Study on the application of post-embedded piezoceramic transducers for crack detection on earthquake-damaged RC columns

Abstract

In this study, the post-embedded piezoceramic transducers are used to perform structural health monitoring (SHM) and detect crack damage on the reinforced concrete (RC) column. The piezoceramic transducers are utilized as actuators and sensors, respectively. To investigate the use of the piezoceramic transducer in detecting crack damage in RC columns, SHM tests are performed on three full-size RC column specimens with various failure modes under cyclic loading. The sensors are installed at two depth ranges (40–50 and 70–80 mm) beneath the surface of the column to investigate the effect of the sensor depth on the damage index. In this study, the energy and amplitude-based damage indexes are developed. Both approaches follow the same trend under various drift ratios of the specimen. However, the value of energy-based damage index is much higher than the amplitude index for all peak drift ratio of the specimen. From different depth range of piezoceramic transducers, this study recommends a depth of 80 mm as optimal for post-embedded piezoceramic transducers, since it receive more stable signals in various frequencies. In the proposed health monitoring approach using piezoceramic transducers, the equation to predict the maximum residual crack width and damage index smart aggregates are developed. The normalized damage index equation which in this study is referred as ‘crack damage index’ is introduced and used to calculate the limiting value for each damage level. The suggested value of the crack damage index for each damage level is also provided. The energy, strength and stiffness reduction factors for each damage level, which correlate with the crack damage index, are also presented. These results demonstrate that the proposed post-embedded piezoceramic transducers has the potential to be used as a tool for SHM on an RC column.