Test and analysis on in-plane shear behavior of precast concrete hollow core slabs

Precast concrete hollow core (PHC) slabs are mostly used in industrial and civil buildings because of the low weight and high efficiency of construction. The previous researches are mainly focused on the out-of-plane bending and shear behavior of PHC slabs. However, the in-plane shear behavior of the PHC slabs with highstrength tendons is not fully understood yet. In this regard, to investigate the in-plane shear behavior of PHC slabs, shear tests were conducted on a new long PHC slab with high-strength tendons and a new spliced slab in the present paper. The spliced slab was composed of two PHC short slabs with U-type bars, post-pouring concrete and anchorage bars. Subsequently, finite element models were established and validated by the test. Parametric analysis was conducted on the spliced slab to study the effect of the reinforcement ratio of tendons, concrete strength, tendon prestress, position of loading point, etc. Furthermore, based on the deep beam theory of single generalized displacement, the modified theoretical formulas on the in-plane initial stiffness of the specimens were illustrated. The results show that the mechanical behavior of the spliced slab was better than that of the long slab, including shear capacity, energy dissipation capacity and ductility. The initial stiffness and shear capacity of the spliced slab improved obviously with the reduction of the distance between the supports. The difference between in-plane initial stiffness of the PHC slab obtained from the modified theoretical formulas and that obtained from experiment are within 5%, which means the proposed formula can predict the in-plane initial stiffness of the PHC slabs well. This may provide a reference for the application of the long PHC and spliced slabs in engineering.