Experimental and Numerical Assessment of Timber–Concrete Composite Floor Elements under Static Loading

Sammanfattning

The investigation of new timber–concrete composite (TCC) floor systems has become increasingly relevant, as these systems are being studied as load-bearing solutions with the potential to reduce climate impact by combining renewable timber with concrete in an efficient composite system. This master’s thesis evaluates the structural performance of a TCC floor system with OSB webs designed to accommodate technical installations within the floor depth. Special attention is given to how a 30 mm OSB embedment into the concrete slab affects the structural behaviour, load transfer, slip, stiffness, and composite action of the system. The study includes laboratory tests on two specimens as well as numerical analyses of two different floor-system configurations. Load-bearing capacity, stiffness, slip between components, strain response, energy absorption, and local stress concentrations are investigated, with particular focus on the response of the top chord, bottom chord, and OSB web. The experimental results are compared with a finite element (FE) model developed in ABAQUS, where solid elements are used to assess the model’s ability to describe both global deformations and local stress distributions. The results show that S2-SN, where the OSB panel is embedded 30 mm into the concrete slab, exhibits a stiffer structural behaviour than S1-S. The 55% higher load-bearing capacity indicates that the OSB embedment improved the load transfer and contributed to more effective composite action between the components. This conclusion is supported by the results for deflection, slip, strain, stiffness, and energy absorption. The FE model showed good agreement with the experimental results at the first load level, while larger deviations occurred at higher load levels due to nonlinear behaviour, slip, local damage, and reduced composite action.