EIP钢筋锈蚀量监测装置的设计与误差校正

Design and Error Correction of EIP Steel Bar Corrosion Monitoring Device

摘要:

为了研究电磁法在检测钢筋锈蚀时存在的误差大、难定量问题,通过钢筋与其锈蚀产物间的磁导率差异,基于电磁感应原理开发了一套钢筋锈蚀量监测装置。该监测装置采用永磁体来提供闭合磁场,用硅钢片传输磁场,同时在硅钢片两端镶嵌霍尔元件来感应钢筋锈蚀产生的磁导率变化。通过标定,基于法拉第公式得出了混凝土内部钢筋理论计算锈蚀率与实际锈蚀率间的修正公式,通过该修正公式计算得到的钢筋锈蚀量与通过失重法实测的钢筋锈蚀量数值间的最大误差为1.044%。通过混凝土内埋传感器试验,基于线性回归模型得到了钢筋锈蚀量与霍尔电压变化量之间的精确关系,为钢筋混凝土结构耐久性监测提供了科学方法。

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.