Vacuum Controlled Specimen in 250kN Load Frame requiring no triaxial cell

GDS have a unique system for testing large samples without the use of a triaxial cell. The unsaturated sample is prepared within a specially designed compaction mould, before effective stress is applied to the sample by means of a GDS vacuum controller, which can accurately apply negative pressure between atmospheric pressure (0kPa) and -75kPa, depending on the source vacuum pump being used. This allows the sample to be consolidated with negative pore pressure and confining pressure at atmospheric.

The vacuum controlled technique allows a larger size of sample to be used in the frame than wouldn't be possible if using a triaxial cell.  Triaxial cells of this size are bulky and also costly items, with sample preparation time significantly reduced without the need for a cell. In addition to the simplicity and speed, having the sample open to atmosphere allows for multiple radial displacement belts to be easily installed and adjusted.

This type of sample preparation can be ideal for tests such as resilient modulus testing. A specially designed sample preparation table is provided running on linear guides so that the sample can be slid out of the load frame for easy sample preparation and removal.

Product Datasheet