In this study, the effects of metakaolin (MK), as a replacement for the Portland cement, in the ratios of 0%, 10% and 20% by cement weight and steel fiber (SF) dosages of 0%, 0.25%, 0.5%, and 1% by concrete volume were investigated on the microstructure, mechanical properties, durability and global warming potential (GWP) of concrete containing 25% volume percentage of crumb rubber replaced with natural fine aggregates at elevated temperatures. Several specimens were exposed to the high temperatures of 150, 300, 450 and 600 °C for an hour, and were then compared in terms of mass loss, compressive strength, ultrasonic pulse velocity (UPV), splitting tensile strength (STS), and impact resistance at the ambient temperature. The role of MK and SF on the concrete microstructure at high temperatures was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The results show that not only does the combination of MK and SF improve the mechanical properties and durability of rubberized concrete at high temperatures, but it can also introduce more environmentally friendly mixes by reducing CO₂ emissions, compared to a plain concrete mix.

在这项研究中，偏高岭土（MK）的替代效果（按水泥重量的0％，10％和20％）和钢纤维（SF）的比例分别为0％，0.25％，0.5％研究了在混凝土中含有25％（体积）百分比的橡胶粉被天然细骨料代替的混凝土的微观结构，力学性能，耐久性和全球变暖潜能值（GWP）。将几个样品暴露在150、300、450和600°C的高温下一个小时，然后比较质量损失，抗压强度，超声脉冲速度（UPV），抗拉强度（STS）和在环境温度下的耐冲击性。通过扫描电子显微镜（SEM）和X射线衍射（XRD）分析研究了MK和SF在高温下对混凝土微观结构的作用。结果表明，MK和SF的组合不仅改善了高温下橡胶混凝土的机械性能和耐久性，而且还可以通过减少CO引入更环保的混合料。与普通混凝土相比，排放量为₂。