Original paper(Vol.47 No.4 pp.350)

Manufacturing condition and mechanical properties of cylindrical LVL manufactured by spiral-winding method

Yamauchi Hidefumi; Miura Izumi; Sasaki Takanobu; Koizumi Akio; Kawai Shuichi; Sasaki Hikaru

Abstract:The mechanical properties in bending and in compression of full size cylindrically laminated veneer lumbers (C-LVL) made by spiral winding method were tested. The C-LVLs have about 300 mm outer diameter, 25 mm wall thickness, and 3600 mm length. The results obtained are as follows: 1) The modulus of elasticity (MOE) of C-LVL depends on the species of veneer raw materials, that is, MOE of C-LVL was the same as the MOE of solid lumber of the same species. 2) The number of plies affects the modulus of rupture (MOR) and the mode of failure of C-LVL. It has no effect on MOE. 3) The interlocked grain structure of C-LVL with +-10 degree in alternate layers effectively prevented decrease in MOE of C-LVL compared to that of solid lumber. 4) There was little effect on MOE or MOR by the addition of radial filler in C-LVL with 10 plies or more. 5) The properties in compression is about equal to those in bending. In the compression test, buckling failure was observed. These results show that C-LVL is suitable for structural uses, especially as building and construction posts.

Key Words:cylindrical LVL, laminated veneer lumber, interlocked grain structure, spiral winding method, flexural property