The Rapid Migration Test for HPC

This paper described how chloride-induced corrosion is a major cause of deterioration of reinforced concrete structures. The best method of minimizing the problem is by producing high quality concrete that is capable of resisting the ingress of chlorides. To ensure quality concrete, it is necessary to have a measure of the concrete's ability to resist chloride ingress that can be used as a standard test. The traditional test that has been used for this purpose is AASHTO T 277 (ASTM C 1202), commonly referred to as the Rapid Chloride Permeability Test (RCPT). This test, while providing a rapid indicator of concrete's resistance to fluid penetration, does have a few drawbacks, principally: (1) the current passed is related to all the ions in the pore solution, not just chloride ions; (2) the high voltage leads to temperature increases during the test, which affects the properties of the concrete; and (3) a relatively high variability. To overcome some of these drawbacks, the FHWA sponsored an investigation of various alternative test methods.