Avaliação de vigas de madeira laminada colada de cedrinho (Erisma uncinatum Warm.)

Abstract

Glued laminated timber (glulam) is assembled layers of bonded pieces of timber. In Brazil, the use of native species timber to produce structural elements of glulam does not occur in satisfactory technological conditions. This is because the properties and performance of native species of wood, under various service conditions, are not entirely known. This study aims at determining and to relate the dynamic modulus of elasticity (EMvt ) and the static modulus of elasticity (EM ), the modulus of rupture (fM ), the compression parallel strength (σcp ) and the parallel elastic modulus (Ecp ), and evaluating the performance of the native species Cedrinho (Erisma uncinatum Warm.) in the construction of glulam beams. Glulam beams were produced with random and nonrandom distributions of graded pieces of bonded lumber by using adhesives of phenol resorcinol formaldehyde (RFF) and polyurethane (PUR); the intensity of pressures used was 0.8 MPa and 1.2 MPa. The evaluation of these glulam beams was also performed using samples of compression parallel to glue lines and delamination. It was found that the EMvt obtained by transverse vibration dynamic testing revealed a correlation coefficient with the EM obtained on static bending test (R2 = 0.86) and significance level of 1% probability (P < 0,01). Thus, it can observed that the EMvt is a good estimator of EM. It was found that this wood species may be used for glulam, and that the hardwoods species is in strength class C30.