Efficacy and Damage Diagnosis of Reinforced Concrete Columns and Joints Strengthened with FRP Ropes Using Piezoelectric Transducers

Abstract

Recent research has indicated that the implantation of a network of piezoelectric transducer patches in element regions of potential damage development, such as the beam–column joint (BCJ) area, substantially increases the efficacy and accuracy of the structural health monitoring (SHM) methods to identify damage level, providing a reliable diagnosis. The use of piezoelectric lead zirconate titanate (PZT) transducers for the examination of the efficiency of an innovative strengthening technique of reinforced concrete (RC) columns and BCJs is presented and commented on. Two real-scale RC BCJ subassemblages were constructed for this investigation. The columns and the joint panel of the second subassemblage were externally strengthened with carbon fiber-reinforced polymer (C-FRP) ropes. To examine the efficiency of this strengthening technique we used the following transducers: (a) PZT sensors on the ropes and the concrete; (b) tSring linear variable displacement transducers (SLVDTs), diagonally installed on the BCJ, to measure the shear deformations of the BCJ panel; (c) Strain gauges on the internal steel bars. From the experimental results, it became apparent that the PZT transducers successfully diagnosed the loading step at which the primary damage occurred in the first BCJ subassemblage and the damage state of the strengthened BCJ during the loading procedure. Further, data acquired from the diagonal SLVDTs and the strain gauges provided insight into the damage state of the two tested specimens at each step of the loading procedure and confirmed the diagnosis provided by the PZT transducers. Furthermore, data acquired by the PZT transducers, SLVDTs and strain gauges proved the effectiveness of the applied strengthening technique with C-FRP ropes externally mounted on the column and the conjunction area of the examined BCJ subassemblages.

Cracking and Fiber Debonding Identification of Concrete Deep Beams Reinforced with C-FRP Ropes against Shear Using a Real-Time Monitoring System

“…Eventually, the changes caused in the specimen through the progressive loading process led to modifications to the position and the shape of the acquired voltage responses compared to the pristine condition. Consequently, it could be assumed that the peak frequency response alterations measured at the end of each loading step depict the material’s damage state in the transducer’s contiguity [ 53 ].…”

“…In addition, strain gauges are locally limited, while PZT transducers can act in a wide spatial region. However, a combination of both methods could exhibit supplementary data for verifying the attained data [ 53 ].…”

Fiber Reinforced Polymer Debonding Failure Identification Using Smart Materials in Strengthened T-Shaped Reinforced Concrete Beams

“…The recently developed technology of SHM for RC structures focuses on identifying premature debonding of FRP strengthening materials [ 41 ]. Several studies investigate the ability of PZT transducers to identify the interfacial damage between FRP laminates and concrete as flexural reinforcement in the bottom surface of the specimens [ 42 , 43 , 44 , 45 ].…”

“…According to the above literature review, although research has been conducted in the direction of FRP debonding damage detection utilizing SHM systems based on a variety of methods, there is no generally accepted, reliable system that can be utilized in practice. In previous investigations, the authors proposed a wireless SHM system, which demonstrated promising results in damage detection of reinforced concrete [ 27 , 28 ], fiber reinforced concrete [ 35 ], and reinforced concrete strengthened with FRP ropes [ 41 ]. The successful application of this system toward the detection of damage due to FRP sheet debonding could verify to the system’s ability to identify a wide range of different types of damages and possibly lay the groundwork for its use in real structures.…”

Degradation Feature Extraction Method for Prognostics of an Extruder Screw Using Multi-Source Monitoring Data

“…Structural health monitoring (SHM) has been employed in various fields as a cost-effective maintenance strategy based on sensing systems, such as acoustic emission [ 1 , 2 ], piezoelectric [ 3 , 4 ], vibration [ 5 , 6 ], and multi-source sensors [ 7 , 8 , 9 ]. SHM data are utilized in diagnostics and prognostics.…”