Experimental Study on Residual Bending Strength of Corroded Reinforced Concrete Beam Based on Micromagnetic Sensor

Abstract

This paper presents a nondestructive test method to evaluate the residual bending strength of corroded reinforced concrete beam by analyzing the self-magnetic flux leakage (SMFL) signals. The automatic scanning device was equipped with a micromagnetic sensor and sensor-based experimental details were introduced. Next, the theoretical formula of the normal component HS(z) of the SMFL signal that originated from the corroded region was derived based on the magnetic dipole model and the experimental results were discussed. The results indicate that the experimental data of HS(z) are consistent with the theoretical calculations, both location and extent of the steel bars corrosion can be qualitatively determined by using HS(z). The gradient K of HS(z) is approximately linearly related to the loss rate, S, of the bending strength, which can be used to evaluate the residual bending strength of the corroded reinforced concrete beam. This work lays the foundation for evaluating the residual bending strength of corroded reinforced concrete beams using the SMFL signal; the micromagnetic sensor is further applied to the civil engineering.

Grading Evaluation of Overall Corrosion Degree of Corroded RC Beams via SMFL Technique

“…Te results show that the efect of rebar diameter on the quantitative detection can be eliminated by describing the degree of corrosion and the average section loss ratio α [29]. Zhou et al evaluated the residual bending strength of the corroded reinforced concrete beams by analyzing the SMFL signal [30]. Qiu et al proposed a nondestructive quantifcation method of the local corrosion cross-sectional area of the reinforcement on the basis of the dynamic linkage mechanism of the induced magnetic feld and SMFL feld of the reinforcement [31].…”

Research on the magnetic flux leakage field distribution characteristics of defect in low-frequency electromagnetic detection technique

“…It is clear that the use of the unsaturated AC excitation method in LFET [8,9,10,11] inevitably results in a weakened LF-MFL field at defects in the surface of inspected materials. An inductive magnetic coil [12,13,14,15,16] (LFET coil) is typically used as a substitute for traditional magnetic sensitive component [17,18] to avoid disturbances from the external DC magnetic field, reflecting the tangential magnetic variation. Meanwhile, the highsensitivity magnetoresistive (MR) sensor is always adopted as the signal acquisition medium [19,20,21], although it is affected greatly by spatial magnetic field.…”

Investigation of Residual Bearing Capacity of Corroded Reinforced Concrete Short Columns under Impact Load Based on Nondestructive Testing

“…Zhang et al [8] proposed a nondestructive test method for steel corrosion in RC structures by using a 3-dimensional digital micromagnetic sensor to detect and analyze the selfmagnetic field leakage from corroded RC structures, which can be used to detect and evaluate the range of the inner steel corrosion in engineering structures. Based on the analysis of magnetic flux leakage signals, Zhou et al [9] proposed a nondestructive testing method that can qualitatively determine the location and extent of steel corrosion.…”