Effect of Fe/Al ratio on electronic structure and mechanical properties of Ca 2 Al x Fe 2− x O 5

Abstract Ca 2 Al x Fe 2− x O 5 is a key constituent of high‐iron, low‐calcium (high ferrite cement) cement, which has broad applications in bridges, marine engineering, and other harsh environments. It is crucial to understand the mechanical properties of Ca 2 Al x Fe 2− x O 5 for assessing the strength and durability of C 4 AF in real‐world scenarios, which are vital for ensuring the quality and safety of engineering structures. The Fe/Al molar ratio directly influences the microstructure and mechanical behavior of Ca 2 Al x Fe 2− x O 5 , but the mechanical properties of Ca 2 Al x Fe 2− x O 5 series solid solutions are scarcely investigated experimentally. In this work, first‐principles calculations were employed to examine the electronic structure, bonding, and mechanical properties of five solid solutions, specifically Ca 2 Al 2 O 5 , Ca 2 Fe 0.5 Al 1.5 O 5 , C 4 AF‐ I , Ca 2 Fe 1.5 Al 0.5 O 5 , and Ca 2 Fe 2 O 5 , were investigated in this study. It was found that a high ratio of Fe/Al solid solution can negatively impact the strength and stiffness of Ca 2 Al x Fe 2− x O 5 solid solution. These results provide a theoretical foundation for designing high‐strength offshore concrete engineering that uses low‐calcium, high‐iron cement as its primary component.