Machine strength grading of structural timber: new opportunities for the Italian solid wood and glued laminated timber

Traditionally unreinforced tension-side notches at supports of glued-laminated-timber (glulam) bending members have been designed in Canada assuming shear capacity is reduced in proportion to the square of the residual depth ratio. The origin of that practice lies in World War II era studies in the USA on solid wood members. More recent research in Canada, US, and Europe has focussed on application of linear elastic fracture mechanics (LEFM) methods to such problems, reflecting that such approaches can account for effects of variables other than notch depth ratio. Canadian wood design code CSA Standard 086 “Engineering Design in Wood” first capitalized on availability of LEFM approaches in 1994 by adopting such a method for design of sawn lumber members with tension-side notches at supports. The same was not done then for glulam members because of paucity of supporting test data. That gap has now been filled and the 2014 edition of CSA Standard 086 employs consistent LEFM based design approaches for both sawn lumber and glulam members with tension-side notches. New provisions for glulam recognize influences that notch length and shape, and how laminations in members are fabricated have on member capacities. Discussion here addresses the logic that underpins the new glulam provisions and how application of those provisions impacts design solutions. Overall impact of the new design provisions is to discourage use of relatively large tension-side notches at supports of larger glulam bending members, while not discouraging use of notches in smaller glulam members.

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Physical and mechanical properties of impregnated polystyrene jabon (Anthocephalus cadamba) glulam

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/891/1/012007 ◽

2021 ◽

Vol 891 (1) ◽

pp. 012007

Author(s):

Y S Hadi ◽

E N Herliyana ◽

I M Sulastiningsih ◽

E Basri ◽

R Pari ◽

...

Keyword(s):

Mechanical Properties ◽

Shear Strength ◽

Moisture Content ◽

Physical And Mechanical Properties ◽

Solid Wood ◽

Hot Water ◽

The Other ◽

Modulus Of Rupture ◽

Glued Laminated Timber ◽

Anthocephalus Cadamba

Abstract Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2 and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.

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ANÁLISE DO COMPORTAMENTO DE PEÇAS ESTRUTURAIS DE MADEIRA LAMINADA COLADA COM RESINA POLI-URETANA SUBMETIDAS À COMPRESSÃO AXIAL

Colloquium Exactarum ◽

10.5747/ce.2018.v10.nesp.000160 ◽

2018 ◽

Vol 10 (Especial) ◽

pp. 65-70

Author(s):

Adriano Seidi Demarchi Mikami ◽

Larissa Queiroz Minillo

Keyword(s):

Mechanical Properties ◽

Statistical Analysis ◽

Axial Compression ◽

Castor Oil ◽

Physical And Mechanical Properties ◽

Structural Timber ◽

Assembly Process ◽

Fast Growing ◽

Polyurethane Resin ◽

Glued Laminated Timber

The interest in replacing native wood with fast growing reforestation wood is recurrent, aiming at larger quantities of material in less time with no losses in its resistive properties. This paper consists in comparing the behavior of in natura structural timber parts with glued laminated timber, made with polyurethane resin based on castor oil, with regard to the resistance to axial compression. The assembly process of these pieces aims to achieve a similar or even superior resistance to the solid ones, considering that the MLC method allows the construction of structural pieces of many sizes and formats using different pieces of wood. Two this end, two species of wood, Pinus and Eucalyptus will be compared. The polyurethane resin, manufactured by the company Imperveg, was used in the process of glueing the stacks together. Evaluations will be performed according to NBR7190 (1997) aiming to characterize the physical and mechanical properties of the pieces and the results obtained will be submitted to statistical analysis by the Anova method.

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Timber structures. Structural timber and glued laminated timber. Determination of shear strength and mechanical properties perpendicular to the grain

10.3403/01306616 ◽

1998 ◽

Cited By ~ 1

Keyword(s):

Mechanical Properties ◽

Shear Strength ◽

Structural Timber ◽

Timber Structures ◽

Glued Laminated Timber

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Elements of the Fourth Industrial Revolution in the Production of Wood Buildings

Tehnički glasnik ◽

10.31803/tg-20200618130201 ◽

2020 ◽

Vol 14 (3) ◽

pp. 365-368

Author(s):

Jozef Švajlenka ◽

Mária Kozlovská

Keyword(s):

Industrial Revolution ◽

Solid Wood ◽

Academic Community ◽

Wood Products ◽

Sustainable Construction ◽

Industrial Building ◽

Construction Technology ◽

Glued Laminated Timber ◽

Efficient Construction ◽

Timber Products

We are on the threshold of a technological revolution that fundamentally changes the way we live, work and communicate with each other. To some extent, scale and complexity, this transformation will be as fundamental to humanity as no other technological change in the past. We do not know how it will evolve, but one thing is clear: the response to it must be integrated and comprehensive, involving all stakeholders on a global basis, from the public to the private sector, to the academic community and to civil society. In the context of sustainable and efficient construction, traditional material bases such as wood are becoming increasingly prevalent and implemented in modern design processes and design solutions. The great potential of this building material is achieved due to developments in production as well as the actual construction of timber buildings. Possible ways of production and construction of wooden buildings are diverse. Especially through prefabricated and solid wood products, which are also cross-glued laminated timber products, modern timber construction represents an interesting and sustainable construction technology. The aim of this paper is to define the basic aspects of industrial building industry in the context of new trends and to introduce the possibilities of implementation of elements of industry 4.0 in the field of wood-based construction.

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