Differences in Sand Cone Side by Side Tests
Differences in Sand Cone Side by Side Tests
(OP)
I do independent assurance testing in our department. One of the issues I face is when doing a side by side sand cone test with another technician we are at times 4 - 6 pounds different on our wet density. These tests are done no more than a foot away from each other in the same material. It is my job to determine where the error is and correct it. Other than the sand and cone calibration, what would be some other aspects to look at that may cause this much difference in wet density? This occurs at times in both granular material and soils.





RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
master ICC inspector, AWS CWI
RE: Differences in Sand Cone Side by Side Tests
While it is good to check the computational procedure, if something is off in the 4th decimal place, it would not yield a significant difference in the end result.
RE: Differences in Sand Cone Side by Side Tests
RE: Differences in Sand Cone Side by Side Tests
What is the material? If its some crushed rock product, i can see some variation in the digging of the hole and the transferring of the material. ( I once had to do a SCD in CR6 for a second Lt of the Army Corps. I told him the disturbance of the material while digging would make the result inaccurate. He didn't care--the spec said to do a SCD. I did the SCD and made sure that I disturbed the hole sides while digging so that the result was about 115% of the ASTM D1557 density. The office was happy and then went on his way.) The point is that is possible to dig the SCD hole in a way to slant the results---if that is desired.
RE: Differences in Sand Cone Side by Side Tests
have the techs switch equipment and redo...
take the remainder of sample to moisture test in the lab oven, does it match field burns?....
push both spots with your thumb before you test, do they seem similar...
Google "Hawthorne Effect"...