Material and Size Effect on Fatigue Damage of Concrete for Pavement Application

Abstract

Highway pavements need to withstand repeated and varying traffic loads due to which they may fail at a stress level lower than their strength called fatigue. Fatigue is the progressive damage due to propagation of cracks and is considered to be the primary cause of structural failure in concrete pavement. The propagation of cracks in concrete is resisted by the fracture toughness, which is a material property. Stress intensity factor is used to express the fracture toughness which depends upon the present state of crack tip stress, strength and geometry of the structural component. Material fracture toughness and the applied stress ratio influence the progressive damage and the fatigue life of concrete. This paper investigates analytically the progressive damage of concrete due to cyclic loading based on a stress intensity factor based fatigue damage prediction model. The effects of material property and specimen size have found to affect the propagation of cracks and the incremental damage. The varying sequence of cyclic loading has found to influence the progressive damage and fatigue life of concrete significantly.