Geotest offers a fully integrated line of pneumatic consolidation apparatus (designed by S.M. Sebestyen) ranging from a simple self loading chamber to a completely computer controlled system. All conform to ASTM D2435; AASHTO T216. Model S2845 also conforms to ASTM D4186.
Advantages of pneumatic loading have been well known for over 30 years. There is instant load application without shock; since weights aren’t used, any size sample up to 4” diameter can easily be tested; ambient vibrations have no effect.
Back pressuring allows the sample to reach approximately 100% saturation. This reduces the system to soil and water and eliminates errors caused by compressing entrapped air and gas. This is particularly important at low consolidation loads.
Consolidation loads from 1 / 2 to 40 tsf on a 2.5" diameter sample are maintained by means of a precision regulator which affords excellent stability. A second precision regulator controls back pressure during the duration of the test.
Consolidation strain is measured by a digital dial indicator allowing electronic data acquisition and interfacing to a PC.
A special feature permits selection of single or double drainage. By following a simple procedure, the approximate degree of saturation can be determined.
Sample preparation is simple. A cutting shoe and spacer block, S2855, is used to prepare a perfect 2.5x1" sample. The cutting shoe fits in a recess in the top of the consolidation ring. The upper porous stone is then used to gently push the sample into the teflon coated ring. Teflon coating decreases friction between the wall and the sample making the ring excellent for any type sample.