Nondestructive quantitative estimation of cross-sectional corrosion degree of rebar using self-magnetic flux leakage field variation

TL;DR

This paper presents a non-destructive magnetic flux leakage method to accurately quantify the corrosion degree of rebar in concrete structures, enabling rapid and precise structural assessments.

Contribution

It introduces a novel quantitative index NHx and a Bayesian model to automatically estimate rebar corrosion degree from magnetic flux leakage data.

Findings

Self-magnetic flux leakage accurately identifies corrosion range with error under 3%.

The NHx index correlates linearly with corrosion degree and fits Weibull distribution.

The method is practical, efficient, and suitable for engineering applications.

Abstract

To accurately assess the structural performance of corroded reinforced concrete structures, obtaining precise information on the corrosion range and corrosion degree of rebar is crucial. In this study, based on a comprehensive analysis of extensive high-precision magnetic field and three-dimensional structural light scanning data of 21 corroded rebars, it was found that the self-magnetic flux leakage can accurately identify the corrosion range, with an error not exceeding 3%. A proposed quantitative index NHx of the self-magnetic flux leakage amplitude exhibits a linear correlation with the cross-sectional corrosion degree of rebar, whose probability density distribution can be accurately described using the Weibull distribution function. Utilizing the Weibull distribution function of NHx and a Bayesian model, automatically rapid quantification of the rebar's cross-sectional corrosion degree based on the non-destructive testing-derived NHx values can be conveniently realized. This self-magnetic flux leakage-based novel method for quantifying rebar's cross-sectional corrosion degree is accurate, efficient, and well-suited for practical engineering applications, providing robust support for a precise assessment of the structural performance of corroded reinforced concrete structures.