Assessment of the stress corrosion cracking in a chloride medium of cables used in prestressed concrete structures by the acoustic emission technique

Abstract

In this paper, two main types of corrosion, localized corrosion and stress corrosion cracking (SCC) of cables used in prestressed concrete structures, were characterized and identified by acoustic emission (AE) analysis using extracted AE parameters. A novel analysis of the AE parameters using the principal component analysis (PCA) was done to discriminate localized corrosion from SCC. First, K-mean was used as an unsupervised method, and then to validate the clustering analysis k-nearest neighbour was used as a supervised method. The correlations of the AE parameters including amplitude, counts, hits and time were also used to identify corrosion mechanisms. In addition, the corrosion process characteristics of each type were explained by applying the AE signal analysis (time-frequency). Experimental results show the ability of AE to evaluate a crack propagation rate of 10 −7 m s −1 in a chloride medium. Microscopic examinations revealed a mixed mode of crack propagation, modes I (shear-like mechanism) and II (cleavage-like mechanism), characterized by a multi-terrace appearance on the fractured steel surface.

Performance of 45-year-old corroded prestressed concrete beams

“…Close examination showed, however, that one wire had fractured along the length of the wire (inset, Figure 14). This is very unusual for steel stressed in tension, but is similar to the usual failure mode for steel subject to SCC or HE (Ramadan et al, 2008). Similar longitudinal cracks were found in wires in beam B.…”

Development and Validation of Quantitative Model-Based Image Reconstruction for NDE of Reinforced Steel-Lined Concrete Structures: Kal-El FY 2020

“…Consequently, the problem of rebar corrosion detection in reinforced concrete has seen a significant amount of research. Conventional NDE inspection solutions that have been proposed include acoustic emission Ramadan et al (2008), capacitance-based measurements Cheng et al (2018), eddy current de Alcantara Jr. et al (2016), microwaves and GPR Pieper et al (2014), ultrasonics (measuring linear or non-linear response, or using ultrasonic guided waves) Beard et al (2003); Yeih and Huang (1998); Watanabe et al (2014); Sriramadasu et al (2019); Singh et al (2019).…”

Examination Technologies

“…This method is based on the assumption that different sources of AE will exhibit unique b-coefficient values. Methods to automatically cluster and classify signals include K-means (Ramadan et al 2008;Shaira et al 2008) principle component analysis (Ramadan et al 2008), and neural networks (Barga et al 1990).…”

“…Nonlinear guided waves have been investigated as means to inspect prestressing tendons in bridges (Bartoli et al 2009) and cylindrical guided waves have been investigated to detect delamination between corrugated reinforcing steel rods and the embedding concrete member (Miller 2010). AE has been investigated as a tool to detect corrosion in both reinforcing steel (Zdunek et al 1995) and prestressing tendons (Ramadan et al 2008).…”

“…The use of wideband transducers would result in less signal distortion and may improve the ability to discriminate AE signals of interest from extraneous signals-at the expense of reduced sensitivity. Principal component analysis (PCA) has been investigated as a technique to distinguish AE signals (Ramadan et al 2008;Shaira et al 2008). The development and application of PCA and other sophisticated algorithms for AE signal analysis may reduce the susceptibility of AE to extraneous sources of signals and aid in characterization of the degradation mechanism.…”