Evaluation of in-plane shear transfer in developed pca floor slab system for unbonded prestressed concrete frame structure

In this study, a new PCa floor system for an unbonded prestressed concrete (PC) frame structure was developed. Deformation of unbonded PC frame structure is expected to concentrate in the joint between beam and column and. as a result, damage such as cracks to beams and columns can be reduced during an earthquake. Floor slab applied to these structures is needed to be provided with not only sufficient in-plane shear transfer capacity but also system to avoid confinement of movement of beam-column joint, for this purpose, a new PCa slab-beam joint system was proposed and loading tests of full scale specimens were carried out. From the experimental results, it was shown thai shear stiffness and strength in the new joint system with shear cotter were almost same with those in conventional half PCa floor slab. Moreover, an evaluation method of in-plane shear of floor slab between the frames with different stiffness and shear capacity was examined based on equilibrium of shear force in frames and floor slabs. Static push-over and seismic response analyses of prototype frame structures were carried out to discuss the requirement for in-plane shear capacity of floor slab and design shear for slab-beam joint. Significant difference was not found between the seismic responses of frame structures with rigid floor and those with the new floor slab system, provided that the slab-beam joint was designed accordance with the proposed evaluation method of in-plane shear.