钢纤维高强混凝土方形冲切板的变形与强度

DEFORMATION AND STRENGTH OF STEEL FIBER HIGH-STRENGTH CONCRETE SLABS SUBJECTED TO PUNCHING SHEARS

通过试验 ,研究钢纤维高强混凝土方形冲切板的变形和强度性能 ,认为板在冲切破坏之前发生的变形主要是弯曲变形 ,该变形反映了板在各个受力阶段的抗弯性能 ,也在很大程度上直接影响着冲切锥面上的应力分布和板面钢筋的抗冲切能力。对方形冲切板在各个受力阶段的挠度进行了计算 ,并在分析试验结果的基础上 ,建立了考虑受弯变形的冲切破坏机构 ,提出板的极限强度由冲切锥抗冲切力和板的部分抗弯能力组成。对冲切板变形和强度的计算结果与实测值吻合良好。

The deformation and strength of steel fiber high-strength concrete square slabs subjected to punching shears are investigated through tests. The authors point out that the deformation of a slab prior to punching shear failure is caused by bending moment. The deformation not only reflects the flexure behavior of the slab at every loading stage, but also affects the stress status on the surface of the punching shear cone and the ultimate capacity of the slab. In this paper, the deformations of the slabs at three loading stages prior to failure are calculated and the collapse mechanism considering the bending deformation of a slab is established. The authors also point out that the ultimate strength of a punching-shear slab includes the punching capacity of the failure cone and a part of the flexure strength of the slab. The comparison shows good agreement between the theoretical values and the testing curves.