Electromagnetic field principle-based external nondestructive steel bar corrosion monitoring sensor and testing method

Abstract

The invention discloses an electromagnetic field principle-based steel bar corrosion monitoring sensor, which comprises a magnetic induction intensity monitoring unit and a data processing unit, wherein the magnetic induction intensity monitoring unit comprises a magnetic core, a coil, a packaging housing, hall sensors and a signal generator; and the data processing unit comprises a signal processor and a central processor. The invention further provides a testing method for the electromagnetic field principle-based steel bar corrosion monitoring sensor. The method comprises the steps of pretreating a to-be-tested specimen; measuring the magnetic induction intensity; carrying out calibration test; and calculating the steel bar corrosion rate according to a calibration fitting equation. According to the electromagnetic field principle-based steel bar corrosion monitoring sensor and the testing method, the defect of corrosion monitoring of steel bars built in concrete in a traditional testing method is overcome, the effects of changes in steel bar positions and bayonet sizes on steel bar corrosion monitoring are removed through symmetrically arranging the hall sensors and controllingthe electromagnetic field intensity, accurate monitoring of reinforced concrete corrosion is achieved, and the electromagnetic field principle-based steel bar corrosion monitoring sensor and the testing method are suitable for a mortar specimen and also suitable for a concrete specimen.

Description

technical field [0001] The invention relates to steel bar corrosion monitoring technology in construction engineering, in particular to an external non-destructive monitoring sensor and testing method for steel bar corrosion based on the principle of electromagnetic field. Background technique [0002] Reinforced concrete structure combines the tensile strength of steel bars and the compression resistance of concrete. Since it was applied in the field of civil engineering in the mid-19th century, it has become the most widely used structure in the world due to its low cost, wide selection of materials, and convenient construction. structure type. For a long time, the damage caused by the durability failure of concrete has been huge, which has far exceeded people's expectations and has become a worldwide problem. Among the causes of concrete durability failure, steel bar corrosion is the most serious, which has attracted widespread attention at home and abroad. In view of t...

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Problems solved by technology

The half-cell potential method uses the electrochemical reaction of steel corrosion to cause potential changes to measure the corrosion state of steel bars, but its accuracy is low, and it can only qualitatively judge the corrosion probability of steel bars, and there is no unified judgment standard; acoustic emission technology is based on parameters such as the cumulative number of impacts , can only determine the probability of corrosion qualitatively, and cannot quantitatively measure the corrosion rate of steel bars; the method for monitoring steel bar corrosion based on the principle of magnetic field, the Chinese patent authorization announcement number CN109374726A, the date of authorization announcement is February 22, 2019, and the name is "Concrete China Steel Corrosion Non-destructive Dynamic Monitoring Sensor and System" and China Patent Authorization Announcement No. CN208420791U, the authorized announcement date is January 22, 2019, and the name is "An Electromagnetic Field Variable Response Device for Steel Corrosion". The two patents provide a built-in The steel bar corrosion monitoring sensor based on concrete is used to monitor the corrosion of steel bars built into concrete, but the built-in monitoring sensor will seriously affect the mechanical properties of reinforced concrete and the natural corrosion law of steel bars, and such sensors can only be built into concrete once. The cost is relatively high; the Chinese Patent Authorization Announcement No. CN108469514A, the authorized announcement date is August 31, 2018, and the name is "a monitoring device and method for the corrosion behavior of steel bars in concrete". The sensors involved in this patent still exist Deficiencies: First, although the sensor can measure the corrosion of steel bars, it can only qualitatively judge the overall corrosion of steel bars in concrete, and cannot judge the corrosion of a single steel bar. However, the corrosion of steel bars in concrete is different in actual engineering, so it is necessary to The corrosion situation of a single steel bar is measured; the 2nd, prove through the test result of the inventor, the influence of the position of the steel bar is far greater than the influence of the corrosion of the steel bar on the Hall sensor response situation, it can be seen that the steel bar cannot guarantee that the error is larger under the situation of in-situ monitoring The third is that the patented Hall sensor is only arranged in a single linear direction, and this method cannot effectively monitor the change of the position of the steel bar. The bayonet of the magnetic core is relatively large, and the test result of the inventor proves that the increase of the bayonet will cause the detection sensitivity of the Hall sensor to decrease

In summary, the measurement results of the sensors involved in this patent cannot reflect the real corrosion of steel bars, and accurate and reliable data cannot be obtained to predict the corrosion degree of steel bars in different situations

[0004] In actual construction projects, there is still no external dynamic monitoring sensor and test method for accurately measuring the corrosion rate of steel bars

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