Review of Physical Based Monitoring Techniques for Condition Assessment of Corrosion in Reinforced Concrete

Ying Lei,Zhu-Peng Zheng

doi:10.1155/2013/953930

Abstract

Monitoring the condition of steel corrosion in reinforced concrete (RC) is imperative for structural durability. In the past decades, many electrochemistry based techniques have been developed for monitoring steel corrosion. However, these electrochemistry techniques can only assess steel corrosion through monitoring the surrounding concrete medium. As alternative tools, some physical based techniques have been proposed for accurate condition assessment of steel corrosion through direct measurements on embedded steels. In this paper, some physical based monitoring techniques developed in the last decade for condition assessment of steel corrosion in RC are reviewed. In particular, techniques based on ultrasonic guided wave (UGW) and Fiber Bragg grating (FBG) are emphasized. UGW based technique is first reviewed, including important characters of UGW, corrosion monitoring mechanism and feature extraction, monitoring corrosion induced deboning, pitting, interface roughness, and influence factors. Subsequently, FBG for monitoring corrosion in RC is reviewed. The studies and application of the FBG based corrosion sensor developed by the authors are presented. Other physical techniques for monitoring corrosion in RC are also introduced. Finally, the challenges and future trends in the development of physical based monitoring techniques for condition assessment of steel corrosion in RC are put forward.

Highlights

Reinforced concrete (RC) makes up a large part of the civil infrastructures
The reinforcement is corroded within the concrete structure, the resulting species deposits continuously on the surface of the rebar because the loss of mass is hindered by concrete, the volume of the steel rebar increases during corrosion, and the coverage concrete is cracked
Resistance probes made of the same material with steel bar are first embedded in concrete, and the resistance of probes can be measured by balancing bridge which is inversely proportional to its cross-sectional area

Summary

Introduction

Reinforced concrete (RC) makes up a large part of the civil infrastructures. For instance, over half of the building and bridge inventories in China are reinforced concrete. It is imperative to develop effective monitoring techniques for condition assessment of corrosion in reinforced concrete. There are still many challenges and difficulties of these physical based monitoring techniques for practical application of condition assessment of corrosion in reinforced concrete because the reinforcements are typically embedded inside concrete. This paper reviews some physical based monitoring techniques with emphases on the UGW and FBG based monitoring techniques for the condition assessment of steel corrosion in reinforced concrete in the last decade. The challenges and future trends in the development of physical based monitoring techniques for condition assessment of corrosion in reinforced concrete are put forward. The challenges and future trends in the development of physical based monitoring techniques for condition assessment of corrosion in reinforced concrete are summarized in the conclusions

UGW Based Techniques for Corrosion Monitoring of RC

Introduction of Some Other Physical Techniques for Monitoring Corrosion in RC

Findings

Conclusions