Concrete structures are more popular than other types of structures because they have special and non-recyclable material, which keeps them stable against the destruction factors like fire and heat. According to the previous study, calcium aluminate cement has higher compressive strength and higher modulus of elasticity than Portland cement in the temperature range of 20 to 800 degrees Celsius. The purpose of this study is to investigate the mechanical properties of calcium aluminate cement concrete-based and determine the optimal percentage of metakaolin as cement materials substitute at temperatures of 110, 600 and 800 degrees Celsius. Therefore, 5 designs include 0, 5, 10, 15 and 20% of metakaolin instead of calcium aluminate IRC40 cement were used to make 135 specimens, with cubic compressive specimens 10 × 10 × 10 cm, cylindrical tensile specimens with a diameter of 10 and height of 20 cm, and a flexural beam with dimensions of 32 × 8 × 6. The experimental results show that the addition of metakaolin in all specimens developed the mechanical properties. In other words, to demonstrate the best performance in experiments the rate of 10 to 15% of metakaolin replaced calcium aluminate cement.