The Rapid Chloride Penetratins Test (RCPT) is one of the most advanced and less time consuming durability test available to check the concrete durability. But my question is is it that much effective as testing the concrete
by keeping it inside the seawater or NaCl solutions?
The ASTM C1202 or AASHTO T277 test procedures should not be used in specifications without proper correlation to long-term tests. It is recommended that the table relating chloride penetration to coulomb values in these test procedures be removed since it is inaccurate and can be misleading.
Rapid chloride penetration test is to find the durability of concrete, whether the concrete is affected by chloride and rate of penetration.
But when the concrete is placed in a sea water or NaCl solutions, the amount of chloride present is very large amount and the durability value shown by RCPT test apparatus will give you false reading and shows that the concretes durability is very low.
Nordtest method (NT Build 492) is likely to be preferable over RCPT in terms of its reliability to durability characteristics under chloride exposure.
I agree with Lincy Varghese
But Nord test is not available in many of research institutes and consulting's.
And it has some limitations,
The method is applicable to test specimens from existing structures and to new samples older than 28 maturity-days. The concrete test specimens must be free from construction faults such as cavities and visible cracks.
It is important to keep in mind that the values for the chloride penetration parameters are dependent on concrete maturity. Especially concretes containing pozzolans will not have reached optimum maturity after a period of 28 maturity-days, which is the specified minimum curing time before exposure.
Deviations from the requirements of the method concerning exposure temperature, exposure time, together with the composition and the chloride concentration of the exposure liquid, can be made where required by the purpose of the test. In case of any deviations, it must be stated in the test report that the results are obtained from a modified test and the deviations must be specified.
Parameters of importance for the resistance against chloride penetration are e.g. composition, workmanship, surfacing, curing, age.
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