Permeability (hydraulic conductivity of soil) is a very important factor in the study of the natural behaviour of soil with respect to water flow. This section includes different soil permeability equipment conforming to ASTM, AASHTO, EN and BS Standards for constant-head and falling-head permeability test methods for road base and subbase soils.
Used for measuring permeability of water through granular soils.
Standards BS 1377:5 EN 17892-11 AASHTO T215 ASTM D2434
Constant Head apparatus
This method describes a procedure for the determination of the permeability of water through granular (cohesionless) soils in a steady-state condition. The procedure is to establish representative values of the coefficient of permeability, k, of granular soils that may occur in natural deposits as placed in embankments, or when used as base courses under pavements. The determination of k was developed under the assumptions of the validity of Darcy’s Law, which states that the coefficient of permeability is the ratio of the flow rate to the hydraulic gradient. In order to limit consolidation influences during testing, this procedure is limited to disturbed granular soils with permeability in range of 1 to 1×10-5.
*PRO-COMPACT closed-loop is an innovative mechanical and electronic control that combines orthogonality of the load, pendulum motion of the head and sinusoidal non-friction forward-reverse carriage movement. This results in an optimally compacted sample that features Planarity Regularity and hOmogeneity (PRO). The combined load/displacement compaction procedure provides at the beginning of the test a controlled displacement compaction, which can grant a flat surface of the compacted slab, followed by a load compaction phase, which can replicate the real compaction on the road surface.
Constant head apparatus kit. Include: constant head permeability cell, 75mm dia., Manometer stand with 3 manometer tubes 6mm dia.with ruler 1152x250x34 mm, Costant level tank assembled on height adjustable panel.
 Models | 77-PV41C05 |
Machine control | – Vertical load and/or displacement control of the roller segment by stepper motor, measured directly by linear transducer to verify in real time the specimen thickness for more accuracy |
Software | – 21” Touchscreen integrated PC |
Max. vertical force | 30 kN |
Load measurement | By two precision load cell |
Compacting device | Roller segment, radius 535 mm |
Back and forth horizontal travel | Adjustable: 300/320 mm |
Trolley speed | Adjustable up to 300 mm/s |
Mould dimensions* | 320 x 260 x 195 mm |
Roller vibration | Yes, adjustable frequency from 10 to 50 Hz (optional) |
Heated foot | Yes (optional) |
Heated base | Yes (optional) |
Electrical supply | 380 V, 50 Hz, 3 ph, or |
Power rating | 3000 W |
*To produce slabs down to 38 mm thickness. Maximum slab thickness varies with bitumen mixes composition.
Used for determining permeability of fine grained soils with intermediate and low permeability.
Standards EN 17892-11 ASTM D5856
The falling head permeability test is used to determine the permeability of fine grained soils with intermediate and low permeability such as silts and clays with permeability in range of 1×10-5 to 1×10-9. This testing method can be applied to an undisturbed sample. The falling head principle can be applied to an undisturbed sample in a sampling tube and to a sample in an oedometer consolidation cell.
This test method covers laboratory measurement of the hydraulic conductivity of laboratory-compacted materials with a rigid-wall, compaction-mold permeameter and may be used with compacted specimens that have a hydraulic conductivity less than or equal to 1 × 10−5 m/s.
For falling head test de-aring water is strictly raccomanded (see Related Products)
Falling head apparatus kit. Include: falling head permeability cell 100 mm internal dia., manometer stand with 3 tubes 6,8,14 mm dia. with quick couplings and anchoring system 1152x250x34 mm, soaking reservoir.
Falling head apparatus kit. Include: compaction mould permeameter, 4″” (101.6mm) dia. conforming to ASTM D5856, manometer stand with 3 tubes 6, 8, 14 mm dia. with connecting valves and anchoring system 1152x250x34 mm.
Shearing motion: Electromechanically driven at 4°
Basic system for both constant or falling head methods for determining the soil permeability.
Standards ASTM D2434
Used for both constant or falling head methods for determining the soil permeability. The apparatus consists of a two section plastic chamber, a plated steel top with gaskets, a plastic funnel reservoir 550 mm max. head with reservoir upright, a 100 cc pipette, and two porous stones 63.5 mm dia. x 12.7 mm thick, 300 micron average pore size.
Combined constant or falling head permeameter
Porous stone 71 mm dia. (pack of 5) for Combined constant or falling head permeameter 38-T0186/A
Used for evaluation erodibility of certain fine-grained soils with high sodium content.
Standards ASTM D4647 BS 1377:5
Certain fine-grained soils with high sodium content are highly erodible by the water flowing through them. During the test the flow of water under a high hydraulic gradient through a cavity in the soil is reproduced. The test apparatus consists of a cylindrical metal container fit one end with water inlet and the other end with an outlet connection, of a standpipe tube with scale and a stand to support the pinhole apparatus.
