Damage Identification of Reinforced Concrete Beam Using Modal Curvature Approach

Reinforced concrete (RC) beams are one of the main load bearing structural elements in buildings. These elements suffer from distress, primarily cracks, due to many reasons resulting into degradation of stiffness and strength. The modal curvature approach is a very good technique in damage identification in steel and RC beams. This study provides a critical review on the different approaches for damage prediction. The current state of the knowledge is presented and the different models which have been proposed in the past for damage identification on structural systems are discussed. In this paper, a technique for damage identification and assessment of RC beams is proposed which makes use of vibration data to compute the Curvature Damage Factor (CDF). To detect damage progression, simply-supported RC beams were subjected to an incrementally increasing static four point loading in steps till ultimate failure. After each load step, vibration measurements were performed using wireless sensors mounted at critical locations. The experimental crack pattern and results of modal curvature were compared. The results show that this approach is efficient for damage identification of reinforced concrete beams which exhibit high non-linear behavior.