Fatigue behavior of hardened cement paste

Abstract The fatigue behavior of cement hardened paste was studied in compression loading with an R ratio (σ min / σ max) equal to 10. The samples were immersed in water at room temperature. The fatigue life as a function of the stress amplitude, displayed a large scatter. The longitudinal and the radial deformations were recorded. Three stages were revealed. At the beginning of the tests the deformation per cycle increased. A steady, state was then reached, which occupied most of the life of the specimen ; during this stage the longitudinal deformation per cycle was constant whereas there was no axial deformation. The deformation rate increased again at the end of the test just before the specimen shattered to pieces. A very good correlation was found between the fatigue life and the deformation rate per cycle during steady state. The acoustic emission and the ultrasonic waves attenuation displayed the same behavior as the deformation rate.