using soil sample more than once

[civilQ]

hi
what's the risk of using soil sample in more than one test ? like re-compacting a sample that already undergo CBR test and testing it again with different density or using a tested unsoaked CBR specimen for soaked test ?
does CBR test or proctor test crush's soil particles ?

 

[oldestguy]

"does CBR test or proctor test crush's soil particles ? " Yes, Yes. Sometimes the reason why the poor contractor can't get the specified density due to higher lab result on a better gradation result of the lab compaction.

 

[Ron]

Yes, there can be a gradation change during testing, particularly if using a graded aggregate base material (one that would commonly require CBR testing). While it might be possible to re-use the sample, you would have to prove its validity. If your results were called to question, particularly in a litigation stance, you would be criticized for not following the standard, which requires a separate sample for each test and prevents reuse of previously compacted samples.

Just get additional sample material and run independent test specimens....then you won't be criticized for that reason at least!