Soil Resilient Modulus Machine
MRT Resilient Modulus Testing System

The GCTS MRT Resilient Modulus Testing System is based on the GCTS cyclic triaxial device and complies with the requirements of AASHTO, SHRP, ASTM, and NCHRP. The GCTS resilient modulus software features built in AASHTO, SHRP, and NCHRP test sequences for an even easier testing experience.


  • Electro-Hydraulic (Electro-Pneumatic for MRT-050) Digital Servo Control
  • Complete “turn-key” system
  • Easy to use software for automatic test performance
  • Meets AASHTO, SHRP and ASTM standards
  • Triaxial cells for specimens from 71 mm (2.8 in.) to 150 mm (6 in.) diameter
  • Available indirect tension fixtures to perform ASTM D4123 and SHRP P-7

The GCTS Resilient Modulus Testing System (MRT Series) boasts a modular design which allows the system to be configured to test soil in a variety of modes. This system is based on the GCTS SCON Digital Signal Conditioning and Controller and can be supplied with a pneumatic or hydraulic loader.


The GCTS Resilient Modulus software features built in AASTHO, SHRP, and NCHRP test sequences and the capability to specify user-defined sequences. Contact stress is automatically adjusted according to each procedure as selected. Available waveforms include haversine, sine, square and triangular, along with a user-defined waveform selection. Optional peak and valley compensation ensures proper and quick matching of the load parameters. Real-time displays of the prescribed versus actual dynamic load and the dynamic deformation measurements by each sensor are always present.


The deformation ratio of the two sensors, Rv (to ensure that the two deformation sensors are in agreement), and resilient modulus, Mr, are also calculated in real-time. During export, curve fitting is done to match the results to models that predict Mr as a function of σm, σd, and cell pressure (CP). Four different functions are calculated automatically, as required by AASHTO and NCHRP procedures.


The MRT-300 can test specimens with a 70 mm, 100 mm, or 150 mm diameter, although it is recommended to use a smaller system for 70-mm diameter specimens, such as the GCTS Electro-Pneumatic Resilient Modulus System (MRT-50). All standard systems include the required dual external deformation sensors with supports and internal/external load cell.


This GCTS Device is a sound and well-integrated system designed to perform Resilient Modulus tests, as well as standard triaxial (static and dynamic) tests and other, more complex, tests, such as Complex Modulus tests.


Model No. Type Sample Diameter
MRT-050 . . . . . . . . Pneumatic . . . . . . . . 70 mm
MRT-100 . . . . . . . . Hydraulic . . . . . . . . . 70 mm
MRT-200 . . . . . . . . Hydraulic . . . . . . . . . 70 & 100 mm
MRT-300 . . . . . . . . Hydraulic . . . . . . . . . 70, 100, & 150 mm

(see brochure for full specifications)