Experimental study of the response to fatigue compression and indirect tensile loading in high-technology concrete

This study examines the fatigue behavior of high-technology concrete reinforced with steel fibers under compressive and indirect tensile loading through an extensive experimental campaign. Compression fatigue tests, conducted at varying stress levels and constant frequency, revealed a probabilistic fatigue life modeled by a Weibull distribution, with significantly longer lifetimes observed at lower stress ranges. The secondary strain rate per cycle exhibited a linear relationship with cycles to failure, consistent with Sparks and Menzies’ law across all stress levels. Indirect tensile fatigue tests employed a two-phase approach, highlighting Weibull-distributed fatigue life during the second damage phase. Digital image correlation (DIC) captured strain fields, showing that cracks initiated at the matrix, propagated in mode I fracture patterns from the specimen center to the load application points, and stabilized as strain accumulation plateaued. Failure mechanisms were dominated by excessive crack opening and crushing wedge formation at the specimen ends. A novel indirect tensile test configuration provided detailed insights into fatigue processes, emphasizing the importance of strain evolution and crack propagation dynamics in high-technology concrete. The findings validate Sparks and Menzies’ law as a robust framework for correlating fatigue life with strain rates and refine experimental methodologies for dynamic concrete behavior analysis.