Steel-basalt hybrid fibers reinforced cement-based composites (SBFRCC) have excellent mechanical properties at ambient temperature. Conducting research on the behavior of SBFRCC at high temperatures is beneficial for applications in structures which may be exposed to fires. In this study, the physical properties of fibers and mechanical properties of SBFRCC exposed to high temperatures were assessed through appearance, mass loss, and compressive, flexural, and splitting tensile strength tests. The deterioration mechanism was studied by X-ray diffraction (XRD), simultaneous thermal analysis (STA), and scanning electron microscopy (SEM). The results show that the color and mass of steel and basalt fiber change significantly with temperature. The addition of steel fiber and basalt fiber can improve residual flexural strength and splitting tensile strength. High basalt fiber content is harmful for compressive strength. The compressive, flexural, and splitting tensile strength of SBFRCC essentially decreases with temperature. Models were established to describe the quantitative relationship between relative strength and fiber content, temperature. The addition of steel fiber and basalt fiber can effectively inhibit cracks generation and propagation by multi-stage cracking resistance. High temperature deterioration of hybrid fibers can only reduce the reinforcement, but steel fiber and basalt fiber can still play a role in bridging cracks at 900°C.

钢-玄武岩混合纤维增强水泥基复合材料 (SBFRCC) 在环境温度下具有优异的力学性能。对高温下 SBFRCC 的行为进行研究有利于在可能暴露于火灾的结构中的应用。在这项研究中，通过外观、质量损失以及压缩、弯曲和劈裂拉伸强度测试来评估暴露于高温下的 SBFRCC 的纤维物理性能和机械性能。通过X射线衍射(XRD)、同时热分析(STA)和扫描电子显微镜(SEM)研究了劣化机理。结果表明，钢和玄武岩纤维的颜色和质量随温度发生显着变化。添加钢纤维和玄武岩纤维可以提高残余抗弯强度和劈裂抗拉强度。玄武岩纤维含量高对抗压强度有害。SBFRCC 的抗压、抗弯和劈裂抗拉强度基本上随温度降低。建立模型来描述相对强度和纤维含量、温度之间的定量关系。钢纤维和玄武岩纤维的加入，通过多级抗裂，可有效抑制裂纹的产生和扩展。混合纤维高温劣化只能降低补强性，但钢纤维和玄武岩纤维在900℃仍能起到弥合裂缝的作用。SBFRCC 的劈裂抗拉强度随温度的升高而降低。建立模型来描述相对强度和纤维含量、温度之间的定量关系。钢纤维和玄武岩纤维的加入，通过多级抗裂，可有效抑制裂纹的产生和扩展。混合纤维高温劣化只能降低补强性，但钢纤维和玄武岩纤维在900℃仍能起到弥合裂缝的作用。SBFRCC 的劈裂抗拉强度随温度的升高而降低。建立模型来描述相对强度和纤维含量、温度之间的定量关系。钢纤维和玄武岩纤维的加入，通过多级抗裂，可有效抑制裂纹的产生和扩展。混合纤维高温劣化只能降低补强性，但钢纤维和玄武岩纤维在900℃仍能起到弥合裂缝的作用。