The Characteristics of Glued-Laminated Beams Made from Small Diameter Fast-Growing Species

摘要

This paper presents the performance of glued-laminated (glulam) beams made from small diameter of two fast growing species, african wood (Maesopsis eminii Engl.) and mangium (Acacia mangium Willd.) using water based polymer isocyanate (WBPI) as a binder. Laminations were used consist of 2, 4, 6, 8 and 12 cm in widthnesses, 2 cm in thickness and 260 cm in length. Each lamination was graded using Machine Stress Grading (namely by Panter or plank sorter) to determine its modulus of elasticity (MOE). Cross-section of five types of glulam beams was 6 cm x 12 cm, arranged of various widths and based on MOE of laminations. The research results showed that glulam beams made from mangium showed better performance compared to those of african wood based on values of MOE and modulus of rupture (MOR). In general, results showed that almost all of glulam beams types of both wood species fulfill the JAS 234:2003 standard in moisture content, MOE, MOR, shear strength and immersion delamination test. However, performance of glulam beams was unsatisfactory in ratio wood failure and boiling water soak delamination test.