Wireless damage monitoring of concrete structures. (Credit: Dr. Costas Providakis, Bentham Science Publishers)
Structural Health Monitoring (SHM) plays a significant role in evaluating the structural integrity of concrete structures because many of the expected construction requirements will have to be adapted on existing structures with common signs of deterioration.
The electromechanical impedance (EMI) sensing approach is a potential alternative experimental method for the damage detection of concrete structures even at early stages. The proposed wireless monitoring system, indicated as Wireless impedance or Admittance Monitoring System (WiAMS), maintains the advantages of low-budgeted EMI-based monitoring system, but not limited by the sampling rate of data acquisition device in standard EMI monitoring systems.
This can be attained by using a credit card-sized Raspberry Pi single-board computer that has all of the capabilities to transfer data without a base station and perform processing-hungry operations, such as video streaming, by just adding WiAMS to the home network and carry out SHM.
In addition, the use of the Raspberry Pi single-board computer expands the existing hardware interfaces and makes the sensing device be used as an SHM control unit as well as a base station for various other sensing platforms such as motion with audio, video or environmental sensors.
WiAMS also provides extensive features like remote control, email notifications, wireless data upload to an SQL database, scheduled and iterative impedance or admittance measurements, high processing power and frequency spans from 5 to 300 kHz with resolution down to 1 Hz.
The proposed WiAMS device can be successfully applied on different concrete specimens for detecting damage even at very early stages by setting up a damage identification index derived from extreme value statistics.