when to replace the Liquid limit grooving tool

[danyul]

so there is info on the starting dimensions for the liquid limit grooving tool but is there an official replace the tool guideline?

thanks

 

[TDAA]

ASTM and AASHTO give +/- tolerance for each measurement. If it is outside that, then replace.

 

[Ron]

Look at the required new dimensions for the grooving tool required by ASTM D4318, Figure 3.

 

[vulcanhammer]

I don't know how this squares with ASTM, but EM 1110-2-1906 states the following:

"Inspect grooving tools for wear on a frequent and regular basis. The rapidity of wear depends on the material from which the tool is made and the types of soils being tested. Sandy soils cause rapid wear of grooving tools; therefore, when testing these materials, tools should be inspected more frequently than for other soils. Any tool with a tip width greater than 2.1 mm must not be used. The depth of the tip of the grooving tool must be 7.9 to 8.1 mm. The width of the tip of grooving tools is conveniently checked using a pocket- sized measuring magnifier equipped with a millimeter scale. Magnifiers of this type are available for most laboratory supply companies. The depth of the tip of grooving tools can be checked using the depth measuring feature of vernier calipers."

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