Pengujian Lentur Balok Laminasi-Mekanik Kayu Mahoni (Swietenia macrophylla King)

Abstract

Laminated beam (LB) is a modified product made of two or more laminas bonded with adhesive or mechanical joints. This research aims to determine the mechanical properties and analyze the flexural characteristics of mechanicallaminated beam (MLB). The MLB's manufacturing is divided into several sections: wood drying, LB manufacturing, arranging, bonding, clamping, conditioning, jointing using nails or screws, and testing. Three types of laminated beam was prepared in this research, with addition of one glued laminated timber (Glulam). Type-1 beam used screws or nails along its length as the jointer of laminas. Nails or screws on type-2 beam was put on the one third length of the span, on both ends of the beam, and given adhesive on the one third span, in the middle of the beam. Nail or screw on the type-3 was put on the one-third span, the middle, and adhesives on the one-third span on both ends of the beam. The results show that type-3 LB has highest modulus of elasticity (MOE) value. The highest value of MOE on LB with 0.3 cm-nails is 52298.58 kg/cm2; moreover, the lowest MOE was achieved by type-1 LB with 0.3 cm-diameter nails: 11077.41 kg/cm2. The highest modulus of rupture (MOR) value was achieved by type-1 LB with 0.3 cm diameter-nails, while the lowest was obtained on the type-3 LB with 0.5 cm diameter-nails: 207.36 kg/cm2. Glulam has higher MOE and MOR values compared to all MLB. The positioning of screws, nails, and adhesives on LB has significant effect on MOE value. The damage on MLB was shown in form of flexural failure and delamination.