Relationship between cations migration parameters and current density of accelerated lithium migration technique

10 cm-diameter, 3 and 5 cm-high mortar specimens were used, with an aggregate/cement ratio of 2.25, water/cement ratio of 0.5, and fine aggregate gradation conforming to the requirements of ASTM C227. The alkali content of the cement was adjusted by NaOH to be 2.0% Na ₂O _eq. After curing for three months, 6~21 A/m ² constant-current-density Acceleration Lithium Migration Technique (ALMT) experiments were performed. As indicated by the experimental results, the system resistance of the ALMT experiment is proportional to the length of specimen. The Na ⁺ and K ⁺ complete removal time and the time for Li ⁺ passing through the specimen were decresed with increasing current density. The applied constant current density of 6 A/m ² can remove about 87% alkali in the specimen. Increasing the current density, the increment of removed alkali is limit, but it can reduce the complete removal time. The increased applied current density is conducive to the increased proportion of the applied current applied for cation migration. The 0.0011 ~ 0.0012 cation transference numbers can be increased for every 1 A/m ² increase of current density. Shorter specimen length can increase the proportion of the applied current applied for cation migration.