Fatigue performance of strain hardening cementitious composites under tensile and compressive loading

Abstract This study investigates the fatigue behavior of Strain-Hardening Cementitious Composites (SHCC) reinforced with Ultra-High Molecular Weight Polyethylene (UHMWPE) fibers under cyclic compression and tension. The research characterizes fatigue life, deformation evolution and stiffness degradation to support structural applications where fatigue is critical. Compression tests were performed on cylinders at stress levels ( S ) of 50, 70, 80, and 90% of the average monotonic strength. Direct tensile fatigue tests used dogbone specimens at stress levels of 70, 80, and 90%, evaluated under two distinct initial strain states (1 and 3%). All tests used a frequency of 6Hz, stress ratio ( R ) of 0.3. The tests were interrupted upon specimen failure or at a limit of 10 6 cycles. While SHCC’s compressive fatigue life was similar to that of conventional concrete, its high tensile deformation capacity, up to 10%, significantly enhanced its fatigue life in tension. In compression, the S = 0.50 level ensured mechanical stability without significant damage. In tension, levels of 70 and 80% resulted in stable responses, with most specimens reaching the 10 6 cycle limit without failure. Deformation and stiffness degradation analysis revealed distinct damage mechanisms depending on the applied stress level and initial strain state. The research highlights the high capacity of UHMWPE-SHCC to withstand mechanical degradation under cyclic loading, even at elevated stress levels. The stability observed at service-load levels (up to 80% in tension) demonstrates that SHCC is a promising candidate for structural applications requiring high fatigue resilience and reliable service limit state performance.