Evaluation of the mechanical behaviour of novel latticed LVL-webbed joists

Abstract

The mechanical behaviour of a novel I-joist having a latticed Laminated Veneer Lumber (LVL) web is investigated. A total of 30 joists with C24 Grade flanges and latticed LVL webs were manufactured and tested to failure. Two joists depths of 241 mm and 305 mm are examined with flange sections of 60 x 50 mm2 and 65 x 55 mm2, respectively. Two different adhesive types are used to manufacture the LVL webs, namely, urea formaldehyde (UF) and phenol resorcinol formaldehyde (PRF). The failure behaviour was typically linear elastic to failure. The PRF adhesive performed best in moment shear capacities. Tests have shown that the use of latticed LVL-webbed I-Joists can outperform some commercially available I-joists of similar dimensions with the added advantage of having openings within the web to allow services pass through without affecting the structural integrity of the joist.