Monitoring Structural Performances of Concrete Beams Using Fibre Bragg Grating (FBG) Sensors

Monitoring Structural Performances of Concrete Beams Using Fibre Bragg Grating (FBG) Sensors

Structural health monitoring (SHM) of new and ageing civil infrastructures is becoming an essential process due to reduced maintenance costs and to avoid catastrophic failures. In particular concrete structures which are being exposed to harsh environments lose their useful operational lives due to many accumulated damages. As such, understanding of internal structural status of concrete structures is a critically essential requirement for their undisturbed and safe operational condition. In this study, a concrete beam with embedded Fibre Bragg Grating (FBG) sensors has been investigated under flexural loading for monitoring structural integrity. A concrete enclosure was designed and produced to enclose FBG sensor and embed it inside the beam during the casting. Therefore, it is expected to achieve uniform strain transfer between the FBG sensor and the surrounding concrete without reducing the structural integrity. The responses of the sensors were acquired from the pouring stage to the end of the curing stage and the cured beam was loaded on three-point bending arrangement. The beam was loaded up to 20 kN and the FBG sensor response was acquired during the loading. The experimental data gathered from the FBG were critically analysed. Further, a finite element model for the concrete beam was developed on commercial FEA software ABAQUS and the results was compared with the experimental results. The correlated FEA mesh can be used for prediction of structural performances under various conditions.