Long-term performance of distributed optical fiber sensors embedded in reinforced concrete beams under sustained deflection and cyclic loading
Journal article, 2021

This paper explores the performance of distributed optical fiber sensors based on Rayleigh backscattering for the monitoring of strains in reinforced concrete elements subjected to different types of long-term external loading. In particular, the reliability and accuracy of robust fiber optic cables with an inner steel tube and an external protective polymeric cladding were investigated through a series of laboratory experiments involving large-scale reinforced concrete beams subjected to either sustained deflection or cyclic loading for 96 days. The unmatched spatial resolution of the strain measurements provided by the sensors allows for a level of detail that leads to new insights in the understanding of the structural behavior of reinforced concrete specimens. Moreover, the accuracy and stability of the sensors enabled the monitoring of subtle strain variations, both in the short-term due to changes of the external load and in the long-term due to time-dependent effects such as creep. Moreover, a comparison with Digital Image Correlation measurements revealed that the strain measurements and the calculation of deflection and crack widths derived thereof remain accurate over time. Therefore, the study concluded that this type of fiber optic has great potential to be used in real long-term monitoring applications in reinforced concrete structures.

Performance indicators

Rayleigh backscattering

Distributed optical fiber sensing

Cyclic loading

Reinforced concrete


Ignasi Fernandez

Chalmers, Architecture and Civil Engineering, Structural Engineering

Carlos Gil Berrocal

Thomas Concrete Group

Chalmers, Architecture and Civil Engineering, Structural Engineering

Rasmus Rempling

Chalmers, Architecture and Civil Engineering, Structural Engineering



1424-8220 (ISSN) 1424-3210 (eISSN)

Vol. 21 19 6338

SensIT - Sensor driven cloud-based strategies for infrastructure management

Microsoft Research, 2018-07-01 -- 2020-08-31.

WSP Sverige, 2018-07-01 -- 2020-08-31.

NCC AB, 2018-07-01 -- 2020-08-31.

Thomas Concrete Group, 2018-07-01 -- 2020-08-31.

Swedish Transport Administration (2018/27871), 2018-07-01 -- 2020-08-31.

Subject Categories

Medical Laboratory and Measurements Technologies

Other Medical Engineering

Other Physics Topics





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