Reconstituted clay Triaxial testing
Reconstituted clay Triaxial testing
(OP)
I am trying to perform CD Triaxial tests on Kaolin clay. I assume the clay powder is to be mixed with water more than the liquid limit and sand can be added to make the saturation process faster. Can any one provide any information about the procedure to prepare an intact cylinder from a the clay slurry?





RE: Reconstituted clay Triaxial testing
I think you will need to consolidate the mixture in a mould using a consolidation plate with drainage at top and bottom.
RE: Reconstituted clay Triaxial testing
In the triaxial cell, it's more likely that you'd have to place the LL sample into a static load machine to get the target density, then extrude to a triaxial cell.
I guess your end game is fully-softened strength and/or residual strength? In that regard, I'd just go to the DDS.
f-d
ípapß gordo ainÆt no madre flaca!
RE: Reconstituted clay Triaxial testing
@fattdad : I am looking at the effects of temperature on the pore pressure and volumetric changes so I need to perform CD tests on Kaolin and maybe with some sand to make the consolidation faster.
RE: Reconstituted clay Triaxial testing
RE: Reconstituted clay Triaxial testing
If you have to start above the liquid limit for some reason then you'll need to do your sample preparation in a mould mounted on the triaxial apparatus, as EireChch suggests, because the slurry would be too fragile to transport.
The shearing stage of a CID on clay needs to be slow enough to ensure excess pore-water pressures don't develop. Adding sand will help the excess pore-water pressure dissipate more quickly, so you can shear the sample more quickly. It is this shearing stage of a clay CID which takes a long time; the consolidation stage is comparatively short. Also as EireChch suggests, two-way drainage will help speed things up a bit, though I wouldn't recommend doing it during the consolidation stage since you want to make sure your initial PWP reading at the start of shearing (i.e. end of consolidation) accurately reflects the PWP throughout the sample.
RE: Reconstituted clay Triaxial testing
@LRJ :I think also the saturation stage of the triaxial test will take a very long time
RE: Reconstituted clay Triaxial testing
RE: Reconstituted clay Triaxial testing
I didnt use a consolidometer. I think its too small for what you are intention. We literally used a perspex mould 200 x 200 x 500mm high. We mixed the slurry and filled it to 400mm height and then applied pressure through a plate connected to a pneumatic pump. After approx 5-7 days of applying pressure, the sample reduces in height to approx 200mm.
See my previous thread before where i was having problems with a steel mould.
http://www.eng-tips.com/viewthread.cfm?qid=426956