Properties of Rubberwood LVL reinforced with Acacia
Author(s)WONG, Ee Ding; RAZALI, Abdul-Kader; KAWAI, Shuichi
Wood research : bulletin of the Wood Research Institute Kyoto
University (1996), 83: 8-16
Type Departmental Bulletin Paper
KURENAI : Kyoto University Research Information Repository
Properties of Rubberwood LVL reinforced
with Acacia Veneers*l
WONG Ee Ding*2, RAZALI Abdul-Kader*3
and Shuichi KAWAI*2
(Received May 31, 1996)
Abstract--The properties oflaminated 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) ofthe LVL, with Rubberwood veneers in the core.
two Rubberwood: Mangium combination ratios were studied, i.e., 3: 2 and 1: 2.
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 ofMangium, respectively.
not seem to improve the m o d u l u ~ 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 l20E Special Grade.
The effects of
Reinforcement using 3 Mangium plies did
Key words: Laminated veneer lumber, reinforced, Hevea brasiliensis, Acacia mangium, melamine urea
The previous study has shown the technical feasibility to produce structural grade
laminated veneer lumber (LVL) from Rubberwood (Hevea brasiliensis) and Mangium (Acacia
mangium) using phenol formaldehyde (PF), melamine urea formaldehyde (MUF) and urea
formaldehyde (UF) as the binders!).Except where UF was used as the binder, Mangium
LVL generally had higher shear strength compared to Rubberwood LVL.
bending, Mangium LVL registered higher modulus of elastic (MOE) and modulus of
rupture (MaR) than Rubberwood LVL, irrespective ofresin type.
In term ofstatic
The uniformity ofboth
*1 This paper was presented at IUFRO XX World Congress, 6-12 August 1995, Tampere, Finland.
*2 Laboratory of Structural Function.
*3 Golden Hope Fibreboard, P.O. Box 10, 71807 Nilai, Malaysia.
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and H. Yukun eds.;China Forestry Publishing House, Beijing, 1994, P.72.,...82
2) T.L.LAUFENBERG: Proceedings on Structural Wood Composites, Meeting Today's Needs and
Tomorrow's Challenges, 12-14 November, 1984.
Research Society, 1985, P.41-53.
Minneapolis, MN. Madison, WI., Forest Products