A thermodynamic framework for fatigue crack growth in concrete

• Analytical expression for dissipation potential for concrete is proposed.
• Physical meaning is imparted to the dissipation potential.
• Fatigue crack propagation model for concrete is derived from first principles.
• The use of normalized dissipation potential as a damage indicator is suggested.

The phenomenon of fatigue is commonly observed in majority of concrete structures and it is important to mathematically model it in order to predict their remaining life. An energy approach is adopted in this research by using the framework of thermodynamics wherein the dissipative phenomenon is described by a dissipation potential. An analytical expression is derived for the dissipation potential using the concepts of dimensional analysis and self-similarity to describe a fatigue crack propagation model for concrete. This is validated using available experimental results. Through a sensitivity analysis, the hierarchy of importance of different parameters is highlighted.