The direct shear test measures the force and horizontal displacement of a representative soil specimen that is sheared along a controlled horizontal plane at a constant rate of deformation. Typically three or more tests make up a series and are combined to determine strength properties such as Mohr strength envelopes.
Gilson’s direct shear testing equipment includes direct shear machines that meet ASTM D3080 and AASHTO T 236 test standards. Select models measure residual shear forces and Gilson's geosynthetic shear machine which meets ASTM D5321 and ASTM D6243.
- Pneumatic Direct Shear Machines are self-contained units using pneumatic pressure for application of vertical loads from 4-100lb (0.018 to 0.44kN), or up to 1,500lb (6.67kN). They are available outfitted with digital or analog instrumentation for measurements of force and displacement and evaluate direct and residual soil shear strengths up to 1,500lbf (6.67kN).
- Dead-Weight Direct Shear Machines is compact, and provides direct and residual shear testing of undisturbed and remolded soil samples. It is built to withstand a harsh laboratory environment. This machine uses a 10:1 mechanical beam device and manual weights to apply vertical confining loads.
- High Capacity Geosynthetic Direct Shear Machine measures total resistance to horizontal shear forces of 12in (305mm) square soil or soil/geosynthetic samples. Models available with pistons that can generate loads up to 45 or 90kN (10,000 or 20,000lbf).
- Shear Boxes are available in round or square configurations, and in a range of inch or metric sizes. These accessories allow opposing shear forces to be applied to soil specimens that have been carefully trimmed to fit.
- Direct Shear Accessories include porous stones, cutters, and extruders used with correlating-sizes of Shear Boxes. These items are available in a range of metric and inch sizes, in a round and square shapes.
- Weight Sets are used in dead-weight consolidation or direct shear soil testing and are available in pounds or kilogram sets. Sets are comprised of individual weights of sequential sizes.
- Direct/Residual Shear Data Acquisition Software records specimen and real-time test data, calculate results, and prepares reports following ASTM and AASHTO requirements.