This open access book presents key findings from the German Research Foundation’s priority program SPP 2020, offering insights into the fatigue behavior of high-strength and ultra-high-strength concretes, including fibre-reinforced types. Readers will discover how advanced experimental and computational methods were used to investigate damage mechanisms under cyclic loading, with a focus on understanding and predicting the material degradation across multiple scales—knowledge that supports the design of more durable and efficient concrete structures.