Uniaxial compression test and unconfined compression test both are same?

[VIRANGA]

Actualy I have no idea about the uniaxial compression test. I want to know , both tests are same?

 

[LRJ]

Yes.

 

[Ron]

Consider an orthogonal axis system (X,Y and Z). When the term "uniaxial" is used, it means "along one axis". This is generally taken to mean the long axis or loading in the "Y" direction. For soil with reasonable shear strength and for concrete, this loading is done vertically without "confining" or loading the other two axes, X and Z. Compare this to a triaxial shear test on soil where the X and Z axes are loaded to confine or constrain the sample with, generally, a constant load as the vertical load is applied.

That's a long-winded way of agreeing with LRJ!

 

[VIRANGA]

Thanksss

 

[Okiryu]

For these tests, as Ron mentioned above, just imagine how concrete cylinders are tested...

 

[fattdad]

I would not think a uniaxial compression test would exclude confinement pressure. Clearly, an unconfined compressive test does.

f-d

ípapß gordo ainÆt no madre flaca!

 

[Ron]

fattdad...I wrestled with that while I was giving my long-winded explanation. On the surface, uniaxial is just one direction loading. If there is confining pressure, it becomes triaxial, even if the confining pressure is minimal.

 

[fattdad]

. . . Ron, I guess you are right. I also figure I just use the term, "unconfined compression test." As the UU (unconsolidated, undrained TXC) is the means to add confinement, it'd clearly be a TXC by the ASTM.

nevermind. . .

f-d

ípapß gordo ainÆt no madre flaca!

 

[Ron]

f-d...agree. I would not think to use the term "uniaxial" for any unconfined compression test, whether soil or concrete.