Carbonated MgO-based Engineered Cementitious Composite (ECC) has ultrahigh tensile ductility and tight crack width control behavior. However, the expectation of improved fire-resistant has not been confirmed. This study explored the alterations to mechanical and microstructure characteristics of this material after exposure to temperatures up to 500 °C. Material mass loss, compressive strength, tensile strength, strain capacity, and matrix fracture toughness were measured. Scanning electron microscopy, mercury intrusion porosimetry, thermogravimetric analysis, and X-ray diffraction were used to probe the degradation of the cement matrix and fibers. The effect of elevated temperature on carbonated MgO-based ECC was further assessed via examination of the micromechanical behavior of the fiber-matrix. The objective of this research was to assess the performance of carbonated MgO-based ECC exposed to fire hazards. The tensile ductility of carbonated MgO-based ECC was found to be enhanced when exposed to ∼100 °C as compared with those at room temperature ∼20 °C. Further increase in exposure temperature, however, posed a negative impact on the composite compressive strength, ultimate tensile strength, and ability to control crack width. The results provide a useful database for further investigations into carbonated MgO-based ECC for fire safety enhancement.

碳酸镁基工程水泥基复合材料 (ECC) 具有超高的拉伸延展性和严格的裂纹宽度控制行为。然而，提高耐火性的预期尚未得到证实。本研究探讨了这种材料在暴露于高达 500 °C 的温度后机械和微观结构特性的变化。测量了材料质量损失、压缩强度、拉伸强度、应变能力和基体断裂韧性。使用扫描电子显微镜、压汞法、热重分析和 X 射线衍射来探测水泥基体和纤维的降解。通过检查纤维基质的微机械行为，进一步评估了高温对碳酸化 MgO 基 ECC 的影响。本研究的目的是评估暴露于火灾危险中的碳酸镁基 ECC 的性能。与室温~20°C 相比，碳化 MgO 基 ECC 的拉伸延展性在~100°C 时得到增强。然而，暴露温度的进一步升高对复合材料的抗压强度、极限抗拉强度和控制裂纹宽度的能力产生了负面影响。结果为进一步研究碳酸氧化镁基 ECC 以增强消防安全提供了有用的数据库。对复合材料的抗压强度、极限抗拉强度和控制裂纹宽度的能力产生负面影响。结果为进一步研究碳酸氧化镁基 ECC 以增强消防安全提供了有用的数据库。对复合材料的抗压强度、极限抗拉强度和控制裂纹宽度的能力产生负面影响。结果为进一步研究碳酸氧化镁基 ECC 以增强消防安全提供了有用的数据库。