scholarly journals Shear Strength of Joints in Glued Laminated Timber: Normative Verification of Bibliography Results

2018 ◽  
Vol 8 (6) ◽  
pp. 152-157
Author(s):  
Eduardo Chahud ◽  
Roberto Vasconcelos Pinheiro ◽  
Vinicius Borges de Moura Aquino ◽  
Thiago Damasceno Silva ◽  
Julia Naves Teixeira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Glued Laminated Timber

Shear strength of spruce glued—laminated timber beams

1985 ◽  
Vol 12 (3) ◽  
pp. 661-672 ◽  
Author(s):  
F. J. Keenan ◽  
J. Kryla ◽  
B. Kyokong
Keyword(s):  
Shear Strength ◽  
Cross Sections ◽  
Weibull Model ◽  
Longitudinal Shear ◽  
Douglas Fir ◽  
Published Data ◽  
Cross Sectional ◽  
Characteristic Value ◽  
Glued Laminated Timber ◽  
Timber Beams

The effect of size on longitudinal shear strength has been well established for Douglas-fir glued–laminated (glulam) timber beams. The present study examined whether this phenomenon exists in glulam beams made of spruce. The experiment consisted of three projects in which beams of various sizes were tested under concentrated mid-span load. The project A beams had clear spruce webs and white elm flanges with cross-sectional dimensions varying from 25 × 25 mm to 75 × 75 mm. The project B beams had spruce glulam webs with Douglas-fir flanges; cross sections ranged from 20 × 100 mm to 90 × 200 mm. In project C, three groups of 10 replications of commercially representative sizes of glulam beams were made from stiffness-rated spruce–pine–fir lumber. The beam cross sections were 76 × 200 mm, 76 × 400 mm, and 127 × 400 mm.The results indicated that depth, width, and shear plane had significant effects on the longitudinal shear strength of the beams in project A. Depth, width, and shear span of the small glulam beams in project B also had highly significant effects on shear strength. However, no effects of depth and width on the shear strength of glulam beams in project C were found. Regression analysis showed no dependence of shear strength on sheared volume for the beams of all three projects. The three-parameter Weibull model also failed to predict the near-minimum shear strength of spruce glulam beams. The results suggested that the lower-bound shear strength of spruce glulam beams is a constant (regardless of beam volume) and could be used as a single characteristic value for glulam design in shear. Further review of published data indicates that this may also be the case for Douglas-fir glulam but with a lower characteristic value than for spruce.

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

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.

scholarly journals EFEITO DA GRAMATURA SOBRE A RESISTÊNCIA AO CISALHAMENTO DA LINHA DE COLA DE DUAS MADEIRAS TROPICAIS: SERU (Allantoma lineata) E MARUPÁ (Simarouba amara)

FLORESTA ◽  
2010 ◽  
Vol 40 (2) ◽  
Author(s):  
Cristiane Moreira Tavares dos Santos ◽  
Cláudio Henrique Soares Del Menezzi
Keyword(s):  
Shear Strength ◽  
Quadratic Model ◽  
Spread Rate ◽  
Design Code ◽  
Shear Tests ◽  
Direct Tension ◽  
Glued Laminated Timber ◽  
Wood Bonding ◽  
The Press ◽  
Tropical Woods

Este trabalho teve como objetivo principal estudar a influência da gramatura do adesivo resorcinol-formaldeído na união de peças de madeira, visando à produção de madeira laminada colada (MLC) de duas espécies, seru (Allantoma lineata) e marupá (Simarouba amara), e da mistura entre elas. Foram realizados testes de cisalhamento na linha de cola conforme a NBR 7190 (1997), bem como foi calculada a percentagem de falha na madeira para as duas espécies e para dois tipos de mistura entre elas nas gramaturas 200, 300 e 400 g.m-², além de testes de cisalhamento longitudinal das madeiras sólidas. As espécies e misturas se correlacionam com a gramatura através de um modelo quadrático, no qual a maior resistência foi obtida próximo à gramatura de 300 g.m-2, não sendo significativo ao nível de 5% de probabilidade apenas para a mistura na qual a madeira de seru recebeu o esforço direto da prensa. Os resultados mostraram que a ligação adesivo-madeira foi mais eficiente para a espécie marupá, de baixa densidade. Entretanto, a maior média de resistência ao cisalhamento (9,46 MPa) foi obtida para a colagem da espécie seru. Para ambas as espécies, as gramaturas 300 e 400 g.m-2 atingiram o requisito da NBR 7190, que estabelece que a eficiência do adesivo deve ser superior a 90%. Os resultados indicaram a possibilidade de mistura de ambas as espécies. Palavras-chave: Madeira laminada colada; gramatura; Allantoma lineata; Simarouba amara.   Abstract Effect of the spread rate on glue shear strength of two tropical hardwoods: seru (Allantoma lineata) and marupá (Simarouba amara). This study aimed at studying the effect of the glue spread rate on bonding strength of two tropical woods: Seru (Allantoma lineata) and Marupá (Simarouba amara). All the shear tests were acomplished according to the Brazilian Design Code NBR 7190 (ABNT, 1997), for each specie and on two kinds of mixtures of these species. For both species they were also done tests to verify the parallel shear strength in solid woods. Using these tests, they were determined the shear strength and the percentage of wood failure for each specie and for their mixtures, using the followings amounts of glue: 200, 300 and 400 g.m-2. Afterwards, the best statistic obtained model, relating the amounts of glue to the woods cited above, was the quadratic model. The best shear strength was obtained around 300 g.m-2 and was considered not significant at the level of 5% of probability only for a unique kind of mixture, where Seru receives direct tension of the press machine. The highest shear strength average, 9,46 MPa, was obtained for the Seru wood bonding junction. For both species the amounts of glue 300 and 400 g.m-2 met the NBR 7190 requirement, which states that the efficiency of the adhesive strength must be above 90% in comparison to the solid wood.Keywords: Glued-laminated timber; glue amount; Allantoma lineate; Simarouba amara.

