Performance of Glued Laminated Timber (Glulam) Made from Kelempayan Wood with Different Lamina Assembly Patterns and Adhesive Spread Rates

Abstract

This study investigates the impact of adhesive spread rates and lamina assembly patterns on the physical and mechanical properties of glue laminated lumber (glulam) manufactured from Kelempayan wood (Neolamarckia cadamba (Roxb.) Bosser). For this purpose, lab-scale 3-ply homogenous glulams were manufactured using low-MOE, average-MOE, and high-MOE laminas, and 3-ply mixed glulams of low-high-low-MOE and high-low-high-MOE lamina, with an adhesive spread rate of 100 g/m2 applied on both sides of the lamina. A 3-ply homogenous glulam was also manufactured using the average-MOE lamina with an adhesive spread rate of 200 g/m2. The physical and mechanical properties of the glulam, including moisture content, density, modulus of rupture (MOR), and modulus of elasticity (MOE), were examined and compared to the Japanese Industrial Standards (JAS) for glulam. The results found that the adhesive spread rates did not have a significant effect on the physical and mechanical properties of the glulam. However, the lamina assembly patterns had a significant impact on the mechanical properties of the glulam. The highest MOR and MOE were observed in the homogenous glulam manufactured from the high-MOE laminas, followed by the mixed glulam manufactured from the high-low-high-MOE laminas. These assembly patterns meet the MOR and MOE requirements specified in the 3-ply homogeneous structural grade glulam standard, indicating that Kelempayan wood can be a feasible option for glulam production.