A Fatigue Crack Propagation Model for Concrete–Concrete Interface Using Principles of Thermodynamics

During mass concreting and repair work, there is always a formation of a concrete–concrete interface which is known to be a weaker zone due to a mismatch in elastic properties on either side of the interface. There is a greater chance of failure due to the sudden change in stress concentration along the interface. Since most of the concrete structures are subjected to fatigue loading, it is essential to mathematically model the interfacial fatigue crack propagation to predict the remaining life of structures. A significant amount of work has been done on interfacial crack propagation under static loading, but only limited attempts are made on the same under fatigue loading. Considering the complexity in modeling fatigue crack propagation, an energy approach using principles of thermodynamics is adopted in this work. An expression for the dual of dissipation potential for the concrete–concrete interface has been derived using the concepts of dimensional analysis and self-similarity. A fatigue crack propagation law is obtained from the derived dual of dissipation potential and the model is calibrated using experimental results.