Innovative detailing for shear in concrete using high performance materials

现有的钢筋混凝土抗剪设计模型使用基于应力的构件强度合成方法，从混凝土贡献和基于桁架类比的抗剪钢筋贡献。 这些模型限制了设计中允许的抗剪钢筋的最大强度，以限制破坏时的裂缝宽度。 抗剪钢筋的最大间距由基于内部桁架假设角度的经验规则定义。 自20世纪60年代以来的有限研究表明，当这些标准中的任何一个放宽时，安全设计是可能的。 直接考虑抗剪钢筋应变和间距的改进抗剪承载力模型，将允许经济和安全地使用现代耐用的钢筋材料作为箍筋。

Existing shear design models for reinforced concrete use a stress-based compositional approach to member strength, from both a concrete contribution and from a shear reinforcement contribution based on a truss analogy. These models limit the maximum strength of the shear reinforcement permitted in design, in order to limit crack widths at failure. Maximum spacing of the shear reinforcement is defined by empirical rules based on an assumed angle for the internal truss. Limited studies since the 1960's have shown that safe designs are possible when either of these criteria are relaxed. Improved capacity models for shear that directly consider both the shear reinforcement strains and spacing, will permit economical and safe use of modern, durable reinforcement materials as stirrups.