Forum Message



Name:   
Heading: 1.1.1.1Moisture in Sand
Message:
As many of us know, before making a concrete batch, we have to determine the percentage of evaporable moisture (surface and pores) of the aggregate (in this case, the fine aggregate).

Based on Laboratory Trial Mixes...

The QUESTION is this:

Is there another reliable test method to determine the Moisture in Sand BESIDES the explained in ASTM C 566 (oven drying)?




---------------------------------------------
Jorge Moquete


The short answer to your question is NO. ASTM C566 IS the standard test method. It is the only method. It's called a "burn-off" and it's used every day by Ready-Mix QC and field technicians. It is more reliable than electronic monitors and is used to verify that the bin monitors are accurate. A quick search of the current (2009) ASTM standards for Concrete and Aggregate using "moisture" as the search term returns 9 ASTM Standards, only one of which is used to determine the moisture content of aggregates. C566-97(2004)The Ready-Mix Concrete Association may have other information, but why are you looking for another method when the current standard is the simplist and most accurate if performed correctly?
---------------------------------------------
Bob Miller


I appreciate all the replies.

Bob, i'm looking for another method, because the ASTM C566 is not the FASTEST.

If you take very moist sand and put it in the OVEN, it will take forever to dry it, considering 230F (110C) temperature, as it's explained in the ASTM C566.

I could use a rapid heat source, like a stove, but particles may suffer loss.

In conclusion, i need: QUICK AND RELIABLE.
---------------------------------------------
Jorge Moquete


I have used something called a Speedy Moisture Meter in the past. You can see info about it here:

http://www.humboldtmfg.com/c-7-p-468-id-7.html

Basically the device is a pressure meter. You combine calcium carbide (remember the old Big Bang Cannons?) with the damp sand. The calcium carbide gives off acetylene gas and you measure the pressure rise in the vessel. The more moisture the higher the pressure.

Meets ASTM D4944 and AASHTO T217.

Jay
---------------------------------------------
Jay Shilstone
 
   Click Here to Reply    Areas
Advertise Here