基于MCFT的钢筋钢纤维混凝土深梁受剪承载力计算

Calculation for Shear Capacity of Steel Fiber Reinforced Concrete Deep Beams Based on MCFT

在分析钢筋钢纤维混凝土深梁受剪机理和破坏特征的理论基础上,考虑钢纤维的有效分布,将MCFT运用到钢筋钢纤维混凝土深梁的受剪承载力分析中,并通过已有25根钢筋钢纤维混凝土深梁的试验结果,验证了该理论的可行性.在此基础上,运用MCFT对影响钢筋钢纤维混凝土深梁受剪承载力的因素进行分析.结果表明,混凝土强度对受剪承载力影响最大,受剪承载力随钢纤维体积率和梁底纵向钢筋配筋率的增大均呈先增大然后稍降低最终趋于稳定的特点,竖向分布筋的配筋率小于0. 6%时对受剪承载力的提高作用不如同体积率下钢纤维的提高作用显著,钢纤维长径比的影响作用最小.

Based on the theoretical analysis of the shear mechanism and failure characteristics of steel fiber reinforced concrete deep beams, and considering the effective distribution of steel fibers, the modified compression field theory （MCFT） is applied to the shear capacity analysis of steel fiber reinforced concrete deep beams, and the feasibility of this theory is verified by the test results of 25 existing steel reinforced concrete deep beams. Factors influencing shear bearing capacity of steel fiber reinforced concrete deep beams are analyzed based on MCFT. The results show that concrete strength plays the most important role in shear bearing capacity. With the increase of the volume fraction of steel fiber and the longitudinal reinforcement ratio of beam bottom, the shear bearing capacity increases first and then decreases slightly and maintains stability finally. The contribution of vertical reinforcement to shear bearing capacity is not as volume ratio of steel fiber significantly when the ratio is less than 0.6%. The influence of steel fiber aspect ratio is minimal.