Ultrasonic Pulse Velocity as a Measure of Shotcrete Flexural Strength

[BigH]

G'day

Our contractor is proposing to carry out ultrasonic pulse velocity to correlate to flexural and energy absorption properties of a 100 mm thick fibre reinforced shotcrete.

I have read the various ACI sections on this . . . but was wondering if anyone actually had some "real" data on the efficacy of such a correlation.

Appreciate in advance if anyone can help.

Cheers

 

[Ron]

BigH....yes, I've used pulse velocity lots of times for compression correlation. It is ok for that if you do enough correlation points.

I would be skeptical of using UPV for flexural as the beams are difficult to fabricate consistently which will give more variation in the velocity than it will in the actual third point loading results. If you use UPV to correlate to splitting tensile, then flexural, you are dealing with a "double secondary correlation".

Also for beams, the correlation would have to be done orthogonally (in my opinion).

In short....I suppose it can be done, but I think it would require a lot of correlation effort. If project is large, it might be worth the effort though.

 

[BigH]

The big problem is that this is to be a study of existing shotcrete! They didn't take their QC seriously.

 

[Ron]

I would take lots of cores and do both compressive and splitting tensile correlations.

 

[BigH]

Splitting cores seems like a good idea . . .