Study on seismic behavior of reinforced concrete columns after ECE treatment

• Bond behavior between steel reinforcing bars and concrete after ECE treatment is studied.
• Seven reinforced concrete circular columns treated with ECE under cycle loading are tested.
• The influence of bond deterioration on the seismic behavior of reinforced concrete columns is investigated.
• The seismic performance of RC columns treated with ECE process tends to deteriorate due to the bond degradation.

Electrochemical chloride extraction (ECE) is an important methodology used to mitigate corrosion of steel reinforcing bar by removing chlorides from concrete structures. However, during this process, the accumulation of positive ions (i.e. sodium ions, potassium ions, etc.) at the surface of the steel reinforcing bars can soften the surrounding concrete and impair the bond performance between the steel reinforcing bars and concrete, which may affect the seismic behavior of treated reinforced concrete members. In this paper, the effect of ECE on bond behavior between steel reinforcing bars and concrete is studied using bond tests of beam specimens; and the seismic performance of reinforced concrete columns treated with ECE is investigated using pseudo-static cyclic tests. Test results indicate that the bond strength between steel reinforcing bars and concrete decreases after ECE treatment, and as a result, the stiffness, ductility and energy dissipation capacity of treated columns under cycle reversed loading degrade.