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Publication Number: FHWA-RD-07-052
Date: September 2007
Porous Materials Using a Flexible Wall Permeameter (SS11)
This protocol covers the laboratory measurement of the hydraulic conductivity (also referred to as "coefficient of permeability") of water-saturated porous materials with a flexible wall permeameter. This protocol is based on ASTM D5084-90 (Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter). The test shall be performed in accordance with this standard (ASTM D5084-90), as modified herein. Those sections of the ASTM standard included in this protocol by reference and without modification shall be strictly followed. All other sections of this protocol shall be followed as written herein.
The referenced test method shall be performed on representative subgrade samples from one of the thin-walled tube samples obtained at designated LTPP sampling locations.
1.2 This test method shall be utilized with undisturbed thin-walled tube samples that have hydraulic conductivity less than or equal to 1 x 10-5 m/s (1×10-3 cm/s [2.54×10-3 in/s]).
1.3 The hydraulic conductivity of materials with hydraulic conductivities greater than 1x10-5 m/s may be determined by LTPP Protocol P48.
2.2 LTPP Protocols
P48 Permeability of Unbound Base and Subbase Materials Under Constant Head Using a Rigid Wall Permeameter.
P49 Determination of the Natural Moisture Content of Unbound Base/Subbase and Subgrade.
5.1 Hydraulic System - Method B (Falling Head Test) shall be utilized for this testing.
5.1.2 Add: For the purposes of this protocol, the falling head test shall be performed using a constant tailwater elevation.
6.1.2 The permeant liquid shall be 0.005N CaSO4, which can be obtained for example, by dissolving 6.8 grams (0.24 oz.) of nonhydrated reagent grade CaSO4 in 10 liters (2.6 gallons) of de-aired distilled water.
7.1 The specimens shall have a minimum height equal to the diameter.
7.2 The specimens shall be extruded from the tubes and tested without trimming except for cutting the end surfaces plane and perpendicular to the longitudinal axis of the specimen. Where the sampling operations have caused disturbance of the soil, the disturbed material shall be trimmed.
7.2 Delete the last sentence of Section 7.2. Add: The water content of the trimmings shall be determined in accordance with LTPP Protocol P49.
8.3.3 Saturation of the specimen shall be verified by measuring the B coefficient as indicated in 188.8.131.52.
8.4 Consolidate the specimen to the effective vertical stress of 10 psi (69 kPa).
8.5 Use the falling-head test with constant tail water level (Method B).
8.5.1 Utilize published relationships between soil type and hydraulic conductivity and the table shown in 8.5.1 to obtain an estimate of the specimens's hydraulic conductivity and establish a hydraulic gradient to be used during testing.
8.6 Delete the last two sentences of Section 8.6. Add: The final moisture content of the specimen shall be determined using LTPP Protocol P49. The final mass, height and diameter shall be measured to the appropriate number of digits as shown in Section 10.3.
Record the following on Form T57.
10.1 Sample identification shall include: LTPP Laboratory Identification Code, Region, State, State Code, Experiment Number, SHRP ID, Field Set Number, Sampling Area Number, Layer Number, and Location Number.
10.2 Test identification shall include: LTPP Test Designation, LTPP Protocol Number, Laboratory Test Number, and the Test Date.
10.3 Test Results
10.3.1 Initial mass of soil, in grams, to one decimal place.
10.3.2 Initial specimen height, in inches, to two decimal places.
10.3.3 Initial specimen diameter, in inches, to two decimal places.
10.3.4 Final mass of soil, in grams, to one decimal place.
10.3.5 Final specimen height, in inches, to two decimal places.
10.3.6 Final specimen diameter, in inches, to two decimal places.
10.3.7 The initial water content of the specimen (Wi), as a percentage, to the nearest whole number.
10.3.8 The final water content of the specimen (Wf), as a percentage, to the nearest whole number.
10.3.9 The initial dry density of the specimen (DDi) in lb/ft3 (pcf), to the nearest whole number.
10.3.10 The final dry density of the specimen (DDf), in lb/ft3 (pcf), to the nearest whole number.
10.3.11 The magnitude of the total back pressure (BP), in lb/in2 (psi), to the nearest whole number.
10.3.12 The maximum effective consolidation stress, in lb/in2 (psi), to the nearest whole number. The maximum effective stress exists at the effluent end of the test specimen.
10.3.13 The minimum effective consolidation stress, in lb/in2 (psi), to the nearest whole number. The minimum effective stress exists at the influent end of the test specimen.
10.3.14 The maximum hydraulic gradient (H/L)max used in the test, to the nearest whole number.
10.3.15 The minimum hydraulic gradient (H/L)min used in the test, to the nearest whole number.
10.3.16 The final degree of saturation of the specimen (Sr), as a percentage, to the nearest whole number.
10.3.17 The average hydraulic conductivity (k) for the last four determinations of hydraulic conductivity (obtained as described in 8.5.4), reported with two significant figures, for example, 7.1×10-6 cm/s (1.8×10-5 in/s), and reported in units of cm/s.
10.4 Comments shall include LTPP standard code(s), as shown in Section 4.3 of this Guide and any other notes as needed.
LTPP LABORATORY MATERIAL HANDLING AND TESTING
LABORATORY MATERIAL TEST DATAPERMEABILITY
LAB DATA SHEET T57
LTPP TEST DESIGNATION: SS11/LTPP PROTOCOL P57
LABORATORY PERFORMING TEST: _____________________________________________________________
LABORATORY IDENTIFICATION CODE : ___ ___ ___ ___
REGION: STATE: ____________________________ STATE CODE: __ __
EXPERIMENT NO.: SHRP ID: __ __ __ __
SAMPLED BY: __________________________________________ FIELD SET NO.: ___
DATE SAMPLED: __ __ - __ __ - __ __ __ __ SAMPLING AREA NO.: SA- _____
1. LAYER NUMBER ___
2. LABORATORY TEST NUMBER ___
3. LOCATION NUMBER __ __ __
4. LTPP SAMPLE NUMBER __ __ __ __
5. SPECIMEN PARAMETERS (INITIAL)
(a) MASS, grams __ __ __.__ _ _ _ . _
(b) HEIGHT, inches __ __.__ __
(c) DIAMETER, inches __ __.__ __
6. TEST RESULTS
7. SPECIMEN PARAMETERS (FINAL)
10. TEST DATE __ __-__ __-__ __ __ __
|SUBMITTED BY, DATE||CHECKED AND APPROVED, DATE|
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