Influence of metakaolin as a partial replacement of cement on characteristics of concrete exposed to high temperatures

The ever-increasing construction demand for the human and high energy consumption of the production of the raw material has a significant impact on environmental pollution. One of the challenges facing civil engineers is to understand the behavior of concrete during exposure to elevated temperatures, and their service life performance after exposure. In this study, the possibility of partial replacement of cement with metakaolin on the improvement of concrete properties is investigated. The dosage of metakaolin is 10, 15, and 20% of cement weight. After determining the optimum percentage of metakaolin at ambient temperature, the specifications of the specimens are tested at temperatures of 28–800 °C. Although high temperatures damage the mechanical and durability characteristics of normal concrete, the substitution of 15% of cement weight with metakaolin can be recommended as a practical solution to improve the mechanical and durability properties of concrete exposed to elevated temperatures.