Mechanical properties of steel-reinforced wood and wood-based structural beams

This study aimed to evaluate the mechanical properties of structural beams made of different materials. The glulam (GL), pine sawn timber/lumber (CL), laminated veneer lumber (LVL) and oriented strand lumber (OSL) beams were tested. Both low-grade sawn timber and wood chip materials do not possess the high properties that match those of materials such as LVL. Therefore, it was proposed to reinforce the tension zone of the manufactured beams with steel tendons. The quality of the manufactured beams was assessed using a four-point bending test in accordance with EN 408 standard. A nearly 80% increase in the static bending strength of OSL beams was obtained. A comparable increase in strength was obtained for GL beams. However, in their case, the scatter of results around the mean value was very large. Slightly lower values than expected were obtained for beams made from post-use sawn timber. Despite the stiffness of these beams being 7% lower than expected, their static bending strength was not statistically different from that of GL. The strength of these beams was approximately 65 N/mm2, compared to 57 N/mm2 obtained for OSL beams and 81 N/mm2 for LVL beams.