Hoek Cells for Rock Testing Equipment

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

• A cell body, 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.
• Lower cylinder with enlarged base and collar support that assures the vertical position of the cell even when not subjected to load.
• Upper lower loading cap with spherical coupling.
• One female spherical seating connected to the loading upper cap for the correct transmission of the axial load from the loading frame of the compression machine to the specimen.
• A rubber sealing sleeve 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. See accessories.

Measurements of axial and radial strain are carried out with the use of electric strain gauges, 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 (see) to complete and balance the Wheatstone bridge.

The strain gauge measurements can be performed by automatic or semi automatic testing systems (see Related Products below).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 Related Products).