The shear span-to-effective depth ratio (a/d) is one of the factors governing the shear behavior of reinforced concrete (RC) beams, with or without shear reinforcement. In high-strength concrete (HSC), cracks may propagate between the aggregate particles and result in a brittle failure which is against the philosophy of most design guidelines. The experimental results of six HSC beams, with and without shear reinforcement, tested under four-point bending with a/d ranged from 2.0 to 3.0 are presented and compared with different model equations in design codes. The a/d ratio has higher influence on the shear strength of reinforced HSC beams without shear reinforcement than beams with shear reinforcement. Most of the shear resistance prediction models underestimate the concrete shear strength of the beams but overpredict shear resistance of beams with shear reinforcement. However, the fib Model code 2010 accurately predicted the shear resistance for all the beams within an appropriate level of approximation (LoA).

剪切跨度与有效深度之比（a / d）是控制钢筋混凝土（RC）梁在有无钢筋情况下的抗剪性能的因素之一。在高强度混凝土（HSC）中，裂纹可能在集料颗粒之间传播，并导致脆性破坏，这违反了大多数设计准则的理念。提出了六种带或不带剪切补强的HSC梁在a / d为2.0至3.0的四点弯曲下的试验结果，并与设计规范中的不同模型方程进行了比较。该A / d比例对没有剪切增强的钢筋混凝土HSC梁的抗剪强度的影响要大于有剪切增强的钢筋混凝土。大多数抗剪强度预测模型都低估了梁的混凝土抗剪强度，但过高地预测了具有剪力加固的梁的抗剪强度。但是，fib型号代码2010在合适的近似值（LoA）范围内准确预测了所有梁的抗剪强度。