title: The performance analysis of distributed Brillouin corrosion sensors for steel reinforced concrete structures.
abstract: The Brillouin optical time-domain analysis (BOTDA)-based optical fiber method has been proposed to measure strain variations caused by corrosion expansion. Spatial resolutions of 1 m can be achieved with this kind of Brillouin sensor for detecting the distributed strain. However, when the sensing fiber is wound around the steel rebar in a number of circles in a range of several meters, this spatial resolution still has limitations for corrosion monitoring. Here, we employed a low-coherent fiber-optic strain sensor (LCFS) to survey the performance of Brillouin sensors based on the fact that the deformation measured by the LCFS equals the integral of the strains obtained from Brillouin sensors. An electrochemical accelerated corrosion experiment was carried out and the corrosion expansion was monitored by both BOTDA and the LCFS. Results demonstrated that the BOTDA can only measure the expansion strain of about 1,000 με, which was generated by the 18 mm steel rebar corrosion, but, the LCFS had high sensitivity from the beginning of corrosion to the destruction of the structure, and no obvious difference in expansion speed was observed during the acceleration stage of the corrosion developed in the reinforced concrete (RC) specimens. These results proved that the BOTDA method could only be employed to monitor the corrosion inside the structure in the early stage.
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. hmwei@mail.dlut.edu.cn.
authors.forename: Heming
authors.initials: H
authors.lastname: Wei
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. zhaoxf@dlut.edu.cn.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. kongxianglong@cgnpc.com.cn.
authors.forename: Xianglong
authors.initials: X
authors.lastname: Kong
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. zpl200421013@gmail.com.
authors.forename: Pinglei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. cuiyanjun863@163.com.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Cui
authors.affiliation: College of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024, China. suncs@dlut.edu.cn.
authors.forename: Changsen
authors.initials: C
authors.lastname: Sun