Design and Error Correction of EIP Steel Bar Corrosion Monitoring Device

Abstract:

In order to study the problems of large errors and difficulty in quantification when using electromagnetic methods to detect steel corrosion, this paper developed a set of steel corrosion monitoring device based on the principle of electromagnetic induction by utilizing the difference in magnetic permea-bility between the steel bars and their corrosion products. This monitoring device uses permanent magnets to provide a closed magnetic field, transmits the magnetic field using silicon steel sheets, and embeds Hall elements at both ends of the silicon steel sheets to sense the changes in magnetic permeability caused by steel corrosion. Through calibration, a correction formula for the theoretical calculated corrosion rate of the internal steel bars in concrete and the actual corrosion rate was obtained based on Faraday’s formula. The maximum error between the corrosion amount of the steel bars calculated by this correction formula and the actual corrosion amount measured by the weight loss method was 1.044%. Through the concrete internal sensor test, an accurate relationship between the corrosion amount of the steel bars and the change in Hall voltage was obtained based on the linear regression model, providing a scientific method for the durability monitoring of reinforced concrete structures.