Percentual de falha na madeira colada com adesivo epóxi

Abstract

The adhesive’s main function is to ensure adhesion between materials, in addition to providing fluidity and filling gaps in the joints. Information such as grammage and bonding pressure are essential in the execution of laminated wood structures. The objective of this study was to evaluate the failure percentage in Pinus sp. wood joints bonded with epoxy adhesive. The materials used were Pinus sp. wood and the twocomponent epoxy adhesive, commercially known as Araldite Professional. The wood joints were made following the guidelines of ASTM D 905 (2013) and NBR 7190 (ABNT, 2022) standards. Four pressure levels were tested: 0.6 MPa, 0.8 MPa, 1.0 MPa, and 1.2 MPa, and six grammage levels: 80 g/m², 150 g/m², 200 g/m², 250 g/m², 300 g/m², and 350 g/m². The apparent density was determined, and the lot was subdivided into six blocks. Additionally, the failure percentage in the test specimens was assessed after shear testing. The average failure percentage in the wood was 77.90%, meeting the criteria established by the ASTM D 5266 (2005) standard. Furthermore, among the 24 treatments studied, only five do not meet the requirements of this standard, showing average failure percentages in the wood below 75%. The use of 80 g/m² grammage is not recommended, regardless of the applied pressure, as well as the use of grammages above 250 g/m² with pressures exceeding 1.0 MPa.