scholarly journals Shear Block Test Performance of Melunak and Mengkulang

2018 ◽  
Vol 7 (3.11) ◽  
pp. 210 ◽  
Author(s):  
Nor Jihan Abd Malek ◽  
Rohana Hassan ◽  
Azmi Ibrahim ◽  
Mohammed Hasan Alhebshi
Keyword(s):  
Shear Strength ◽  
Wood Surface ◽  
Test Performance ◽  
Bonding Performance ◽  
Average Shear Strength ◽  
Glued Laminated Timber ◽  
Strength Tests ◽  
Average Shear ◽  
Block Test ◽  
Shear Block

This paper presented results of shear block test performance of tropical glued-laminated timber (glulam) from species of melunak and mengkulang. Glulam blocks were manufactured in accordance with MS758:2001. The shear block test for glue lines and the shear strength tests of melunak and mengkulang were conducted and evaluated in accordance with BS EN 14080:2013. Melunak and mengkulang produced average shear strength values of 10.62 N/mm2 and 8.19 N/mm2, respectively. In terms of wood and glue failure percentage, the results showed that melunak and mengkulang were mainly failed due to wood surface area and not due to the glue lamination in which both melunak and mengkulang showed a good bonding performance. 

ASSESSMENT IN BENDING AND SHEAR STRENGTH OF GLUED LAMINATED TIMBER USING SELECTED MALAYSIAN TROPICAL HARDWOOD AS ALTERNATIVE TO TIMBER RAILWAY SLEEPERS

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Norshariza Mohamad Bhkari ◽  
Zakiah Ahmad ◽  
Afidah Abu Bakar ◽  
Paridah Md. Tahir
Keyword(s):  
Shear Strength ◽  
Shear Test ◽  
Bending Strength ◽  
Bending Test ◽  
Structural Members ◽  
Tropical Timber ◽  
Bond Performance ◽  
Tropical Hardwood ◽  
Glued Laminated Timber ◽  
Bonding Characteristics

This paper presents a pilot study on bending and shear strength of glued laminated (glulam) timber using selected tropical timber namely, Kekatong (Cynometra spp.) and Melagangai (Potoxylon melagangai) as an alternative for timber railway sleepers. Selected timbers were manufactured in accordance with MS758:2001 and the bending test was conducted according to ASTM D198:2013. The shear test for glue line integrity was performed to observe the bond performance in glulam accordance to MS758:2001.The results showed both species can be used as structural members since the bending strength obtained from the laboratory work is greater than the allowable bending strength. In terms of the percentage of wood failure, the bonding characteristics of both glulam satisfied the bonding requirement stipulated in the standard and have the potential to be used as glulam timber railway sleepers.  

Deflection behavior and load-bearing period of structural glued laminated timber beams in fire including cooling phase

2018 ◽  
Vol 9 (4) ◽  
pp. 287-299
Author(s):  
Hitoshi Kinjo ◽  
Yusuke Katakura ◽  
Takeo Hirashima ◽  
Shuitsu Yusa ◽  
Kiyoshi Saito
Keyword(s):  
Shear Strength ◽  
Bearing Capacity ◽  
Shear Failure ◽  
Fire Performance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Content Type ◽  
Glued Laminated Timber ◽  
Cooling Phase ◽  
Timber Beams

Purpose This paper aims to discuss the fire performance of glulam timber beams based on their deflection behavior and load-bearing period, which were obtained from load-bearing fire tests under constant load conditions. Design/methodology/approach In this report, the fire performance, primarily deflection behavior and load-bearing period of glued laminated (glulam) timber beams will be discussed from the standpoint of load-bearing fire tests conducted during the cooling phase under constant load conditions. Then, based on the charring depth and the per section temperature transformation obtained from loading test results, the load-bearing capacity of the glulam timber beams will be discussed using the effective section method and the strength reduction factor, which will be calculated in accordance with the European standards for the design of timber structures (Eurocode 5). Findings In the cooling phase, the charring rate is decreases. However, as the temperature in the cross section rises, the deflection is increases. The failure mode was bending failure because of tensile failure of the lamina at the bottom of the beam. Moreover, a gap caused by shear failure in a growth ring in the beam cross-section in the vicinity of the centroid axis was observed. Shear failure was observed up until 1 to 3 h before end of heating. The calculated shear strength far exceeded the test results. Shear strength for elevated temperature of glued laminated timber is likely to decrease than the shear strength in Eurocode 5. Originality/value Unlike other elements, a characteristic problem of timber elements is that their load-bearing capacity decreases as they are consumed in a fire, and their bearing capacities may continue to degrade even after the fuel in the room has been exhausted. Therefore, the structural fire performance of timber elements should be clarified during not only the heating phase but also the subsequent cooling phase. However, there are few reports on the load-bearing capacity of timber elements that take the cooling phase after a fire into consideration.

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