X-ray computed tomography data - specimen H6: "The Interdependent Roles of Chloride, Moisture and Dissolved Oxygen in Macro-voids at the Steel-Concrete Interface in Corrosion"

Under wet-dry cycles, corrosion initiated at lower chloride levels than under continuous immersion. XCT revealed that interfacial voids became fully saturated after prolonged immersion but remained partially saturated during wet/dry exposure. These findings are interpreted through the lens of corrosion science and gas-liquid interactions in porous materials.

We suggest a mechanism in which the dissolution of pressurized gas bubbles trapped within interfacial voids leads to an increase in dissolved oxygen concentration near the void, thereby locally elevating the steel corrosion potential (E_corr). Together with chloride accumulation, which gradually lowers the pitting potential, this shift in E_corr enhances the likelihood for local corrosion initiation under wet-dry cycles.

Overall, this study contributes to understanding how different water exposure conditions affect the local environment at the SCI, providing insight into the mechanistic links between interfacial void gas-liquid content and corrosion in reinforced concrete.