The Hoek triaxial cells are offered in four models of different size; each one consists of the following:

• A cell body (1), complete with two quick release self sealing couplings, for the introduction of the hydraulic oil and cell pressure, and for  air outlet  and saturation of the chamber respectively.
• Two end caps (2), screwed into the cylindrical cell body.
• Upper (3) and lower loading caps (4) with spherical coupling.
• Two female spherical seating (5) connected to the loading caps (3) and (4) for the correct transmission of the axial load from the loading frame of the compression machine to the specimen.
• A rubber sealing sleeve (6) to separate the specimen from the cell fluid.

Although each sleeve can be used for several tests, an order of five spare sleeves is recommended.

Measurements of axial and radial strain are carried out with the use of electric strain gauges (7), both in vertical and horizontal direction, directly glued on the lateral surface of the specimen. The wiring connections are passed within the rubber sleeve  trough the cell body and loading cap. Each strain gauge must be connected to a proper device to complete and balance the Wheatstone bridge. The cell pressure and saturation pressure for permeability tests are carried out by the use of appropriate equipment.

It is also recommended the use of a Specimen extruder , to extrude the rock sample from its jacket thus avoiding to empty the confining fluid. See accessories.

Used to extrude the rock sample from its jacket thus avoiding to empty the confining fluid. It consists of a steel frame with a rack and pinion mechanism.

Supplied without adapters. See the following table.

Extruder Adapter set code	For specimen size	For use with cell	Weight approx.
G563-45-D0577/1	AX	45-D0553	1.7
G563-45-D0577/2	1.5 in.	45-D0554	1.7
G563-45-D0577/3	BX	45-D0555	1.5
G563-45-D0577/4	NX	45-D0556	1.5