Physical-mechanical characterization of the glue laminated bamboo ( Dendrocalamus giganteus )

Abstract

Esta pesquisa teve como objetivo avaliar a influ\ueancia do tratamento preservativo e do tipo de adesivo nas propriedades f\uedsico-mec\ue2nicas do laminado colado, confeccionado com o bambu Dendrocalamus giganteus . Para tanto, colmos de bambu foram tratados pelo m\ue9todo de imers\ue3o em produto qu\uedmico (solu\ue7\ue3o de 1% de ingredientes ativos de borato de cobre cromatado \u2013 CCB) e em \ue1gua, durante 15 dias. Dos colmos tratados, foram retiradas as camadas externa e interna, obtendo-se l\ue2minas com espessuras de 4 mm, comprimento de 45 cm e largura de 5 cm. Para a colagem das l\ue2minas, utilizaram-se os adesivos "Cascophen RS" (resorcinol-formol) e "Cascorez-Extra" (acetato polivin\uedlico). O adesivo \ue0 base de resorcinol-formol proporcionou maior resist\ueancia \ue0 umidade ao BLC, quando comparado \ue0quele \ue0 base de acetato polivin\uedlico, tendo as amostras provenientes de pe\ue7as tratadas com CCB sido mais est\ue1veis que as tratadas com \ue1gua. Dentre as propriedades mec\ue2nicas testadas, o adesivo apresentou resultado significativo para o cisalhamento na linha de cola e o tratamento preservativo para o MOE. A intera\ue7\ue3o dos fatores adesivo e tratamento foi significativa para o MOE, resist\ueancia a compress\ue3o paralela ao cisalhamento na linha de cola, tendo as pe\ue7as tratadas com \ue1gua e aderidas com resorcinol-formol apresentado melhores resultados para o MOE e compress\ue3o paralela \ue0s fibras e aquelas tratadas com CCB, para o cisalhamento na linha de cola.The purpose of this work was to evaluate the preservative treatment effect and the adhesive type in physical-mechanical properties of glue laminated bamboo (GLB) of Dendrocalamus giganteus . Thus, the bamboo stems were treated by immersion method with chemical product (solution of 1% of active ingredients of copper chrome borate - CCB) and water by 15 days. Before treating the stems, the external and internal parts were removed to obtain the flat strips of bamboo with 4 mm of thickness, 45 cm of length and 5 cm of width. The "Cascophen RS" (resorcinol-formaldehyde) and "Cascorez-extra" (polyvinyl acetate) commercial adhesives were used to bond the flat strips. The resorcinol-formaldehyde adhesive showed superior moisture resistance than polyvinyl resin to GLB, and the samples obtained of pieces treated with CCB were more stable than treated with water. Among the mechanical properties tested, the adhesive factor was significant for the resistance to shear parallel to glue line and the preservative treatment for the rigidity. The interaction of the factors adhesive and treatment was significant for the rigidity, resistance to parallel compression and shear parallel to glue line. The pieces treated with water and adhered with resorcinolformaldehyde presented better results for the rigidity and parallel compression to the fibers and those treated with CCB, for the shear parallel to glue line