Study on the potential change of corroded reinforced concrete in ECE with MPC-CFRP as anode

Yue Li,Xiuhu Zhang,S.M.Ali S Hejazi,O.S Es-Said,P Jisheng

doi:10.1051/matecconf/202031906005

Yue Li, Xiuhu Zhang + Show 3 more

Open Access

https://doi.org/10.1051/matecconf/202031906005

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Abstract

Aiming at the rust removal requirements of reinforced concrete, the MPC-CFRP composite material was used as the external anode, and the Electrochemical chloride extraction (ECE) method was used to test the polarization curve of the steel bar under different ECE current densities, and the potential changes of the steel bar at different times were analyzed. The results show that the ECE system with MPC-CFRP as the external anode has a good effect of reducing the corrosion rate and the risk of corrosion of steel bars. The current density of 3A/m2is higher than that of 1A/m2in dechlorination efficiency. After 28 days of ECE, the current density of 1A/m2and 3A/m2can re passivate the reinforcement.

Highlights

In this paper, magnesium phosphate cement (MPC) is used as the binder to bond CFRP on the surface of Corrosion of steel bars is the main reason that affects the durability of reinforced concrete structures [1]
Before Electrochemical chloride extraction (ECE), the reinforced concrete column was electrified for 24 days by constant current method to accelerate the corrosion of steel bars; MPC was painted on the surface of corroded reinforced concrete column and CFRP was pasted as the anode of ECE and the column longitudinal bar as the cathode
With MPC as binder, CFRP was bonded on the surface of reinforced concrete to form MPC-CFRP composite as the external anode of ECE

Summary

Introduction

Magnesium phosphate cement (MPC) is used as the binder to bond CFRP on the surface of Corrosion of steel bars is the main reason that affects the durability of reinforced concrete structures [1]. ECE can effectively inhibit the corrosion of steel bars and improve the durability of corroded reinforced concrete structures [5]. Carmona et al studied the effect of ECE of different anodes, and pointed out that for the isotropic structural elements, the effect of corroded reinforced concrete, forming MPC-CFRP composite as the external anode of ECE. In order to accelerate the corrosion of reinforcement, the concrete is mixed with 3% sodium chloride of cement mass fraction to discuss the effect of ECE. The thickness of CFRP is 0.19 mm, the ultimate tensile strength and fracture strain are 4200 Mpa and 2%, respectively

RC component manufacturing

ECE test design and method

Polarization curve analysis of reinforced concrete specimens

Conclusions