Engineering Properties of Solid and Laminated Glulam of Acacia mangium superbulk Planted in Sarawak

• Main Author: Nur Syahina, Yahya
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak 2024
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://ir.unimas.my/id/eprint/45132/1/PhD%20Thesis_Nur%20Syahina_18062024.pdf; http://ir.unimas.my/id/eprint/45132/

The slow growth rate of primer species has had an impact on the quantity available to meet market demand. To address this issue, a study was conducted to fully employ fast-growing timber as the principal resource in order to ensure that demand for timber logs remains stable. The purpose of this research was to study the engineering properties of Acacia mangium superbulk, a fast-growing timber species that planted in Daiken Plantation Bintulu, Sarawak with age groups of 7, 10 and 13 years old at air-dry moisture content. The small-clear samples were prepared in the form of solid and laminated (same age groups and different age groups) and set into untreated and treated for both solid and laminated sample products. The type of preservative and adhesive glue that have been used are Copper Chrome Arsenic (CCA) and Phenol-resorcinol Formaldehyde (PRF), respectively. The mechanical strength testing conducted are modulus of rupture (MOR), modulus of elasticity (MOE), compression parallel to grain and shear parallel to grain. This study also established the end-user applications in the timber industry based on density, hardwood category, strength grouping and hazard class. From the study, the maximum strength value of solid untreated is obtained by 10 years old, which is recorded the MOR, MOE, compression parallel to grain and shear parallel to grain are 115.11 N/mm2 , 14945 N/mm2 , 57.57 N/mm2 and 14.24 N/mm2 , respectively. Besides that, the maximum strength value of solid treated is also obtained by 10 years old, which is recorded 118.76 N/mm2 , 15020 N/mm2 , 57.82 N/mm2 and 13.67 N/mm2 for MOR, MOE, compression parallel to grain and shear parallel to grain, respectively. For laminated samples, there is no significant difference in strength from laminated untreated products 10 // 10 years old when compared to solid untreated 10 years old, and the percentage differences obtained by MOR, MOE, compression parallel to grain and shear parallel to grain are 2.45%, 0.31%, 3.58% and 3.37%, respectively. Meanwhile, the strength properties between laminated treated products 10 // 13 years old and solid treated 10 years old do not have any significant difference, and the percentage differences obtained by MOR, MOE, compression parallel to grain and shear parallel to grain are 3.37%, 0.06%, 3.91% and 1.17%, respectively. The treatment by CCA preservative shows the Acacia mangium superbulk is classified as moderately difficult to treat and hazard class of H4 (±14 litre/m3 ). The density of Acacia mangium superbulk at air- dry condition is 0.61 g/cm3 and its categorised as light hardwood. Moreover, at air-dry condition, the Acacia mangium superbulk is classified as Group A based on basic grade. Based on compression strength at air-dry condition, Acacia mangium superbulk is classified as Group A for laminated treated product by different age groups samples and Group B for solid untreated, solid treated, laminated untreated product by same age groups, laminated untreated product by different age groups and laminated treated product by different age groups samples. The end-user utilisations of Acacia mangium superbulk are recommended for structural components, roofing, staircase, flooring, walling, door, window, and decorative panelling.