In situ monitoring of prestressed concrete using embedded fiber loop ringdown strain sensor

In situ monitoring of prestressed concrete using embedded fiber loop ringdown strain sensor

Fiber loop ringdown

Fiber optic sensor

Prestressed concrete

Strain sensor

Structural health monitoring

We report near real-time in situ monitoring of prestressed concrete beams using a new fiber loop ringdown (FLRD) strain sensor. The strain sensor was fabricated by integrating a micro air-gap in the sensor head and had a strain detection limit of tens of nanostrain (nε). Two unbonded prestressed concrete beams were constructed with two strain sensors embedded in each concrete beam

one sensor was attached to the post-tensioned (PT) rod, while the second sensor was embedded in the concrete beam. A tensioning stress of up to 351 MPa was produced on the PT rod in steps of 39 MPa, and during a three-point loading test of the concrete beams, a force of up to 8 kN was applied in steps of 1 kN. Results demonstrated the ability of the FLRD strain sensor for sensing the stress on the PT rod as well as on the concrete far before the crack initiation.

224-232

124

Ghimire, Maheshwar

Wang, Chuji

Dixon, Kenneth

Serrato, Michael

Measurement

2018

journalArticle

0263-2241

10.1016/j.measurement.2018.04.017