Properties of Rubberwood LVL reinforced with Acacia Veneers

Source: OAI


この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。 The properties of laminated veneer lumber (LVL) [15-ply, 3.6 mm veneer thickness] produced from Acacia mangium (Mangium) thinnings, Hevea brasiliensis (Rubberwood) and their combinations were investigated. Melamine urea formaldehyde (MUF) was used as the binder. In the species combination, Mangium veneers were incorporated in the tension and compression zones (i.e., top and bottom layers) of the LVL, with Rubberwood veneers in the core. The effects of two Rubberwood: Mangium combination ratios were studied, i.e., 3 : 2 and 1 : 2. Rubberwood LVL reinforced with Mangium exhibited a lower degree of bow compared to pure Rubberwood LVL. The LVLs were evaluated in accordance with the Japanese Agricultural Standard for Structural LVL (1993). All of the LVLs passed the cold water soak and boiling water delamination tests. Similar dry shear strength was registered by all of the LVLs, with shear retention of 58 to 63% after cyclic boiling. LVL with higher proportion of Mangium recorded higher shear strength retention. Modulus of elasticity (MOE) was found to increase with increasing Mangium plies in the faces. This is reflected by 2 and 12% MOE increment in LVL reinforced with 3 and 5 plies of Mangium, respectively. Reinforcement using 3 Mangium plies did not seem to improve the modulus of rupture (MOR), but 13% MOR increment was recorded by incorporating 5 plies of Mangium. Rubberwood and 3-ply Mangium reinforced LVL met the minimum requirements stipulated for 80E Special Grade, while the 5-ply Mangium reinforced LVL made the 100E Special Grade. Mangium LVL passed the 120E Special Grade.

Full-text preview

Available from:
  • Source
    • "Borri et al. [17] reinforced timber beams with hemp fiber, flax fiber, basalt fiber, and bamboo fibers, and determined that the beams had increased load-carrying capacity and deflection ductility. Wong et al. [18] reinforced rubber wood LVL with Acacia veneers in different combinations and stated that modulus of elasticity increased with increasing Acacia plies in the faces. In another study, Mohebby et al., [19] reinforced medium density fiberboard (MDF) with metal and woven synthetic nets, and they noted that there were significant increases in bending properties, especially with metal nets. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The reinforcement of solid wood and wood-based composite materials is not a new idea, but there have been very few studies about reinforcing poplar plywood with glass fiber fabric using phenol formaldehyde. In this study, plywood panels were produced using poplar veneer and phenol formaldehyde adhesive and glass fiber fabric. One control group and three different test groups were set up. In addition, perpendicular and parallel test samples for each group were set up for bending tests. Some of the physical and mechanical properties of the reinforced plywood were determined using various tests. The results of the testing indicated that the plywood that was reinforced with woven glass fiber had a significantly increased modulus of rapture and modulus of elasticity of perpendicular samples. It was determined that density of the plywood was increased in the test groups. Thickness swelling and water absorption decreased for the test groups in which the plywood samples had woven glass fibers bonded onto in their surfaces. In the bending tests, the reinforcement provided by the glass fiber fabric decreased the inequalities between the parallel and perpendicular samples.
    Full-text · Article · Dec 2015 · Construction and Building Materials
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cross-linked polyvinyl acetate (PVAc) adhesive and thin veneers of three low density wood species, namely silver maple, yellow poplar and aspen, were used to produce LVL engineered wood products using different press durations. Density, water absorption, thickness swelling, flexural strength and surface hardness were evaluated. Internal bond strength, tensile shear and block shear strengths were tested in dry, accelerated (boiling and dry) and cyclic (wet and dry) conditions. LVL made using cross-linked polyvinyl acetate and silver maple with a platen temperature of 38 °C for 5 minutes exhibited the best properties. LVL of silver maple veneers showed improved properties as compared to yellow poplar and aspen. Silver maple can be used suitably in laminated veneer flooring.
    No preview · Article · Mar 2008 · Holz als Roh- und Werkstoff
  • [Show abstract] [Hide abstract]
    ABSTRACT: Four different commercial resin formulations namely cross-linked polyvinyl acetate (XPVAc), melamine urea formaldehyde (MUF), urea formaldehyde (UF) and melamine formaldehyde (MF) were used to produce laminated veneer lumber (LVL) from yellow poplar veneers in the laboratory. Physical and mechanical properties were evaluated using ASTM (D 1037, D 906, D 5456) standards and compared. Internal bond, tensile shear and block shear strengths of specimens subjected to accelerated (boiled water) and cyclic (repeated cold water) conditions were also determined. Strength properties of yellow poplar LVL were improved compared with the solid wood. The properties of XPVAc bonded LVL were superior or comparable to the thermosetting adhesives. This study clearly indicated that cross-linked PVAc can be used to manufacture LVL with acceptable properties.
    No preview · Article · Nov 2009 · Holz als Roh- und Werkstoff
Show more