Wireless strain and temperature monitoring in reinforced concrete using Surface Acoustic Wave (SAW) sensors

TL;DR

This paper demonstrates the feasibility of using passive wireless Surface Acoustic Wave sensors mounted on steel rebars for continuous, cable-free monitoring of strain and temperature in reinforced concrete structures.

Contribution

It presents an initial feasibility study showing that commercial SAW sensors can measure deformation and temperature in concrete without embedded electronics or cables.

Findings

Successful measurement of concrete beam deformation under load

Continuous temperature monitoring over three weeks

Passive wireless sensing eliminates need for cables or electronics

Abstract

Monitoring the health of civil engineering structures using implanted deformation, temperature and corrosion sensors would further improve maintenance and extend the service life of those structures. However, sensor integration poses a number of problems, due to the presence of cables and on-board electronics. Passive, wireless SAW sensors offer a very promising solution, here. We used commercial SAW devices mounted on steel rebars to carry out an initial feasibility study. Without cables or embedded electronics, we were able to measure the deformation of a concrete beam subjected to bending load. We were also able to measure the temperature continuously over a three-week period.