Anodic and Mechanical Behavior of Carbon Fiber Reinforced Polymer as a Dual-Functional Material in Chloride-Contaminated Concrete.

Ji-Hua Zhu,Wei Liu,Meini Su,Zhijun Dong,Feng Xing,Jun Liu,Liangliang Wei

doi:10.3390/ma13010222

Abstract

Carbon fiber reinforced polymer (CFRP) has been used as a dual-functional material in a hybrid intervention system (ICCP-SS) which integrates the impressed current cathodic protection (ICCP) and structural strengthening (SS). The mechanical behavior of CFRP as an anode has been investigated in some solution environments. However, the anodic and mechanical behavior of CFRP bonded to concrete is unclear. This paper focuses on the anodic and mechanical performance of CFRP bonded to the chloride-contaminated concrete by conducting an electrochemical (EC) test. The method of bonding the CFRP to the concrete and the shape of the steel embedded in the concrete were considered. The current densities of 20 mA/m2 and 100 mA/m2 were applied during 120-day and 310-day EC tests. The electrode potentials and driving voltages were recorded, and the bond interfaces of the CFRP were inspected after EC test. The residual tensile strength and failure modes of the CFRP were analyzed after tensile tests. Finally, the long-term performance of CFRP as a dual-functional material in ICCP-SS system was discussed. Results show that the externally bonding CFRP in ICCP-SS system can not only protect the steel in chloride-contaminated concrete effectively but also maintain 70% of the original tensile strength of CFRP at a charge density of 744 A·h/m2. The expected service period of CFRP as a dual-functional material bonded to the chloride-contaminated concrete was determined to be more than 42.5 years.

Highlights

In recent years, a new intervention system, integrating impressed current cathodic protection (ICCP) with structural strengthening (SS), has been proposed to be ICCP-SS for improving the maintenance of concrete suffered from the corrosion of steels induced by chloride [1,2,3,4]
The results show that RF1 and RF2, which were chloridewithout EC tests, still suffered a relatively high corrosion level, while the corrosion probability of the contaminated concrete specimens without EC tests, still suffered a relatively high corrosion level, steel rebars and steel plate in the chloride-contaminated concrete was reduced significantly due to the while the corrosion probability of the steel rebars and steel plate in the chloride-contaminated protection of the ICCP system
The anodic and mechanical behavior of carbon fiber reinforced polymer (CFRP) as a dual-functional material in chloridecontaminated concrete was assessed and discussed through the EC tests followed by the tensile tests

Summary

Introduction

A new intervention system, integrating impressed current cathodic protection (ICCP) with structural strengthening (SS), has been proposed to be ICCP-SS for improving the maintenance of concrete suffered from the corrosion of steels induced by chloride [1,2,3,4]. It is well known that impressed current cathodic protection can effectively mitigate the corrosion of steel by utilizing an electrochemical mechanism [6]. Zhu et al [1] and Su et al [3] found that the ICCP-SS system could work effectively in protecting the steel reinforcement and increasing the ultimate strength of concrete columns and beams contaminated by chloride. The anodic and mechanical behavior of CFRP suffered from polarization in ICCP was not clarified and requires further investigation

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