无腹筋钢纤维混凝土梁抗剪承载力的研究

Study on shear capacity of steel fiber reinforced concrete beams without web reinforcement

由于无腹筋钢纤维混凝土梁抗剪承载力受到诸多因素的相互影响,至今还没有得到一个精度高的计算公式。本文收集了192根无腹筋钢纤维混凝土梁的试验数据,通过对试验数据及现存公式的分析,总结了现有的无腹筋钢纤维混凝土梁的抗剪承载力计算公式,对比分析了各公式考虑的参数,并通过对比其计算值与试验值得出了各计算公式的精确度。结果显示各公式的精确度均不高。本文通过理论推导以及数据拟合,得到了斜裂缝倾角的显式计算公式,并提出了无腹筋钢纤维混凝土梁的抗剪承载力简化计算公式。该公式综合考虑了剪跨比、纵筋配筋率、混凝土抗压强度、钢纤维体积含量等重要因素的影响。通过对比分析,本文提出的计算公式与试验值吻合较好。

Since the shear capacity of steel fiber reinforced concrete beams without web reinforcement is influenced by many factors,a formula with high accuracy has not been obtained up to now.In this paper,the experimental data of 192 steel fiber concrete beams without web reinforcement are collected,the formulas for the shear capacity of existing steel fiber reinforced concrete beams without web reinforcement are summarized,the parameters considered by each formula are comparatively analyzed,and the experimental value and the calculated value are compared to verify the accuracy of each calculation formula.The results show that the accuracy of each formula is not high enough.In this paper,the calculation formula for the display of oblique crack dip angle is obtained through the theoretical derivation and data fitting,and the simplified calculation formula for the shear capacity of steel fiber reinforced concrete beams without web reinforcement is proposed.This formula comprehensively considers the influence of factors such as shear span ratio,reinforcement ratio of longitudinal reinforcement,concrete compressive strength,and volume content of steel fibers.Through comparative analysis,the calculation formula proposed in this paper agrees well with the experimental values.