An experimental study on the bending fatigue behavior of concrete beams by a proposed machine

Cyclic loading can induce brittle fractures at stress levels below the strength threshold, prompting extensive experimental and numerical investigations into the fatigue characteristics of various elements. This study introduces a purpose-built machine designed to empirically explore the fatigue behavior of concrete beams. The proposed machine employs a rotational beam system with a consistent load applied to the beam’s end. By placing a single point on the rotating beam, cyclic flexural moments are generated, inducing maximum tensile stresses at the support. This machine enables continuous long-term testing, adjustment of load amplitude and loading frequency, and tracking the number of cyclic loads until specimen failure. The stress-number cyclic loading test is performed on diverse samples of both reinforced and unreinforced concrete beams. Furthermore, the study assesses the impact of loading frequency …