Mexe Probe to CBR Correlation 1

[Madziwa]

Does anyone have a correlation between CBR and the Mexe-Probe or from Newtons to CBR? We have a SACP (Mexe-Probe) from CNS Farnell that has been calibrated but the calibration only gives us CBR vs Newtons.

Can anyone help?

 

[Focht3]

Please restate your problem - I don't see what your issue is -



Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Madziwa]

The calibration that has been done has provided a graph relating the Dial readings marked "CBR", to Newtons. What I was asking is if anyone knows of the correlation between Newtons and the real CBR value. Basically I need to be able to read the dial reading and then read off a direct CBR value, similar to using a hand shear vane and taking the dial reading and converting that to a su reading.

HAving done some more checking yesterday I found reference to an Airfield Cone Penetrometer used by the US military. Is this the same as the SACP produced by CNS Farnell?

 

[Focht3]

DCP and CBR are different - this isn't the same as using a hand shear vane. It's more like a pocket penetrometer with an additional level of conversion/uncertainty.

Pocket pen: "bearing capacity" -> unconfined compressive strength
DCP: penetration resistance -> bearing capacity, bearing capacity -> CBR

I suspect the device's "calibration" is as good as it gets. After all, you only wanted an estimate, right?



Please see FAQ731-376 by [blue]VPL[/blue] for tips on how to make the best use of Eng-Tips Fora.

 

[Madziwa]

Yes we only need an estimate of the CBR. Its being used as a "control" tool for checking on fill compaction quickly. The only reason I mentioned the shear vane was that with a shear vane the engineer needs to take the dial reading and then correct it. Similarly with the SACP Mexe Probe, the engineer needs to take the dial reading and then correct it for CBR.