Experimental and numerical investigations on fatigue damage propagation and life prediction of high-performance concrete containing reactive mineral admixtures

The effects of reactive mineral admixtures (fly ash and ground slag) on damage propagation and fatigue life of concrete are deeply investigated by experiments and numerical simulations based on high-resolution digital images of the actual concrete microstructure. Four-point bending experimental fatigue tests are performed, where the evolution of the damage is followed using a real-time detection method. The initiation and propagation of micro-cracks and fatigue damage of concrete are predicted by the improved lattice model, and the modeling results are consistent with the experimental ones. Furthermore, the modeling and experimental results show that, by adding fly ash and ground slag to concrete, the fatigue crack propagation and damage accumulation under high/low stress levels change with respect to those related to concrete without admixtures, and the fatigue behavior of the material with such admixtures improves.