Optical fiber concrete freezing-thawing expansion strain monitoring sensor

Abstract

An optical fiber concrete freezing-thawing expansion strain monitoring sensor comprises a single mode anti-bending optical fiber winding coil, a temperature compensation optical fiber grating, a concrete cylinder which is 5cm-8cm in diameter, a cement mortar protective layer, a steel pipe and an optical cable. The concrete cylinder is manufactured by concrete which has a same ratio as measured concrete materials, and the optical fiber winding coil is used for directly measuring circumferential deformation of the concrete cylinder caused by freezing-thawing. Circumferential deformation of the concrete cylinder in a whole measuring point can be monitored from a service period to the whole process that the protective layer is cracked and stripped after the interaction process of a plurality of freezing-thawing circulating periods is undergone, so that concrete freezing-thawing expansion strain is accurately monitored. An optical fiber sensor technology is adopted, so that durability of the sensor is greatly improved. The sensor manufactured through a packaging method is suitable for freezing-thawing expansion strain monitoring of bridges, dams and other concrete structures, and the optical fiber concrete freezing-thawing expansion strain monitoring sensor has the advantages of being simple in process, convenient to arrange, high in accuracy, long in service life and the like.

Description

technical field [0001] The invention belongs to the technical field of structural engineering safety monitoring and optical fiber sensing, and relates to a novel optical fiber concrete freeze-thaw expansion strain monitoring sensor. Background technique [0002] Optical fiber sensing technology is an ideal sensing element for long-term safety monitoring of civil engineering structures. It has high resolution, high precision, small size, good durability, anti-electromagnetic interference, and can perform long-distance quasi-distributed / distributed real-time It has the advantages of monitoring and other advantages, so it has broad application prospects in the sensing technology of structural health monitoring, especially in the occasion of measuring stress and strain, it has the advantages that some other sensors cannot match, and is considered to be the most promising integration in the material. , a sensor that detects its damage. [0003] The freeze-thaw damage of reinforc...

AI Technical Summary

Problems solved by technology

This method uses a corrosion-resistant metal rod as a probe, and the application of metal materials will inevitably introduce the problem of sensor durability.

In addition, the sensor mainly realizes the monitoring of concrete freeze-thaw peeling through the probe array, but it is difficult to measure the freeze-thaw expansion damage inside the concrete before peeling off.

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