Abstract
Electrodeposition has been proposed as a method to promote mineral precipitation in cracked
reinforced concrete, potentially limiting ingress of aggressive agents and delaying corrosion initiation.
However, the extent to which electrodeposition-induced crack filling improves corrosion resistance
under marine exposure, and the influence of electrolyte composition on the effectiveness and
mechanism of electrodeposition, remains overlooked.
This study investigated deposition behaviour of electrodeposition in either artificial seawater or Ca
Mg nitrate solution and evaluated corrosion performance of electrodeposition-treated (2x3) and non
electrodeposition-treated (references, 2x2) specimens during artificial seawater exposure.
Reinforced concrete cylinders containing tensile-induced transverse cracks underwent three-month
electrodeposition treatment, followed by a three-month artificial seawater exposure. Crack filling and
deposition patterns were examined using X-ray computed tomography (XCT), optical microscopy, and
µXRF elemental mapping, while corrosion behaviour was assessed through half-cell potential
monitoring and post-exposure CT. Analytical interpretation was further used to interpret observed
electrodeposition behaviour.
A difference in Ca²⁺ and Mg²⁺ ion concentrations between the Ca-Mg nitrate solution and artificial
seawater results in different crack-filling behaviour. Electrodeposition in Ca-Mg nitrate solution
resulted in extensive internal crack filling reaching the steel-concrete interface, independent of crack
geometry and width (maximum surface crack width 0.75 mm), and no corrosion was observed. In
contrast, electrodeposition treatment in artificial seawater resulted in deposits primarily near the crack
mouth and an influence of crack geometry. In these specimens, corrosion was prevented in two
specimens and reduced in the third. The findings demonstrate that electrodeposition can delay corrosion
initiation in cracked concrete when sufficient internal crack filling is achieved.