Fatigue damage in cement and concrete refers to the progressive and irreversible deterioration that occurs in these materials under repeated loading. This type of damage typically manifests as microcracks that initiate and grow due to fluctuating stress cycles over time, eventually leading to macroscopic fractures and structural failure. Fatigue damage is a critical consideration in the design and maintenance of concrete structures subjected to dynamic loads, such as bridges, pavements, and buildings in seismic zones.