DETERMINACIÓN DE LOS ESFUERZOS DE DISEÑO DE VIGAS LAMINADAS DE PINO CARIBE (Pinus caribaea var. hondurensis) ENCOLADAS CON ADHESIVO DE ISOCIANATO (MDI).

Static flexion tests of eighteen glued-laminated timber of caribean pine glued with isocyanate-based adhesives (MDI) were carried out following ASTM-D198-84 standards at the National Laboratory of Forest Products of "La Universidad de los Andes" (Mérida, Venezuela). These beams were fabricated, in their entirety, by the only company that develops glued-laminated (GLULAM) timber in Venezuela. The glued-laminated timber was divided into two groups of nine. The first group consisted of GLULAM timber made from whole beams of wood, while the second was composed of sectioned wood that had been finger-joined and later made into GLULAM beams. Each group was divided into three subgroups with glued-laminated timber of widths 65mm, 95mm and 125mm, but with a common height of 270mm and a length of 3500mm. The values obtained for stress at proportional limit, modulus of rupture and the modulus of elasticity for all the beams studied were less than those reported for glued-laminated timber from Chilean radiata pine and Argentinean resinous pine. Morphology studies performed on all the studied beams revealed that they presented great deficiencies in the physical quality of the wood, glue lines, and fabrication process. These factors are responsible for the low-performance of the test samples. It is recommended, in this first stage of the industry, that the mentioned technical aspects be improved so that resistance and structural quality of glued-laminated timber is in turn enhanced. [ABSTRACT FROM AUTHOR]