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Constant Rate of Strain Consolidation (CRS) Test System

What is the Constant Rate of Strain test?

Constant Rate Consolidation Data Sheet
Sample Geotechnical Report

LoadTrac III/FlowTrac II or III

The LoadTrac III / FlowTrac II or III system fully automates the performance of a Constant Rate-of-Strain Consolidation (CRS) test. Once a soil sample is in place, and the test conditions selected, this system will run the entire CRS test from start to finish. The LoadTrac III / FlowTrac II or III system consolidates the sample through a loading path specified by using constant rate of strain loading. The FlowTrac II or III is used during the back pressure saturation as well as maintaining a constant cell pressure during the consolidation phase of the test. To avoid running the test too fast or too slow, the system uses Excess Pore Pressure Ratio Limits.

Applicable Test Standards

  • ASTM D4186
  • ISO/TS 17892-5


  • A typical test can be completed in 24 to 36 hours on most materials
  • Tests can be run as constant rate of strain, constant rate of stress, constant gradient, or constant pore pressure ratio
  • Fully automated via computer or standalone capability for control and data collection
  • Micro-stepper, electronic motor systems offer high speed, precise loading, and highly accurate automatic volume & pressure control
  • More accurate, reliable, and easier to maintain than units requiring hydraulics or air pressure
  • Immediately produce reports according to test standards
  • Front panel display and keypad for observation and control of the test
  • Geo-Net compatibility allows access and control over a computer network
  • System flexibility to optionally perform Constant Rate of Consolidation, Unconfined Compression, and Triaxial testing


LoadTrac III Load Frame:

  • Capacity: Up to 11 kN (2,500 lbs)
  • Rate of displacement: 0.000013 to 42 mm/min (0.0000005 to 1.6 in/min)
  • Platen travel: 38.1 mm (1.5 in)
  • Dimensions: 305 x 381 x 838 mm (12 x 15 x 33 in)
  • Weight: 20 kg (44 lbs)

FlowTrac II Pressure & Volume Control Flow Pump:

  • Capacity: 250 cc or 750 cc
  • Pressure: 200 psi (1400 kPa) or 500 psi (3500 kPa)
  • Volume rate control: 0.0003 to 1054 cc/min (0.00001 to 36 fl oz/min)
  • Dimensions: 203 x 406 x 470 mm (8 x 16 x 18.5 in)
  • Weight: 14 kg (30 lbs)

FlowTrac III Pressure & Volume Control Flow Pump:

  • Capacity: 200 or 280 cc
  • Pressure: 150 psi (1035 kPa) or 200 psi (1400 kPa)
  • Volume rate control: 0.0003 to 1054 cc/min (0.00001 to 36 fl oz/min)
  • Dimensions: 457 x 203 x 260 mm (18 x 8 x 10.25 in)
  • Weight: 11 kg (25 lbs)

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