Soil and Asphalt Direct Shear Testing Equipment
SDS-300 Direct Shear Testing System for Soils & Asphalts

The GCTS SDS-300 Direct Shear Testing System for Soils & Asphalts is an excellent device for determining the shear strength of soil or asphalt specimens. This system features closed-loop digital servo control of the axial and shear load actuators and can be easily programmed to perform both constant normal stress and constant normal stiffness tests.


  • Closed-loop servo control of double acting (push/pull) 100 kN (10 ton) shear load actuator with 100 mm stroke & 100 kN (10 ton) normal load capacity with 50 mm stroke
  • Normal load reaction support mounted on sliding bearings to minimize horizontal friction
  • Accepts 300 mm (12 in.) square specimens
  • Software for automatic performance of direct shear tests with constant normal stress or constant normal stiffness
  • Available interface platens to test soils, asphalt and geo-membranes
  • Other load capacities & specimen size dimensions are available, including large-scale test systems for shear loads of up to 1,000 kN (100 ton) & specimen sizes up to 300 mm diameter or side
  • Shear speed variable from 0 mm/sec to 500 mm/sec

The GCTS Direct Shear Testing System for Soils and Asphalts (SDS-300) features electro-hydraulic closed-loop digital servo control of the shear and normal loads for test automation. Loads or deformations for both the shear and normal actuators can be prescribed for automatic performance of conventional direct shear tests as well as more advanced tests. This system can be easily programmed to perform tests such as the constant normal stiffness test where the normal load is a function of a prescribed stiffness for simulating actual compressibility of a ground shear plane (e.g. soil-pile interaction).


The SDS-300 is especially well-suited to test coarse granular materials and simulate interface materials because of its high load capacity, ability to accommodate large specimens, and elimination of vibrations that can disturb or compact granular specimens.


Included with this system are loading plates with a square grid of retractable pins that help to grab different types of samples, such as soils, asphalt and other materials. Also included is a water reservoir to submerge specimens during testing.


The top shear box can be horizontally translated and the bottom shear box is mounted on sliding bearings to minimize friction. Set screws with nylon tips are used to adjust the shear gap. The top shear box is suspended on springs to balance its weight, causing normal load readings to be extremely accurate. The shear boxes also ensure that shear transfer is done through the top of the shear boxes rather than the sides, making this system the most accurate large scale direct shear testing system on the market.


  • 100 kN axial load capacity
  • 100 kN shear load capacity
  • 300 mm x 300 mm x 200 mm maximum specimen size


Please contact GCTS for full specifications.