Electrical Current Flow or Rapid Chloride Permeability Test (RCPT)
This method is described in AASHTO T 277–831 "Rapid Determination of the Chloride Permeability of Concrete" and ASTM C1202.
It was originally developed to provide a rapid test method that correlated well with ponding tests which are considered to be the best method of determining the chloride permeability of concrete but they take a long time, making them impractical for certain applications such as quality assurance testing.
The test consists of monitoring the amount of electrical current passed through 95mm diameter by 51mm long cores when one end of the core is immersed in a sodium chloride solution and a potential difference of 60V dc is maintained across the specimen for 6 hours. The total charge passed, in coulombs, is related to chloride permeability.
However, in a critical review of Rapid Chloride Permeability testing (RCPT) one author concluded that there is no correlation between the results of RCPT and the more conventional ponding tests.