Soil Back Pressure Consolidometer

Soil Back Pressure Consolidometer

Soil testing is an important part of geotechnical engineering to determine the properties and behavior of soil specimens. This information is required for designing and building pavements, structures and other infrastructure projects. One of the tests used in soil testing is the consolidation test, which measures the compressibility of soil specimens under various conditions. The consolidation test is used to measure the compressibility of soil specimens under a given load. The test is used to measure the compressibility of soil specimens under a given load. The test is performed on soil specimens which are prepared by compacting soil into a stainless steel compaction ring. The specimen is then placed in the consolidometer between two porous stones and the test is conducted by applying a series of loads to the specimen. In related materials testing, the J-Ring Test is used for testing self-consolidating concrete, determining its passability and flowability.

Fixed Ring Consolidometer Soil Testing Equipment

Back Pressure Consolidometer allows back pressure saturation and pore pressure measurement of specimens during one-dimensional testing. The Consolidometer is mounted in a conventional Consolidation Load Frame for loading and connected to an HM-350M Master Control Panel for regulation of cell pressures. Permeability can also be determined. The HMA-521 Pore Pressure Transducer with Digital Readout is used with the Master Control Panel to measure real-time pore pressure.

The Back Pressure Consolidometer loads via a stainless steel piston that passes through a top cap with sealed, low-friction linear bearings, stainless steel construction. Ports with connectors allow for application of confining pressures up to 200 psi, and a bottom port monitors pressure and flow rate. The unit tests 2.5x1.0in (63.5x25.4mm) and comes with a sample ring with built-in cutting edge for easy sample preparation. After loading, they are immersed in distilled water to measure the change in height over a 24 hour period. Also included are top and bottom air dried porous stones, flexible tubing and connectors for pressure and pore pressure lines. Sample Rings, Porous Stones and Grade 55 Filter Paper are available separately for additional sample preparation for various specimen sizes. A stainless steel Calibration Disc is optional to measure total system deflection under applied load.

Features:

• Mounts in conventional consolidation device

• Allows back-pressure saturation of samples

• Measures pore pressure, can determine permeability values

For accurate measurement of soil strength, consider using the Pocket Penetrometer for compressive soil strength assessments.

Included Items:

• Back Pressure Consolidometer

• Top and Bottom Porous Stone

Accessories:

• 2.485in Porous Stone, 0.25in Thick, two required

• 2.8in Filter Paper Grade 55 used with Porous Stones to prevent pore blockage from soil fines

• 2.5in Calibration Disc for measuring deflection under load to verify system performance

• 2.5in Cutting Sample Ring has integral cutting edge to aid in sample preparation

Procedure

The procedure for consolidation testing involves several steps, preparing the specimen, assembling the consolidometer and applying the loads. The specimen is prepared by compacting soil into a stainless steel compaction ring, which is then placed in the consolidometer between two porous stones. The consolidometer has an attached acrylic inundation ring, loading pad and collar with lifting knobs. The test is done by applying a series of loads to the specimen using a stainless steel weight and measuring the change in height of the specimen using a dial indicator. The specimen is allowed to consolidate for a specified period, usually 24 hours, before the next load is applied. The test is done in a consolidation load frame which is designed to apply a range of loads to the specimen. The data collected from the test is used to determine the compressibility, strength and potential settlement.