STRUCTURAL EFFICIENCY AND FLEXURE STRENGTH OF MIX-GLULAM TIMBER BEAMS ARE COMPOSED OF SENGON AND COCONUT WOOD AS GREEN MATERIAL CONSTRUCTIONS

Abstract

Wood is a green materials that has a low level of embodied energy. Production of sawn timber is very efficient because it can reduce; reuse and recycling. Two species of wood that could be developed is sengon and coconut wood. The problem is that sengon wood have not an adequate mechanical performance. On the other hand, coconut wood has a good mechanical properties, but the heavy weight becoming an obstacle. Therefore, it is necessary to increase the performance of them. The improvement is achieved by a mix-glulam system that will be produced a lightweight structural timber beams. This research was conducted through a three and four point bending test according to ASTM:D 198 – 02. The coconut wood was placed as the outer zone of glulam. The beams size is 55mm in width, 155 mm in depth and 1740 mm in span. As a control parameter used the mechanic behavior of clear specimen as initial strength. The experimental results showed that the mix-glulam system can increase the flexure strength and stiffness by 6.1% and 8.4% respectively. In addition, the lamination process could be to improve the flexure strength and modulus of elasticity sengon-wood by 8.4% and 26% respectively. On the other hand the lamination process causes a decrease in ductility of 14%, so the glulam beams failure that occurred tend to be more brittle. In terms of structural efficiency, mix glulam has a level much better than concrete and almost equivalent to steel.