Bearing capacity evaluation of keyed joints in precast-cast-in-place reinforced concrete structures for effective rehabilitation

Abstract In order to effectively rehabilitate buildings and structures and ensure their serviceability, it is important to improve precision of the estimation of the keyed joints ultimate load in prefabricated and prefabricated monolithic structures made of reinforced concrete and their remaining service life. In this direction, the introduction of a general theoretical method for calculating bearing capacity is promising. Adapted to concrete and reinforced concrete apparatus of the plasticity theory, the variational method, and the possible velocities principle are used. The criterion for the plasticity theory application is the condition of simultaneous achievement of the ultimate stresses in the compressed and tensile areas of the failure surface. The kinematic schemes of failure of keyed joints are proposed, which are adopted on the basis of the failure nature study and reflect the behavior of the element in a limit state. Formulas are proposed for calculating the ultimate load of single keyed joints that fail by key shearing, seam shearing along an inclined plane, and splitting of an inclined compressed strip. They allow to fully consider the factors influencing the joints bearing capacity. Results obtained in experiments confirm the theoretical assessment reliability.