Avaliação da resistência de juntas coladas com diferentes adesivos e análise estrutural de colunas em madeira lamelada colada com reforços em aço

Abstract

The growing demand for sustainable construction has promoted the use of renewable materials, with reforestation wood emerging as a viable alternative for this industry. One of the possible applications of wood is in prefabricated structures, such as glued laminated timber (Glulam). Additionally, composite wood-steel structures have gained recognition in various structural applications due to the combined benefits of both materials. Within this context, this study comprises three distinct investigations: two focused on adhesive technologies applied to Glulam structures and one on the fabrication and testing of composite wood-steel structures. The first investigation analyzed the shear strength under compression and torsion of Pinus sp. joints bonded with single-component polyurethane adhesive (1C-PUR) at different fiber orientations. Hankinson’s formula was also evaluated as a predictor of joint strength and wood failure percentage. The second study examined the mechanical performance of Pinus sp. joints bonded with Araldite epoxy adhesive under varying bonding pressures and adhesive grammages. Lastly, the third study assessed the structural behavior— under bending and compression—of Glulam columns made from Pinus sp., bonded with epoxy-based resin adhesive, and reinforced with lateral steel plates, comparing their performance to unreinforced columns. Across all studies, the wood was classified into density-based blocks. Results from the first study indicated that shear strength was affected by the bonding angle in the compression test. Additionally, while Hankinson’s formula proved useful in estimating shear strength under compression for bonded joints at different angles, it was not suitable for predicting shear strength under torsion. In the second study, it was found that, for epoxy adhesive, higher bonding pressure led to reduced joint strength, whereas adhesive grammage had no significant impact. The third study revealed that steel-reinforced columns outperformed unreinforced ones in terms of mechanical performance. The composite Glulam-steel structures demonstrated 5.1 times greater stiffness in bending compared to conventional Glulam structures. However, in compression, steel reinforcement did not significantly enhance stiffness except in low-density specimens. On average, steelreinforced columns withstood 93% higher loads than their unreinforced counterparts.