Calcium Carbide testing and Silicates

[CC Solutions]

Bill,
Let's think about this for a moment and see if we can figure the answer out ourselves.

Do the test parameters limit the concrete sample to the top treated horizon of the concrete only? I am assuming it does. The top would be the driest concrete horizon.

The next thing to consider is the test results we expect to see. Carbide testing is going to tell us the percentage of water in a sample. Flooring manufacturers want to know one of two things: The moisture vapor emission rate (MVER) or the concrete's relative humidity (RH). These tests are governed by the ASTM's associated with them for use by the flooring industry and have exact protocols that must be followed for the test to reveal usable results.

ASTM F-2170 for in-situ RH testing dictates reading the concrete slab at the 40% depth horizon for a reason. It has been determined through scientific testing that the 40% depth horizon accurately represents the moisture content of the slab while it is drying and at equilibrium. If the carbide test is only reading the top horizon of the concrete what good will that be? Likewise if we carbide tested the bottom of the slab what would that show us? The top would be drier than the bottom, but what does that mean? We have no manufacturers that recognize carbide testing at any horizon and specify a moisture acceptance level.

It could be a valid test if properly performed, which I would suspect would mean coring an entire profile piece from the concrete, full depth, and determining the moisture content of that piece. That will quantify the moisture content of that piece of concrete. But we still don't have a flooring manufacturer that recognizes the test and specifies a moisture content level.

So to answer your question, remind you I am not familiar with the test, yes you can test the free moisture content in a sample of concrete treated with a silicate. But what will it tell you?

I'd start with the question first, asking what you are supposed to find with this test, then we can determine if the test is appropriate.