1、Designation: D6574 00 (Reapproved 2011)D6574/D6574M 13Standard Test Method forDetermining the (In-Plane) Hydraulic Transmissivity of aGeosynthetic by Radial Flow1This standard is issued under the fixed designation D6574;D6574/D6574M; the number immediately following the designation indicatesthe year
2、 of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the procedure for determining t
3、he in-plane transmissivity of geosynthetics under varying normalcompressive stresses using a radial flow apparatus. The test is intended to be an index test used primarily for geotextiles, althoughother products composed of geotextiles and geotextile-type materials may be suitable for testing with t
4、his test method.1.2 This test method is based on the assumption that the transmissivity of the geosynthetic is independent of orientation of theflow and is therefore limited to geosynthetics that have similar transmissivity in all directions and should not be used for materialswith oriented flow beh
5、avior.1.3 This test method has been developed specifically for geosynthetics that have transmissivity values on the order of or lessthan 2 104 m2/s. Consider using Test Method D4716 for geosynthetics with transmissivity values higher than 2 104 m2/s.1.4 The values stated in either SI units or inch-p
6、ound units are to be regarded separately as standard. The values given inparentheses are for information only. stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of the other. Combining values from the two systems may result in non-conformance with
7、the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. R
8、eferenced Documents2.1 ASTM Standards:2D4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products(RECPs) for TestingD4439 Terminology for GeosyntheticsD4491 Test Methods for Water Permeability of Geotextiles by PermittivityD4716 Test Method for Determining the (In-plane) Flow R
9、ate per Unit Width and Hydraulic Transmissivity of a GeosyntheticUsing a Constant HeadD5092 Practice for Design and Installation of Ground Water Monitoring Wells3. Terminology3.1 For definitions of terms relating to geosynthetics, refer to Terminology D4439.3.2 Definitions:3.2.1 geosynthetic, na pla
10、nar product manufactured from polymeric material used with soil, rock, earth, or other geotechnicalengineering related material as an integral part of a man-made project, structure, or system. D44393.2.2 geotextile, na permeable geosynthetic comprised solely of textiles. D44393.2.3 gravity flow, nfl
11、ow in a direction parallel to the plane of a geosynthetic driven predominantly by a difference in elevationbetween the inlet and outflow points of a specimen. D44391 This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35
12、.03 on Permeability andFiltration.Current edition approved June 1, 2011July 1, 2013. Published July 2011July 2013. Originally approved in 2000. Last previous edition approved in 20062011 asD6574 00(2006).(2011). DOI: 10.1520/D6574-00R11.10.1520/D6574_D6574M-13.2 For referencedASTM standards, visit t
13、heASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard a
14、n indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is t
15、o be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.3.1 DiscussionThe pressure at the outflow is considered to be atmospheric.3.2.4 head (static), nthe height above a standard datum of the surface
16、 of a column of water (or other liquid) that can besupported by a static pressure at a given point. The static head is the sum of the elevation head and the pressure head. D50923.2.5 hydraulic gradient, i, s (D), nthe loss of hydraulic head per unit distance of flow, dH/dL. D44393.2.5.1 DiscussionTh
17、e gradient is not constant from point to point in the direction of flow in the radial flow test. The gradient (mathematically) varieswith the inverse of the radial distance from the center.3.2.6 hydraulic transmissivity, (L2 T1), nfor a geosynthetic, the volumetric flow rate per unit width of specim
18、en per unitgradient in a direction parallel to the plane of the specimen. D44393.2.6.1 DiscussionTransmissivity is technically applicable only to saturated laminar flow hydraulic conditions.3.2.7 index test, na test procedure, which may contain a known bias but which may be used to establish an orde
19、r for a setof specimens with respect to the property of interest. D44393.2.8 in-plane flow, nfluid flow confined to a direction parallel to the plane of a geosynthetic. D44393.2.9 laminar flow, nflow in which the head loss is proportional to the first power of the velocity. D44393.2.10 normal stress
20、, (FL2), nthe component of applied stress that is perpendicular to the surface on which the force acts.D44393.2.11 turbulent flow, nthat type of flow in which any water particle may move in any direction with respect to any otherparticle and in which the head loss is approximately proportional to th
