FRP筋混凝土双向板冲切强度公式评估

Evaluation of Punching Shear Strength Equations of Two-way Concrete Slabs with FRP Rebars

为评价现有FRP筋混凝土双向板冲切强度计算公式的精度,采用数理统计的方法对收集到的38组FRP筋混凝土双向板冲切强度试验数据进行评估。结果表明,影响FRP筋混凝土双向板冲切强度的主要因素有混凝土强度、临界冲切截面周长、有效板厚、FRP筋配筋率及其弹性模量、尺寸效应;在所评价的10个计算公式中,规范公式的预测结果大多比较保守,且其精度均低于文献公式;Ospina公式预测结果与试验结果最为接近,且精度最高,预测结果与试验结果比值的均值为1.03,标准差为16.04%,变异系数为15.53%。研究结果为FRP筋混凝土双向板冲切强度计算公式的进一步优化提供了参考。

In order to evaluate the accuracy of the existing formulas for calculating the punching shear strength of FRP reinforced two-way concrete slabs,the mathematical statistical method was used to evaluate the collected 38 sets of experimental parameters for punching shear strength of FRP reinforced two-way concrete slabs.The results demonstrate that the main factors affecting the punching shear strength of FRP reinforced two-way concrete slabs include concrete strength,critical punching section perimeter,effective slab thickness,FRP reinforcement ratio and its elastic modulus,and size effect;Among the 10 evaluated punching shear strength calculation formulas,the prediction results of the formulas by the design specifications are mostly conservative,and their accuracy is lower than the formulas in the literature;The predicted results by the Ospina formula are closest to the experimental results,and its prediction accuracy is the highest.The average ratio of prediction to experimental results is 1.03,the standard deviation is 16.04%,and the coefficient of variation is 15.53%.This study provides a reference for further optimization of the formula for calculating the punching shear strength of FRP reinforced two-way concrete slabs.