Comparison Between Test Methods to Determine Wood Embedment Strength Parallel to the Grain

Abstract

-This study compares the test methods according to the ABNT NBR 7190:1997, EN 383:2007, ASTM D5764:2007, EUROCODE 5:20042001 standards in order to provide support to establish a new test method for determining the embedment strength of wood parallel to the grain. Parallel-to-grain tests were carried out for six wood species (Schizolobium amazonicum; Pinus elliottii; Pinus oocarpa; Hymenaea spp.; Lyptus®: hybrid Eucalyptus grandis and Eucalyptus urophylla, and Goupia glabra) using four diameters (8 mm, 10 mm, 12 mm and 16 mm) for the metal pin fasteners (bolts). The experimental results obtained according to the EN 383:2007 standard were closer to the specific values for the metal-dowel connections design used by ABNT NBR 7190:1997, which are considered equal compression parallel to the grain. The use of maximum embedment force or the force causing displacement of 5 mm between the bolt and the testpiece as criteria for determining embedment strength for EN 383:2007 appears to be more appropriate than the criteria used by the Brazilian and American Standards.

Physical and mechanical properties of Eucalyptus saligna wood for timber structures

“…The strength properties of Eucalyptus saligna indicated increases with the moisture content decrease (30 to 12%) such as 19.44% (9.1 MPa) compression parallel to grain, 0.2% (4.17 MPa) compression perpendicular to grain, 21.99% (21 MPa) tension parallel to grain, 24.39% (1 MPa) tension perpendicular to grain and 19.10% (17.5 MPa) in modulus of rupture in static bending. Thus, the t-test analysis showed ft0, ft90 and fc0 suffered influence in their mean values when these properties were submitted to the moisture decrease (P-value ≤ 0.05), similar to the results obtained by Almeida et al (2016). This situation was not similar in fc90, because it did not present significant difference in their mean values with the decrease of moisture content (Table 3).…”

“…Lima et al (2014) reported basic density, compression parallel to the grain and shear parallel to the grain of Eucalyptus resinifera wood, equal to 0.74 g/cm³, 55.87 and 16.16 MPa, respectively, all of which are higher than those determined for Eucalyptus saligna wood. 14.00 12.00 Almeida and Dias (2016) determined the apparent density and the compression parallel to grain of Lyptus ® wood species (Eucalyptus hybrid) equal to 0.55 g/cm³ and 53.6 MPa, respectively. Even though the density was low when compared to Eucalyptus saligna, Lyptus presented a fc0 mean value higher than the batch of Eucalyptus saligna.…”

“…Another important characteristic of wood for timber structures is its moisture content (KOLMANN;CÔTÈ, 1968;HERZOG et al, 2000). In general, wood with higher moisture content presents lower mechanical properties (MATOS;MOLINA, 2016;ALMEIDA et al, 2016) and dimensional stability that is also influenced by moisture content (ALMEIDA et al, 2017).…”

Resistência da madeira ao embutimento perpendicular às fibras: comparação de métodos de ensaio

“…A resistência da madeira ao embutimento é a propriedade mecânica relacionada com o estado múltiplo de tensões na interface madeira e pino metálico (ALMEIDA, 2014;ALMEIDA et al, 2014bALMEIDA et al, , 2014c. O estudo dessa propriedade pode ser realizado nas direções paralela e perpendicular em relação às fibras, de acordo com procedimentos experimentais recomendados por normas (SANDHAAS et al, 2013;KENNEDY et al, 2014;SANTOS;JESUS;MORAIS, 2015;DIAS, 2016;MOLINA et al, 2017).…”

Propriedades físicas e mecânicas da madeira Tatajuba (Bagassa guianensis) proveniente de duas diferentes regiões brasileiras

“…Em relação à flora, a região é abundante, sendo que estudos recentes estimam que exista 16 mil espécies diferentes de árvores (no território Brasileiro, a projeção é que haja 12655) [1,2]. Para a utilização racional da madeira na construção civil (como elemento estrutural ou como parte da edificaçãopisos, forros e guarnições) é requisito básico o conhecimento de suas propriedades físicas e mecânicas [3][4][5].…”