Detection of Defects in Reinforced Concrete Structures Using Ultrasonic Nondestructive Evaluation with Piezoceramic Transducers and the Time Reversal Method.

Guoqi Zhao,Lu Zhang,Ben Wang,Di Zhang

doi:10.3390/s18124176

Abstract

Reinforced concrete is of vital importance in many civil and industrial structural applications. The effective bonding between steel and concrete is the core guarantee of the safe operation of the structures. Corrosion or other interface debonding in steel-concrete is a typical failure mode during the long service period of the structures, which can severely reduce the load-bearing capacity. The Non-destructive Evaluation technique has been applied to civil engineering structures in recent years. This paper investigates the evaluation of reinforced concrete structures that have interface defects, including the cross-sectional loss and cracks, by using the piezoceramic induced ultrasonic wave and time reversal method. Ultrasonic wave is used as actuating wave to obtain the signals with defect information. Time reversal method is applied to localize and characterize defect along the interface of the steel-concrete and to image the defect through the cross-sectional scanning. Experiments were conducted to perform Nondestructive Evaluation by using six reinforced concrete components with different levels of defects. The invisible damages were made by the cutting part of the steel and embedding a table tennis ball inside concrete structures. The results show that the time reversed method can locate and evaluate the defects along the steel reinforced concrete, and the obtained defect images at the cross-section of the concrete structure are accurate.

Highlights

Concrete is the most widely used construction material in civil engineering due to its long service life and durability in harsh environments [1]
Monitoring reinforced concrete structures with ultrasonic waves based on time reversed method location, which shows that the time reversed method can identify the two defects inside concrete both from the steel ends and the concrete surface can evaluate the defect severity and can identify the structures
Detecting samples, the incident waves are carefully selected by the material parameters and the geometry of the samples

Summary

Introduction

Concrete is the most widely used construction material in civil engineering due to its long service life and durability in harsh environments [1]. This material has an excellent mechanical and structural performance when working with steel reinforced concrete during its service life. It has important issues in terms of durability when the concrete structures are exposed to corrosive environments and harsh conditions. Corrosion-induced cracking in pre-stressed concrete elements has been one of the most dominant factors that cause the deterioration of concrete structures. Corrosion is a major safety and economic concern for various industries [3,4]

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