Structural Health Monitoring of a Reinforced Concrete Frame using Piezoceramic based Smart Aggregates

摘要

This paper reports the experimental results of structural health monitoring of a 2-story reinforced concrete frame using piezoceramic based smart aggregates.The proposed smart aggregate is formed by embedding a water-proof piezoelectric patch with wire leads into a small concrete block,which offers structural protection to the piezoelectric patches.The smart aggregates are embedded at the desired locations in the reinforced concrete frame before casting.In the proposed active sensing method,one embedded piezoelectric patch in a smart aggregate is used as an actuator to generate ultrasonic waves to propagate inside the concrete structures,and the embedded piezoelectric patches in other smart aggregates are used as sensors to detect the propagation wave signal.Wavelet packet analysis is used to analyze the recorded sensor signals.A damage index is formed on the basis of the wavelet packet analysis.In the previous research,the authors have applied the smart aggregates to one-dimensional beam type structures for health monitoring purpose,and in this research,the smart aggregates are used in a 2-story reinforced concrete frame.A total of 16 smart aggregates are used and most of them are installed in the critical regions,where damages are likely to occur.A destructive pushover test is conducted on the 2-story reinforced concrete frame.Experimental results show that the proposed smart aggregate technology along with the developed damage index is able to capture the onset and severity of the major cracks in the structure and is able to offer both local and global structural damage analysis.This research provides valuable preliminary results and also demonstrates the potential to implement the proposed smart aggregate technology to reinforced concrete structures for health monitoring purpose.