We're almost at 3lbs MVER, so what if the rH is over 90% ?

[Rubensgt40]

(07-12-2012 01:04 PM)eaadams Wrote:  Yes there really is a gap in the concrete knowledge on this subject. I used to think the RH Hood method would help alleviate this but it hasn't.

I'd love to see a study on RH Hood tests done next to CaCl to see if there is any parallel.

Hoods are just so expensive... I put those GE probes in mine and they are guaranteed targets for lifts.

That would be interesting. I did side-by-side tests with a hood and RH @depth and the hood readings went UP past 72 hours.

I don't know if this is relevant but 1869 calls for light grinding of the surface, whereas the hood method 2420 calls only for "clean, bare concrete", and later says "considerable amount of additional time may be required for the satisfactory performance of the test because of low porosity surface...". I wonder if requiring a light surface grind for the hood might be a better idea.

F2420 has just been approved (published last month) for inclusion in our resilient flooring standard- but only where in-situ cannot be performed where drilling is innapropriate. So there's going to be some fast learning going on...