Monitoring device and method for rust expansion and cracking of reinforced concrete based on optical fiber sensing

Abstract

The invention discloses a device and a method for monitoring corrosion-induced cracking of reinforced concrete based on optical fiber sensing. The device comprises a Brillouin optical fiber (1). The Brillouin optical fiber (1) comprises a plurality of strain monitoring optical fiber sections (3), each strain monitoring optical fiber section (3) is wound around a reinforced bar (8) in the center of a reinforced concrete structure by one circle, and all the strain monitoring optical fiber sections (3) are concentric. The length of the most inner circle of strain monitoring optical fiber section (3) is equal to the length of one spatial resolution dz, and from inside to outside, the length of each circle of strain monitoring optical fiber section (3) is one spatial resolution dz larger than that of the more inner circle of strain monitoring optical fiber section (3). The key of the method is that the width of a crack is worked out by multiplying the strain value of the strain monitoring optical fiber sections (3) by the spatial resolution dz. By adopting the device and the method, the width of a crack and the degree of extension of the crack from the center of the section of the concrete structure to the edge can be monitored.

Description

technical field [0001] The invention relates to the field of civil engineering health monitoring, in particular to a full-scale monitoring device and method for cracks of reinforced concrete rust swelling and cracking based on optical fiber sensing. Background technique [0002] Corrosion of steel bars is one of the main reasons for the durability failure of concrete structures. It is estimated that the annual maintenance and reinforcement costs of concrete structures worldwide due to steel bar corrosion reach 100 billion US dollars. Because with the occurrence and development of steel corrosion, the service performance and safety performance of reinforced concrete structures will be adversely affected. According to the mechanical model of reinforced concrete rust swelling and cracking, it can be known that the process of filling the pores of concrete with corrosion products during the process of steel corrosion will cause the increase of concrete strain, which will lead to ...

AI Technical Summary

Problems solved by technology

[0009] The monitoring device and detection method for rust expansion and cracking of reinforced concrete based on optical fiber sensing in the prior art have the following disadvantages: the device and method can only monitor the total strain on the concrete structure section, and the rust expansion crack always starts from the section The center of the concrete beam extends to the edge until the crack is completely penetrated from the center to the edge, that is, it is completely cracked, and the completely cracked crack appears in a specific position of the concrete beam, such as the side of the beam, which does not constitute a harmful crack, but appears on the bottom of the beam. It is a harmful crack But the device and method of prior art can not detect the specific position of the crack of this section, can't judge whether it is a harmful crack naturally, also can't detect the width of the crack and the degree that the crack extends from the center to the edge, naturally can't correct the concrete The whole process of rust swelling and cracking is tracked and monitored, and it is impossible to predict when the cracks will completely crack, so it is even more impossible to take targeted prevention and control measures for harmful cracks

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