Behaviour of existing reinforced concrete slabs: tests vs. structural analysis

Reinforced concrete slabs are versatile structural elements used in most types of structures. This work focuses on comparing analytical models with actual structural behaviour. Four segments of a road tunnel deck, composed of prefabricated and cast-in-situ elements, were extracted for laboratory testing. Each segment was subjected to force-controlled loading, and results were recorded in the form of force-deflection curves. The segments were examined to determine geometry, reinforcement layout in both longitudinal and transverse directions, and material properties of concrete and steel. A finite element model was developed in ANSYS Workbench to simulate the same loading conditions. The results show variability in structural response: one sample demonstrated full continuity of the deck, one exhibited medium continuity, and two showed low continuity. These findings suggest that the joints between prefabricated and cast-in-situ elements have variable effectiveness, potentially due to localized damage, construction imperfections or transient loads during extraction and transportation. Further investigation is necessary to improve the accuracy of numerical models.