Experimental investigation on the flexural and shear behaviour of LVL I-beam strengthened with steel channels

Laminated veneer lumber (LVL) has been used as beams in small timber buildings. This study develops a novel I-shaped LVL beam strengthened with cold-formed thin-walled steel channels. The characterisation tests determine the mechanical strengths of LVL and steel. Then, 18 steel strengthened LVL I-beams are prepared with different section parameters and span ratios. The bending and shear tests are performed to evaluate the flexural and shear behaviour of the beam under static monotonic loading, respectively. The failure mechanisms, deformations, load-carrying capacities, and strain distributions are analysed based on the test phenomena and data. The influence of section parameters, slip between LVL and steel, and beam span ratio on the flexural and shear behaviour of the beam are discussed. Finally, the theoretical equations calculate the mid-span deflection, flexural capacity, and shear capacity of the beam. The result shows that (1) the LVL I-beam strengthened with steel channels offers an economic enhancement of stiffness and strength to resist flexural and shear loading; (2) the LVL-steel slip effect reduces the stiffness of the beam; (3) the theoretical results are in good agreement with the experimental results.