C-FRCM Jacket Confinement for RC Columns under Impressed Current Cathodic Protection

Abstract

In coastal regions, chloride penetration causes steel reinforcing bar (rebar) corrosion in reinforced concrete structures, leading to durability problems in existing structures. A new intervention method, impressed current cathodic protection and structural strengthening (ICCP-SS), was adopted to rehabilitate sea–sand concrete columns. A carbon fiber-reinforced cementitious matrix (C-FRCM) was used as a dual-functional material in the ICCP-SS system, wherein the C-FRCM served as both an anode and a strengthening material. This study aimed to consider the effects of the total charge density on the confinement effect of C-FRCM jackets and the compressive strength of columns under ICCP-SS intervention to demonstrate the long-term effectiveness of the ICCP-SS intervention method for sea–sand RC columns and to investigate the appropriateness of existing strength models for RC columns strengthened by C-FRCM jackets under impressed current cathodic protection (ICCP). The experimental program included a total of nine reinforced concrete stub columns. Prior to the compression tests, the columns were subjected to 270 days of accelerated corrosion and 250 days of cathodic protection under protective cathodic current densities of 20 and 60 mA/m2. This paper presented an experimental program, a comparison between short-term and long-term test results of ICCP-SS, a comparison of existing strength models, and a discussion on the appropriateness of the existing models for C-FRCM jackets subjected to an applied current.