Construção e ensaio de pórticos em madeira colada com reforço nas ligações

Abstract

Building materials from sustainable sources have being increasingly used in construction sites in order to avoid the processes of global warming. Using wood for structural purposes has presented itself as environmentally advantageous solution, especially if it comes from planted forests. One of the most used structural systems in Brazil for building sheds are portics. They are structures composed of pillars and beams working together as one, which are generally used in rural, commercial and industrial construction. Although effective, experimental analyzes of glued laminated timber portics behavior – glulam portics are still rare. In addition, recent researches with glulam frame structures rise the possibility of optimizing these systems using reinforcements at specific key points of the structure. After an initial test, conducted with the reassembled structure from Stringari (2019), a 42% increase in strength was obtained when including lateral reinforcements in the main connections of the researcher's structures. Therefore, the purpose of the present work is to build and test five framed structures of glued laminated timber, built using Araucaria angustifolia wood and polyurethane adhesive based on vegetable oils. The frames maintained the geometry of Stringari's (2019) work, but with reinforcements on the connections between the roof beams and the pillars. The rupture force values of the structures were, on average, 38.02 kN, approximately 5.47 times the design load and showed an increase of 32% of resistance when compared to the non-reinforced structures of Stringari (2019). The measured displacements, especially on the ridge, did not reach the brazilian normative limit for the design load and presented a linear behavior for forces greater than three times the designed ones. The structures presented a satisfactory structural behavior and the use of glulam and adhesive based on vegetable oils can be considered viable for the execution of portics.