The steel fibers were generally used to improve the compressive strength of hybrid fiber reinforced strain hardening cementitious composite (SHCC) due to its higher strength and modulus. It is crucial to rationally design the volume fraction of fibers to maximize the role of different fibers in hybrid fiber reinforced SHCC. In this study, a design philosophy was proposed to guide the synthesis of hybrid fibers reinforced SHCC with saturated multiple cracking. The practical design criteria were determined by the joint use of cracking saturation index and pseudo strain hardening (PSH) performance indices. Finally, the design criteria were used to determine the volume fraction of steel fiber in hybrid fiber reinforced SHCC. Based on the proposed method, the optimum steel fiber volume fraction of 0.68% in hybrid fiber reinforced SHCC with 1.5% volume fraction of PE fibers was obtained for a designated matrix.

钢纤维由于其较高的强度和模量而通常用于提高混合纤维增强的应变硬化水泥复合材料（SHCC）的抗压强度。合理设计纤维的体积分数以最大化不同纤维在混合纤维增强SHCC中的作用至关重要。在这项研究中，提出了一种设计理念来指导具有饱和多重裂纹的混杂纤维增强SHCC的合成。实际设计标准是由裂纹饱和指数和拟应变硬化（PSH）性能指数共同确定的。最后，使用设计准则确定混合纤维增强的SHCC中钢纤维的体积分数。基于提出的方法，混合纤维增强SHCC的最佳钢纤维体积分数为0.68％。