Muh. Yusram Massijaya

Physical-Mechanical Properties of Glued Laminated Timber Made from Tropical Small-Diameter Logs Grown in Indonesia

ABSTRACT The aim of this study was to determine the physical and mechanical properties of glued laminated timber (glulam) manufactured from small-diameter logs of three wood species, Acacia mangium (mangium), Maesopsis eminii (manii), and Falcataria moluccana (sengon), with densities of 533, 392, and 271 kg/m 3 , respectively. Glulam measuring 5 cm by 7 cm by 160 cm in thickness, width, and length, respectively, was made with three to five lamina, or layers, and isocyanate adhesive. The glulams contained either the same wood species for all layers or a combination of mangium face and back layers with a core layer of manii or sengon. Solid wood samples of the same size for all three species were included as a basis for comparison. Physical-mechanical properties and delamination tests of glulam referred to JAS 234:2003. The results showed that the properties of same species glulam did not differ from those of solid wood, with the exception of the shear strength of glu-lam being lower than that of solid wood. Wood species affected glulam properties, but three- and five-layer glulams were not different except for the modulus of elasticity. All glulams were resistant to delamination by immersion in both cold and boiling water. The glulams that successfully met the JAS standard were three- and five-layer mangium, five-layer manii, and five-layer mangium-manii glulams.Keywords : Glulam, solid wood, small-diameter logs, physical and mechanical roperties, delamination

Resistance of Smoked Glued Laminated Lumber to Subterranean Termite Attack

Abstract Timber from plantation forest mostly contains sapwood, and the heartwood part has a lot of juvenile wood, which has low resistance to attack by subterranean termites (Coptotermes curvignathus). Wood smoke created through pyrolysis contains numerous polycyclic aromatic hydrocarbons that could prevent termite attack. Three-layer glued laminated lumber (glulam) was created using either the same wood species (mangium [Acacia mangium], manii [Maesopsis eminii], or sengon [Falcataria moluccana]) for all layers or a combination of mangium as the face and back layers and a core layer of manii or sengon. Glulam samples were exposed to smoke from mangium wood for 15 days, preserved with imidacloprid, or left untreated. All glulams were tested against subterranean termites according to the Indonesian standard. Gas chromatography revealed that smoke from mangium predominantly contained acetic acid, cyclobutanol, and phenolic compounds. Smoked glulam was more resistant to subterranean termite attack than untr...

Feeding rate of termites in wood treated with borax, acetylation, polystyrene, and smoke

Mindi (Melia azedarach) wood with density of 0.43 g/cm3 from Indonesia and sugi (Cryptomeria japonica) wood with density of 0.34 g/cm3 from Japan were treated with borax preservative, acetylation, polystyrene, and smoke. Treated and untreated wood samples were tested for resistance against subterranean termite (Coptotermes curvignathus) and dry wood termite (Cryptotermes cynocephalus) in the laboratory according to Indonesian standards. In addition to determining resistance of treated woods to termite attack, this work also evaluated termite feeding rates. The results showed that mindi has better resistance to subterranean and dry wood termite attack than sugi. All treatments effectively increased resistance to subterranean and dry wood termite attacks as shown by treated wood samples having less weight loss, higher resistance class, higher termite mortality, and a lower termite feeding rate compared to untreated wood. Daily termite feeding rate of untreated mindi was 50.3 μg/termite and sugi 95.8 μg/termite, the feeding rate of sugi was higher than mindi probably because sugi has a lower density and contains early wood, which both make termite feeding activity easier. The wood treatments effectively decreased the daily feeding rate of the termites.

A New Method To Estimate Modulus Of Elasticity And Modulus Of Rupture Of Glulam I‐Joist

Glulam consists of laminaes and each laminae influences glulam’s strength. Transformed cross section (TCS) method is a well known method to calculate the modulus of elasticity (E) and modulus of rupture (SR) of glulam. However, the TCS does not follow the principles due to its assumption that the material properties depend on its shape and size. Therefore, a new calculation method is required. This paper discusses the formulation of a new method to determine E and SR of glulam. It was found that E and SR calculated by the TCS and new methods are the same. The new method confirms the independencies of E and SR which could not be fulfilled by the TCS one. Therefore, the TCS method could be replaced by the new method.

Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species

The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana), mangium (Acacia mangium), and pine (Pinus merkusii) were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance) to 10 (complete or near-complete resistance). Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples.

Utilization of Coir and Recycled Polypropylene for Bamboo Matting Layer Composite

Utilization of non wood material as raw material in wood industry would be increase in the future because environmentally issues. The objective of this research were to evaluate characteristic of coir, recycled polypropylene (RPP), and tali bamboo (Gigantochloa apus) as raw material in composite board and find out the optimum quality of composite board made from its material. The board samples target density was 0.7 g/cm3. The board construction type was core type composite board (three layers). The bamboo sheet wide was 1 cm and 2 cm with and without bark. The bamboo matting was used in angle and perpendicular orientation to length of the board. The results showed that coir, RPP, and tali bamboo suitable for composite board material. Utilization of bamboo matting layers increases the mechanical properties of board, except internal bond. All of composite board made from coir and RPP with bamboo matting layers fulfill the JIS A 5908 standard in density and thickness swelling after 2 and 24 hours of water immersions. However, only composites with bamboo matting layers with bark and sheet wide 1 cm fulfill JIS A 5908 standard for veneered particleboard in MOE.