CUTX Consolidation

[Stoph]

ASTM D 4767-04 under section 8.3.3 During the consolidation phase the spec says to "record the accompanying deformation indicator readings by carefully bringing the piston in contact with the specimen cap."

With 60 to 80 psi cell pressure, it takes all the strength I can muster to push down the piston, how do I do this "carefully". My fear is that I would be applying load to the sample while bringing the piston in contact.

Second, we use a volume transducer to measure consolidation, but our lab certification agency says that we must be use this vertical deformation reading to verify that volume loss is not related to a system leak. Is this necessary and how do we perform it without applying load to the sample prematurely?

Thanks!

 

[iandig]

do it before you pressurise the cell, then pressurise the cell and record the initial reading, which is then subtracted from the readings as a correction.

 

[Stoph]

However, the spec says to take readings at different time intervals, not just the initial.

 

[iandig]

I will speak to our lab for you, they are UKAS for the test so they should know the full answer, only difference is they will be testing to BS 1377 not the ASTM, should be a problem though as they should be very similar.