Laminated timbers, structural

In order to establish control values for the adhesives formulated using tannins, the initial work was done with phenol-resorcinol-formaldehyde (PRF) or resorcinol-formaldehyde (RF) resins on both surfaces, but modified for the honeymoon principle. The PRF resin chosen for this work was Borden s resin LT-75 with Borden s hardener FM-260. The RF resin used for a comparison was Chembond s RF-900. These resins have been used for wood gluing in the United States for more than two decades, especially for the manufacture of structural laminated timbers. 

AITC (1990) Standard for preservative treatment of structural glued-laminated timber. AITC 109. American Institute of Timber Construction, Englewood, Colorado AITC (2001) Standard appearance grades for structural glued-laminated timber. AITC 110. 

Anonymous (1996) Best Management Practices for the Use of Treated Wood in Aquatic Environments. USA version. Western Wood Preservers Institute, Vancouver, BC ANSI/AITC (2002) Structural glued laminated timber. ANSEAITC A190-1. American National Standards Institute and American Institute of Timber Construction, Englewood, Colorado... 

Schaffer EL, Jokerst RW, Moody RC, Peters CC, Tschemitz IL and Zahn JJ (1972) Feasibility of producing a high-yield laminated structural product general summary. USDA, Forest Service, Forest Products Laboratory, Research Paper FPL 175 Schaffer EL, Jokerst RW, Moody RC, Peters CC, Tschemitz IL and Zahn JJ (1977) Press-lam progress in technical development of laminated veneer structural products. USDA, Forest Service, Forest Products Laboratory, Research Paper FPL 279 Schaffner RD (1991) Drying costs a brief introduction. In Australian Timber Seasoning Manual. Australian Furniture Research and Development Institute, Launceston, Tasmania... 

CEN/TC 124 Timber Structures , SN EN 408 2003 Timber structures — construction timber and glued laminated timber — Determination of some physical and mechanical properties, SIA Schweizerischer Ingenieur- und Architektenverein Zurich, Switzerland (2003). 

One particular structural application of adhesives is in the manufacture of glued laminated timber or glulam members. This is normally manufactured by glueing together at least four planks of timber with their grain essentially parallel. The laminations are usually machined from 38 or 50 mm thick timber although thinner sections may be necessary in the production of curved members. End... 

Useful mono-material structural elements may be formed by bonding together a number of individual pieces of the same material. Glued laminated timber (glulam) members as described in Chapter 7 represent a development in which structural elements of large cross-section may be created. Adhesive bonding, as opposed to mechanical fastening, leads to reduced stress concentrations as well as the elimination of joint slip. The same principle may be applied to other materials where appropriate, such as aluminium extrusions and... 

EN 14080 Timber structures. Glued laminated timber. Requirements. EN 14374 Timber structures. Structural laminated veneer lumber (LVL). Requirements. 

EN 408 Timber structures. Structural timber and glued laminated timber. Determination of some physical and mechanical properties. 

The adhesives are used in the construction industry that includes residential and commercial buildings, roads, bridges, and other elements of the infrastructure. They are utilized for manufacturing a number of structural products, such as softwood plywood, laminated timbers, laminated paper-based panels, etc. More recently, adhesives have been used to replace mechanical fastenings in the assembly operation of building construction. These are called construction adhesives. The compounds must be capable of producing adequate bonds in poorly fitting joints with thick and variable thickness bondlines.t " ... 

Thermomechanical analysis (TMA) was used to investigate the curing behavior of resorcinol-formaldehyde (RF) and phenol-resorcinol-formaldheyde (PRF) adhesive resins used for structural glued laminated timber and veneer lumber, Samples were heated from room temperature... 

Structural Adhesives for Fingeijointing Lumber. A recent standard detailing the testing of finger joints when used as end joints in structural glued, laminated timbers (see also D-2559 in wood adhesive specifications). 

The joining of wood by adhesives is widely used in many fields of application. This comprises structural joints, glued-laminated timber, and coatings. In industrial processes, wood is structurally connected by formaldehyde-containing melamine or phenol resorcin resins which cure by polycondensation. Due to the very thin adhesive layers and the minimized formaldehyde content, the expected incorporation into the surrounding air is considerably less than the specified thresholds. In manually operated applications, dispersions of acrylates and polyvinyl acetate as well as urethanes are usually used to bond wood (Richter and Steiger 2005). 

Developments in glued laminated structures and panel products such as plywood and chipboard raises the question of the durability of adhesives as well as wood. Urea-formaldehyde adhesives are most commonly used for indoor components. For exterior use, resorcinol adhesives are used for assembly work, whilst phenolic, tannin and melamine/urea adhesives are used for manufactured wood products. Urea and casein adhesives can give good outdoor service if protected with well-maintained surface finishes. Assembly failures of adhesives caused by exudates from some timber species can be avoided by freshly sanding the surfaces before glue application. 

IV Combustible construction commonly referred to as heavy timber, mill or plank-on-timber Exterior and interior bearing walls are of noncombustible construction and 2 hour rated Interior structural members, floors and roofs are solid or laminated wood and meet minimum dimensional criteria... 

Wood and biomass are raw materials (Figure 9.4.1) for traditional building products like sawn timber, prefabricated timber elements and systems as well as wood-based materials in the form of boards (e.g. particle- and fibreboards), but also as construction elements from glued products like laminated beams, plywood, oriented structural boards or laminated veneer lumber. ... 

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