Prestressed glulam timbers reinforced with steel bars

This paper discusses a series of four-point bending tests that were conducted to failure on unreinforced, reinforced and reinforced-prestressed glue laminated (glulam) timber beams with steel-bars in a simply-supported scheme to determine their flexural behavior. The cross sectional ratio between the steel and the wood was 0.82%. To increase the level of reinforcement, some reinforced beams were prestressed by applying a moderate force to the lower bar. The experimental and numerical data provided the load-deflection, load-strain relationships and strain profiles of the tested beams. The results of the reinforced beams showed that the mechanical strength, the load-carrying capacity and the stiffness for both the simple and prestressed beams were enhanced compared to the unreinforced beams. For the simply reinforced beams, the stiffness increased by 25.9%, the ultimate load increased by 48.1% and the ductility increased by 43.8%. For the reinforced and prestressed beams, the stiffness increased by 37.9%, the ultimate load increased by 40.2%, and the ductility increased by 79.1%. (C) 2011 Elsevier Ltd. All rights reserved.