Semi-automatic Uniaxial and Triaxial test system. Basic test apparatus

ASTM D2664 | ASTM D2938 | ASTM D3148 | ASTM D5407 | EN 14580 | EN 1926 | ASTM D7012
Main features
  • Suitable for determining elastic modulus and strength characteristics of rock specimens under uniaxial and triaxial conditions
  • Composed by 2 indipendent systems: high stiffness compression machine and low friction manual pressure maintainer
  • Max working lateral pressure: 70 MPa
  • Advanced external data acquisition system with new touch screen Datalog 8
General description
The Semi-Automatic configuration for determining the elastic modulus and strength characteristics of rock specimens is based on the compression machine with DIGIMAX control system for axial loading and manually-operated pump for confining pressure. It performs either uniaxial or triaxial tests under load/stress control (no strain).
The 2 systems are operated independently and the failure envelope is obtained by a series of individual tests (single - stage) with manual adjustment of the axial load and manual application of the confining pressure at different levels.

Note: For a typical configuration of an Semi-Automatic triaxial test system see Additional information.

  1. axial and confining stresses are independently increased isotropically up to a defined level: axial load is controlled by a special pressure-compensated proportional valve; confining pressure is controlled by the manual pump with pressure maintainer;
  2. cell pressure is maintained constant and axial stress is constantly increased by the pressure-compensated proportional valve up to specimen failure (single-stage);
  3. the procedure above is repeated N times using new specimens at various confining pressure levels. Combining these results it is possible to plot the failure envelope with N points using the dedicated MS Excel spreadsheet.
  4. strain values are acquired by Datalog 8 datalloger.

Technical specifications

Lateral pressure system
The 32-D0558 Low friction manual pressure maintainer is used for maintaining constant the desired lateral pressure in the Hoek triaxial cells. The unit comprises a hand pump connected to a special oil reservoir, a precision pressure gauge, a pressure maintainer and a flexible hose 3 m long with a 90° quick release coupling.
  • Max working pressure: 70 MPa
  • Weight approx.: 15 kg

Ordering info

Compression machine
Wizard Auto compression Testing  machine 3000 kN cap. with Semi-automatic Uniaxial and Triaxial test system, manually-operated with pump 32-D0558, Hoek cell NX type 32-D0556 and Datalog 8 channels 82-P9008. 230 V, 50 Hz, 1 ph
For more info see link to other products below

Lateral pressure system
Low friction manual pressure maintainer for lateral pressure


Please refer to the links to other products below for more technical and commercial info about:
  • Compression frames
  • Hoek cell and sample extruder
  • Strain gauges for uniaxial and triaxial tests
  • Compression device for uniaxial tests
  • Multipurpose data logger

Additional Information

Typical configuration of a standard semi-automatic system for uniaxial and triaxial tests on rock specimens
Code Description Uniaxial
50-C56W02 Wizard Auto Compression testing machine 3000
kN cap.
1 1
50-Q0050/HRD Upgrading of the 50-C46xx and 50-C56xx series 
compression frames with upper and bottom platen dia 300mm min. hardness 58 HRC
1 1
50-C0050/CAL Special calibration procedure assuring
Class 1 from 1% of full scale
1 1
50-C9086/P Distance piece dia. 200x100 mm 1 -
50-C9083/P Distance piece dia. 200x68 mm 2 1
50-C9080/P Distance piece dia. 200x30 mm 1 -
Code Description Uniaxial 
32-D0558  Low friction manual pressure maintainer - 1
32-R0023 Three way connector 1 2
82-P0700 Pressure transducer 700 bar cap. 1 2
82-P0349/ELT              Connection cable to Datalogger             1 2
HOEK CELLS (different sizes available. We propose NX model.
Code Description Uniaxial 
32-D0556 Hoek cell, NX 54.7 mm dia. - 1
32-D0556/A Pair of load spreader - 1
32-D0556/B Distance pad - 1
32-D0556/1 Spare rubber membrane - 5
32-D0577/B Rock sample extruder - 1
32-D0577/4 Extruder adapter set for NX specimens - 1
Code Description Uniaxial
32-D9035 Compression device for samples up to 55mm diameter x 110 mm height 1 -

STRAIN READING (select the suitable strain gauges within the models listed below)
Code Description Uniaxial
82-P9008 8 channels stand alone multipurpose data logger 1 1
82-P9008/ELT Set of four connection cables 1 1

82- P9008/SOF               
DATACOMM 2 data acquisition generic software 1 1
82-P0398 Electric device to complete and compensate up to four Wheatstone bridges with ¼ or ½ bridge set up 1 1
82-P0399/C Strain gauge application kit 1 1
82-P0399/1 Connecting terminals. 50 pairs sheet 1 1
82-P0390 Strain gauge, grid width 4.53x9.53 mm. Pack of 10 1 1
82-P0391 Strain gauge, grid width 3x20 mm. Pack of 10 1 1
82-P0392 Strain gauge, grid width 2x30 mm. Pack of 10 1 1
82-P0393 Strain gauge, grid width 1x60 mm. Pack of 10 1 1
MS EXCEL Template for stress/strain analysis, Elastic Modulus and Poisson's ratio processing in uniaxial and triaxial tests (single stage)        
1 1