engleski

Corrosion monitoring in concrete structures with fiber optics

Corrosion of steel reinforcement in concrete is major factor which provokes deterioration of concrete structures, reducing their service life. Maintenance and planning of the restoration work on reinforced concrete structures needs effective monitoring techniques, which must be accurate, cost effective, immune to aggressive influences, must provide long-time measurement stability. Corrosion of steel can be measured directly or indirectly by measuring parameters correlated with corrosion such as humidity, pH value, Cl- ion content, cracking in concrete due to corrosion process. There are many, mostly electrochemical monitoring techniques developed for this purpose. Chemical fiber optical sensors (FOS) are interesting approach for measurement of given parameters. FOS are advantageous compared with conventional measuring methods. They have long time stability, immunity to electromagnetic fields, ability for distributed measurements. FOS are in use for chemical analysis of solutions or gases, but their application for measurements in concrete structures need further research and development. FOS can be extrinsic or intrinsic. Extrinsic sensors use optical fiber for light guiding to the sensitive element and back to the detector. Intrinsic sensors use properties of fiber to measure given parameter. Some of many principles at which FOS can be based are evanescent wave absorption phenomenon and micro bending.

corrosion monitoring ; concrete ; fiber optics

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