Development of compressed wood fasteners for timber construction III. Bearing characteristics of compressed LVL plate with a drift-pin

Rotary-cut veneers of sugi (Cryptomeria Japonica D. Don) were impregnated w ith low-molecular weight phenolic resin, and converted into compressed lami nated veneer lumber (LVL) of parallel laminates (P-type) or crossbanded lam inates (C-type) by hot pressing. Tension-type bearing strength tests of dri ft-pin joints were made, to evaluate effect of end-distance, edge-distance and loading angle on bearing characteristics of compressed LVL plate. The r esults were as follows: 1) In loading parallel to the grain (0 degree), P-type plate was split para llel to the grain direction, but C-type plate exhibited a very ductile beha vior, where drift-pin was embedded into compressed LVL prate continuously. In loading perpendicular to the grain (90 degree), not only P-type plate bu t also C-type plate was broken off parallel to the grain direction. In 15, 30 and 45 degree loading, C-type plate exhibited a very ductile behavior. 2) Bearing characteristics of both plate were not changed when end-distance and edge-distance was fixed at 4d (d: diameter of drift-pint or 7d. 3) Bearing constant of compressed LVL plate decreased with increasing cross band veneer at the loading direction. That of P-type prate in 90 degree loa ding was about 40% of that in 0 degree loading. Maximum bearing stress of c ompressed LVL prate decreased gradually with increasing crossband veneer. B ut that of P-type plate in 90 degree loading was exceptionally lower. 4) Bearing characteristics of P-type plate were above 1.5 times as much as the estimated value calculated by density or modulus of elasticity. Those o f C-type plate were also high, and anisotropy of those was very small.