Matest Laboratory Vane apparatus represents a valid alternative to the most common standard triaxial equipment whenever a rapid estimation of the undrained shear strength of a soil specimen is required.
Based on the original design by the UK Transport Research Laboratory, this apparatus allows the application of stress to the soil sample as a function of the specific calibration spring and vane used (see accessories).
The choice of the spring and vane to be used is made according to the specific soil strength which is expected to result from the test, however, larger vanes are demonstrated to be suitable when soils having low-strength values are considered.
The working principle of the apparatus is governed by the rotation of the vane into the soil sample, while the calibrated spring provides the measurement of the applied torque. In addition, two different graduated scales are present on the instrument; one for the applied torque (inner scale) and another for the vane rotation (outer scale).
Finally, at the end of the test, the Undrained Shear Strength (cu) is calculated by a formula dividing the applied Torque (T) by a constant (K) which directly depends on the dimensions and shape of the chosen vane.
The vane apparatus is supplied complete with four calibrated springs and a vane Ø 12.7 x 12.7 mm.
Dimensions: 250x300x600 mm
Weight: 10 kg approx.
