Systems
Sujet
Materials
Adhesives
Série
W-2481
Localisation
Vancouver, British Columbia
Langue
English
Résumé
Test results for three representative adhesives were obtained for use in the development of a proposed standard for limited moisture exposure (CSA O112.10). The adhesives tested were an emulsion polymer isocyanate (EPI), a polyurethane (PUR) and a melamine-urea formaldehyde with 40% melamine resin content (MUF40). Currently, EPI and PUR are used for I-joists and fingerjoined lumber. MUF40 was included in the study as a non-conforming adhesive. The range of performance of these adhesives, along with that of melamine formaldehyde (MF) and polyvinyl acetate (PVA) evaluated in a previous study, is baseline information used in defining acceptable performance levels for adhesives undergoing block shear tests required in the proposed standard. Specimens in this study were evaluated under five test conditions: dry, vacuum-pressure wet or re-dried, and three-cycle boil-dry-freeze wet or re-dried. Dry and re-dried test conditions are the proposed test protocols for the draft CSA O112.10 standard. In terms of shear strength and percentage of wood failure, EPI and MUF40 met the requirements of CSA O112.9 for the dry test condition, and PUR did not. The following block shear test requirements are recommended for CSA O112.10, based on the 95% lower confidence limit of the EPI test results, and structured to be analogous to the requirements of CSA O112.9:
Median dry shear strength = 10 MPa (1450 psi) (adopted from CSA O112.9);
Vacuum-pressure re-dried median shear strength = 7.4 MPa (1070 psi);
Three-cycle boil-dry-freeze re-dried median shear strength = 4.4 MPa (640 psi);
Median percentage wood failure = 85% for all the proposed tests (adopted from CSA O112.9); and
Lower quartile percentage wood failure = 75% for all the proposed tests (adopted from CSA O112.9). The above requirements will be discussed in the CSA Task Group, which will eventually make recommendations to the CSA Standards Committee.
Adhesion and Adhesives - Composite Materials
Documents
Moins de détails

State-of-the-art report on fibre reinforced polymer (FRP) utilization in wood products

https://library.fpinnovations.ca/fr/permalink/fpipub41302
Auteur
Pirvu, Ciprian
Date
June 2004
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Date
June 2004
Genre du document
Research report
Description physique
35 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Advanced Wood Materials
Sujet
Materials
Série
W-2073
Localisation
Vancouver, British Columbia
Langue
English
Résumé
Fibre-reinforced wood systems are light, strong, stiff composites that can efficiently replace larger wood members and can be relied on to provide consistent mechanical properties. This report is an introduction to fibre-reinforced wood systems for members of the Canadian wood products industry. It provides the motivation for reinforcing wood with synthetic fibres, and surveys the choice of materials and their uses. Numerous examples of current applications are discussed to demonstrate the strong and weak points of various approaches and examine the durability and management of fibre-reinforced wood products, as well as to indicate opportunities that exist for the Canadian wood products industry. This report is intended to be a useful reference for the Canadian wood products industry, and assist future developments in structural and non-structural applications of fibre-reinforced wood products.
Composite materials - Durability
Fibres
Board products - Materials used
Documents
Moins de détails

Structural performance of wood diaphragms with thick panels

https://library.fpinnovations.ca/fr/permalink/fpipub37881
Auteur
Pirvu, Ciprian
Date
March 2008
Genre du document
Research report
Domaine
Sustainable Construction
Auteur
Pirvu, Ciprian
Collaborateur
Canada. Canadian Forest Service.
Date
March 2008
Genre du document
Research report
Description physique
70 p.
Secteur
Wood Products
Domaine
Sustainable Construction
Champ de recherche
Building Systems
Sujet
Mechanical properties
Design
Building construction
Série
Canadian Forest Service No. 13
4636
W-2525
Localisation
Vancouver, British Columbia
Langue
English
Résumé
Wood design standards in Canada and the United States provide design values for floor and roof diaphragms with sheathing thickness ranging from 9.5 mm (3/8 in) up to 18.5 mm (3/4 in), that are supported by joists spaced less than 610 mm (24 in) on centre. This range of sheathing thicknesses is adequate for housing and small buildings, but for large non-residential structures, diaphragms with thicker sheathing and wider joist spacing may be more appropriate. This paper includes the findings of a study aimed at providing research information suitable for implementing design values for diaphragms with thick sheathing in the North American wood design standards. Results from quasi-static monotonic tests on fifteen full-scale 7.3 m (24 ft) long by 2.4 m (8 ft) wide diaphragms framed with 38x191 mm or 38x235 mm (nominal 2x8 and 2x10, respectively) solid sawn lumber or laminated strand lumber and sheathed with plywood or oriented strand board are discussed. A numerical model was developed using the finite element method. The basic properties of the sheathing, framing members and nailed connections were implemented in the model to replicate the structural behaviour of the diaphragms with thick panels. The numerical model was successfully validated against the experimental data. The shear resistance values for the diaphragms with thick panels tested in this study were calculated. The model may be used to interpolate between various diaphragm configurations and calculate shear resistance values for other configurations of diaphragms with thick sheathing. In the long run, it is hoped that the use of thicker sheathing will enable the use of structural systems that are cost effective for wider joist or beam spacing than systems made with dimension lumber and traditional sheathing thickness. The experimental data and the model developed in this project will be used to develop proposals for implementation of wood floor and roof diaphragms with thick panels in the Canadian and United States wood design standards.
Diaphragms - Strength
Building construction - Design
Documents
Moins de détails