Prognosis of Damage Intensity on Reinforced Concrete Beam Under Cyclic Loading

Active damage such as crack initiation owing to cyclic loading in reinforced concrete beams is a pivotal global phenomenon. This damage is because the crack initiation is slowly generated in the structure and cannot be observed visually. As the cyclic load progresses, the cracks need to be classified. This paper presents the prognosis of damage intensity on reinforced concrete beams under cyclic loading. Twelve singly reinforced concrete beams were prepared for the purpose of testing. The beams were subjected to three point loading with six phases of maximum cyclic loading. The acoustic emission technique was utilised for monitoring the crack progression. For cyclic loading, the 1 Hz frequency and sinusoidal wave mode were utilised. For each phase of loading, 5000 cycles were applied. A zone intensity chart was used for classifying the cracks that occurred in the beams. The classification was constructed based on the acoustic emission signals collected from the located events and on a channel basis. The located events were concentrated on the critical sections of SEC A and SEC B. Meanwhile, for the channel basis, the closest sensor to critical sections was used from CH3. It was found that the prognosis of the active crack intensity in the beam can be identified, which closely corresponds to the load increment. This study is useful for understanding crack behaviour in a beam subjected to cyclic loading.