The Application Of Fiber-optic White-light Strain Sensor For Corrosion Monitoring In The Reinforced Concrete Structure

The problem of corrosion of reinforced concrete structure (RCS) affect of national economic development and people’s lives. In recent years, the corrosion of RCS caused the bridge collapse, the buildings collapsed in the world have repeatedly occurred. The corrosion monitoring of the RCS has become a worldwide hot topic in both academic and engineering. However, until now still lack of an effective method to solve this problem.In this paper, a new method for corrosion monitoring in the RCS is proposed. This method is based on the fiber-optic white-light (FOW) Michelson interferometer principle. Measurement of steel corrosion caused by the deformation can be used to evaluate the progress of the corrosion in RCS. In the experiment, sensors affixed to the cushion reinforced surface, and then cushion reinforcement into the mortar made of test block. Accelerated corrosion test block was carried out by electrochemical method. Monitoring the corrosion process of the RCS block and drawing the Record Deformation-Time curve demonstrated the effectiveness of the proposed method.Compared the measured Deformation-time curve from the FOW sensor with those from the Fiber Bragg Grating(FBG) and the Brillioin-scattering Optical Time Domain Reflector (BOTDR), the following conclusions can be concluded:A) The FOW method is more sensitive than the FBG method and, then, it can monitor corrosion in RCS in the earlier stage.B) Compared with the BOTDR method, the results from the FOW is more smooth and better linear correlation.The experiment results proved that the FOW deformation sensors used to monitoring the corrosion of the RCS is feasible.