Insights into chloride ion transport in alkali-activated slag concrete subjected to load damage and leaching

The study investigates the Cl⁻ transport behavior of alkali-activated slag concrete (AASC) under the combined effects of loading and flowing NaCl solution. The results indicate that, within the same corrosion age, the total Cl⁻ concentration and the combined Cl⁻ concentration decrease as the depth of penetration increases. At a given depth from the surface of the AASC, the total Cl⁻ concentration increases with the extension of the corrosion age. At the same time, the combined Cl⁻ concentration initially rises and then declines with the increase in corrosion age. The dissolution effect of flowing corrosive solutions dissolves and precipitates alkaline substances in AASC, reducing the pH of pore solution, leading to the destabilization and decomposition of hydration products, and promoting the transmission of Cl⁻ in AASC. Meanwhile, load application is prone to causing damage to AASC, accelerating the transmission of Cl⁻. When the load is doubled, the concentration of combined Cl⁻ in the tensile zone of concrete at the same depth increases by up to 67.24% at the same age. When loads and flowing solutions act together, load-induced damage and dissolution mutually reinforce each other, further accelerating Cl⁻ transmission.