Monitoring Corrosion of Steel Bar in Concrete Using Ultrasonic Wave

Abstract

The problem of steel corrosion in reinforced concrete structure is very serious. The purpose of this paper is to monitor steel corrosion by ultrasonic guided wave. Ultrasonic guided wave monitoring is a kind of dynamic nondestructive testing technology, which has the advantages of real-time, on-line and continuous. In this paper, an ultrasonic in-situ monitoring technique of steel bar corrosion based on embedded piezoelectric ceramic sensor is introduced. Based on this, ultrasonic guided wave was used to monitor mortar samples with different strengths of uniform corrosion, and scanning electron microscopy was used to observe the interface between reinforcement and concrete at different corrosion stages. The results show that the variation trend of ultrasonic guided wave amplitude can reflect the degree of corrosion. Mortar with different strength will affect the time and trend of corrosion. The scanning electron microscopy (SEM) method shows that the changing process of the interface between reinforcement and concrete is consistent with the trend of ultrasonic guided wave.