RCT and RCTW
A powder sample is obtained from hardened concrete by drilling or grinding (Profile Grinder) or obtained from the fresh concrete. The sample is mixed with a specific amount of extraction liquid that is designed to remove disturbing ions, such as sulfide ions, and to extract the chloride ions in the sample. After 5 minutes, a chloride ion selective electrode is submerged into the solution to determine the amount of chloride ion by means of a calibrated chart, which is expressed as percentage of concrete mass.
Two methods can be used: The RCT (Rapid Chloride Test) is used to determine the amount of acid-soluble chlorides. The RCTW (Rapid Chloride Test Water) is used to determine the amount of water-soluble chlorides.
Rapid Chloride Content Test.