Monitoring fracture of steel corroded reinforced concrete members under flexure by acoustic emission technique

Abstract

Acoustic emission (AE) technique is used for monitoring and evaluating the influence of corrosion on the structural behaviour of steel reinforced concrete (RC) beams under three-point flexure test. In this study, steel corrosion was accelerated by electro-chemical method utilising a direct current (DC) power supply and 5% sodium chloride (NaCl) solution. The steel corrosion that was induced into beam specimens casting were estimated at 0%, 4.55% and 32.37%, respectively, according to mass loss of steel reinforcement. Based on observations during static load test, the damage developed in the specimens could be classified into four different stages, namely, micro-cracking, first visible cracks, cracks distribution, as well as damage localization and yielding. Analysis of the AE data reveals distinguishable trends for RA value and average frequency (AF) registered for different corrosion levels, respectively. Moreover, the index of damage (ID) derived from the AE energy parameters obtained during the first stage of damage was found to be useful as an indicator for evaluating the extent of corrosion damage of RC beam specimens at initial loadings. In addition, to provide a practical application of AE toward life span estimation of corroded beam specimen, a Weibull damage function was introduced to estimate the remaining flexural capacity of the beam specimens. Based on analysis as well, it is noted that tensile fracture became more dominant with an increase in corrosion level.

In-Situ Monitoring and Analysis of the Pitting Corrosion of Carbon Steel by Acoustic Emission

“…As one of the most destructive forms of localized corrosion, pitting corrosion of carbon steel intensively occurs in many sites, such as steel in reinforced concrete, and steel with degraded coatings of a bridge or water containment structure. Many investigations [1][2][3] have been done for the detection of structural failure of concrete with the acoustic emission (AE) technique. As the initiation stage of many structural degradation cases, the pitting corrosion of carbon steel needs to be monitored.…”

“…Many techniques have been used to study pitting corrosion. The American Society for Testing and Materials (ASTM) has standardized methods for the study/evaluation of pitting corrosion and pitting tests in 6% FeCl 3 . Electrochemical measurements are most commonly used in investigating pitting corrosion behavior, e.g., polarization curves measuring the break potential of pitting, E b ; protective potential of pitting, E p ; and the free corrosion potential, E corr .…”

Determination of yielding point by means a probabilistic method on acoustic emission signals for application to health monitoring of reinforced concrete structures

“…By using a proper array of sensors mounted on the RC structure, it is theoretically possible to determine the location of the AE source by analyzing the arrival times of the waves to each sensor . Similarly, AE testing can be used to study the initiation and growth of cracks in concrete in real time …”

“…3,4 Similarly, AE testing can be used to study the initiation and growth of cracks in concrete in real time. [5][6][7][8][9][10] It is known that "damage" is physical harm that impairs the value, usefulness, or normal function of something. Over the past few years, researchers have attempted to study the state of damage in RC structures using parameterbased AE monitoring techniques.…”

Characteristic of Acoustic Emission Signal from Stress Corrosion Cracking in Low-Carbon Nitrogen-Enhanced Stainless Steel

“…(16,(19)(20)(21) Many research results show that there is a very close relationship between AE phenomena and material fracture. (22)(23)(24)(25)(26)(27) Therefore, AE monitoring has the potential to achieve remote real-time monitoring of the initiation and propagation of SCC. AE phenomena refers to elastic wave phenomena in materials and structures produced by stress or fracture due to the rapid release of energy.…”