Fire is detrimental to skyscrapers. Lightweight high-performance concrete (L-HPC) developed by combining lightweight microspheres and ultra-high-performance concrete binder is promising for future mega infrastructure projects. This study investigates the fire resistance of lightweight high-performance cementitious composites developed using hollow ceramic microspheres (HCMs) and hollow glass microspheres (HGMs) at different temperatures. Experimental results show that incorporating lightweight microspheres significantly increases the residual compressive strength of L-HPC by maintaining those of HGMs and HCMs groups at 92 % and 78 %, respectively, at 900 °C. Furthermore, these lightweight microspheres effectively mitigate thermal spalling and crack propagation in L-HPC. Microstructural analysis indicates that the lightweight microspheres facilitate steam-pressure release. The melting of HGMs realizes interconnections in the pore channel, which are subsequently strengthened by HGM and matrix-binder reactions. The HCMs feature perforated shells that provide inert and high-temperature-resistant steam channels. This study confirms that L-HPC developed using the abovementioned strategy exhibits excellent fire resistance.

中文翻译：

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利用空心微球增强轻质高性能水泥基复合材料的耐火性能


火灾对摩天大楼有害。通过将轻质微球和超高性能混凝土粘合剂相结合而开发的轻质高性能混凝土 （L-HPC） 有望在未来的大型基础设施项目中发挥作用。本研究研究了使用空心陶瓷微球 （HCM） 和空心玻璃微球 （HGM） 开发的轻质高性能水泥基复合材料在不同温度下的耐火性能。实验结果表明，在 900 °C 下，掺入轻质微球通过将 HGMs 和 HCMs 组的残余抗压强度分别保持在 92% 和 78%，显著提高了 L-HPC 的残余抗压强度。 此外，这些轻质微球可有效减轻 L-HPC 中的热剥落和裂纹扩展。微观结构分析表明，轻质微球有利于蒸汽压力释放。HGM 的熔化实现了孔通道中的互连，随后通过 HGM 和基质-粘合剂反应加强了这种互连。HCM 具有多孔外壳，可提供惰性和耐高温的蒸汽通道。本研究证实，使用上述策略开发的 L-HPC 表现出优异的耐火性。