Standard for determining density of sand used for sand cone testing??? 1

[Andy J]

Is there any specific standard out there used for determining the density of the sand used for sand cone testing?

 

[oldestguy]

I have done this check having the sand come out of the cone directly into a known volume, but at the time didn't know of a standard. Tried to duplicate the field situation.

 

[mikeofBelAir]

ASTM D1556 has several requirements for density sand. Max particle size, uniformity, free-flowing, etc, but no specific requirement for its density. Most that I have used was right around 90 pcf give or take a pound or so.

 

[PEinc]

It should not matter what the density of the sand is. The sand is a uniformly graded, cohesionless material (like Ottowa sand) that is used to determine the volume of the hole from which a then-weighed amount of soil has been excavated. Soil weight and hole volume give the in-place density of the soil.

http://www.PeirceEngineering.com

 

[oldestguy]

Quote: "It should not matter what the density of the sand is.". Then how is volume of hole known without knowing density of that loose stuff?

 

[PEinc]

The known weight of uniformly graded sand should fill a consistent volume when properly poured into a container of known volume. If you know how much sand filled the hole, you can figure the hole volume. Check out this You Tube video.

https://www.youtube.com/watch?v=ojH0W3xq3P0

http://home.iitk.ac.in/~pkbd/Lab-DensitySandCone.html

http://www.PeirceEngineering.com

 

[oldestguy]

I've run piles of these tests so my question is from the post above "If you know how much sand filled the hole", So how do you know the answer to this without weighing anything?

 

[PEinc]

The excavated soil needs to be weighed. Check the You Tube video. It shows a test.
The sand gives the volume. The weight of soil divided by the volume gives the in-situ density. Then the moisture is checked in a lab.

http://www.PeirceEngineering.com

 

[oldestguy]

Unuff of this fun. Have a good nite. A funny story. I once was asked by a contractor to write a report on the suitability of a farm field for a sanitary landfill. Some "do-gooder" didn't like the idea and got a university soil engendering professor to come out to the site where we were to do some test pits for my purposes. Prof was allowed to run any tests and sample as he might want. He and his assistant came to take samples, etc. They decided to take some field density tests using the sand cone method. They had no plate for support and the cone diameter was 4" diameter. Sample obtained was about the size of my breakfast coffee cup. Some of their amateur sampling was done also. Seeing this amateur field work, I photographed all of it, in case I'd have to go to court, etc. Imagine these guys teaching a soil mechanics class that an engineer was supposed to get some use out of? Well incidentally the engineering firm I was with once at one time hired a recent CE graduate from there. We had to re-train him to get any use from him. Anyhow I never had to face Prof in court or similar on this. I would have had a fun time I think. And he had his PE!!!

 

[MTNClimber]

Sounds about right. When you get out of college these days you have been exposed to topics but can’t perform a lot of basic tasks. It takes years of grooming to get someone up to speed, sometimes it’s not until when they are eligible to take the P.E. When I went to graduate school while working full time I had one professor constantly ask me, “Is how it’s done in the real world?” They we’re also a P.E. You only know what you know.

 

[Ron]

The standard procedure you need to determine the bulk density of your sand-cone sand is contained in Annex 2 of ASTM D1556, the standard in the US for the sand-cone test.