Flexural behavior of precast concrete hollow-core slabs with high-strength tendons

Abstract

Precast concrete hollow core (PHC) slabs have been widely used in brick and concrete structures of rural buildings due to their economic and rapid construction in China. A new PHC slab with high-strength tendons and spliced slab made of the short slabs were proposed in this paper. To investigate the flexural behavior of the slabs, full-scale tests were conducted on three PHC slabs, including one long slab and two spliced slabs with side beams. In detail, the spliced slab was assembled by two short slabs through U-type bars, anchorage bars, and post-pouring concrete. The mechanical properties of specimens were evaluated including the failure modes, strain of concrete and bars, flexural capacity and deflection. The tests results shows that the flexural performance of the spliced slab is close to that of the long slab. Subsequently, finite element models were established and validated by the test data. Based on the validated models, an additional specimen made up of long slab and side beams, was studied to further verify the reliability of the spliced slab. And parametric analysis were carried out on the spliced slab to investigate the influence of prestress of tendons, diameter of tendons, concrete strength, etc. Moreover, the cracking and failure moment of the slabs were calculated by the formulas of GB50010 and ACI318, respectively. The calculated results were compared with the test and simulation results. The results proves that the prediction values calculated by the codes on the flexural capacity of the spliced slab is not conservative. Therefore, considering a reduction factor to correct the results calculated by the codes is necessary.