21、e second power of the velocity. D44393.3 Definitions of Terms Specific to This Standard:3.3.1 steady flow, nhydraulic flow conditions that do not vary with time at any given point.3.3.2 uniform flow, nhydraulic flow conditions where the cross-sectional area and the mean velocity in the direction of
22、floware constant from point to point.4. Summary of Test Method4.1 The transmissivity is determined using a device which transmits the flow of water radially outward from the center of atorus-shaped test specimen. The test method is performed with a constant head under a specific normal stress select
23、ed by the userand may be repeated using several gradients and under increasing normal stresses.4.2 The material property “hydraulic transmissivity” is technically applicable only to the regions of tests where the flow rateis constant with gradient, that is, the laminar region of the tests.4.3 In the
24、 constant head radial flow test, the flow regime is characterized as nonuniform steady flow since the cross-sectionalflow area and the hydraulic gradient vary from point to point along any radial flow line while remaining constant with time.5. Significance and Use5.1 This test method is an index tes
25、t to estimate and compare the in-plane hydraulic transmissivity of one or several candidategeosynthetics under specific gradient and stress conditions.5.2 This test method may be used for acceptance testing of commercial shipments of geosynthetics, but caution is advised sinceinformation about betwe
26、en-laboratory precision is incomplete. Comparative tests as directed in 5.2.1 are advisable.5.2.1 In case of a dispute arising from differences in reported test results when using this procedure for acceptance ofcommercial shipments, the purchaser and the supplier should first confirm that the tests
27、 have been conducted using comparabletest parameters including specimen conditioning, normal stress, hydraulic system gradient, etc. Comparative tests then should beconducted to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended forth
28、e investigation of bias.As a minimum, the two parties should take a group of test specimens that are as homogeneous as possibleand that are formed from a lot of the material in question. The test specimens should be assigned randomly to each laboratory fortesting. The average results from the two la
29、boratories should be compared using the Students t-test for unpaired data and anacceptable probability level chosen by the two parties before testing is begun. If bias is found, either its cause must be found andcorrected or the purchaser and supplier must agree to interpret future test results in l
30、ight of the known bias.D6574/D6574M 1326. Apparatus6.1 A schematic drawing of a typical constant head assembly is shown in Fig. 1. The individual components and accessoriesare as follows:6.1.1 BaseThe bottom section of the apparatus should be constructed of a sturdy metal or plastic plate with a smo
31、oth, flatcontact surface. The center inlet hole shall be 50 mm (2 in).2 in. The outside dimension of the base must match or exceed theoutside diameter of the test specimen. A manometer tap should be located in the sidewall of the inlet opening.6.1.2 Perimeter Containment/Outlet WeirA perimeter ring
32、concentric with the outside diameter of the test specimen withsufficient height to contain the tail water, such that the specimen remains submerged under water at all times during the test. Thecontainment ring should double as the overflow wier, with a beveled edge around the perimeter, with an oute
33、r concentric collectiontrough for collection of the overflow. Alternatively, the containment ring may include a rectangular overflow weir at one locationin the ring that is at least 2.5 cm wide with a beveled overflow plate.6.1.3 Loading PlatenA sturdy circular metal or plastic disc with a smooth, f
34、lat contact surface. The outside diameter of theplaten should be 300 mm (12 in).12 in. The platen/specimen diameter establishes the outside diameter, Ro. The upper platenshould have a spherical chamber of an outside diameter matching the outside diameter of the inlet opening to facilitate collection
35、of any air bubbles that may collect at the specimen inlet. This chamber should be tapped at the apex to allow venting. This tapmay also be connected to a manometer for measurement of the inlet head.6.1.4 Rubber Base and Platen SurfacesA rubber membrane (sheet) material of Buna, Butyl,buna, butyl, or
36、 Neopreneneo-prene rubber 1.52.5 mm (1.5 to 2.5 mm 116 to 332 in.)in. thick with a Shore A hardness of 5080, 50 to 80, cut to match thebase and platen surfaces. The membranes must be adhered to the base and platen surfaces.6.1.5 Loading MechanismAccurate to 61 % of the applied loading and capable of
37、 sustaining a constant normal compressivestress on the torus-shaped specimen within 62 % sustainable over the seating and testing period. The use of static weights, ahydraulic, or a pneumatic ram meeting the above conditions may be considered sufficient for use in this test method.6.1.6 Constant Hea
38、d Device (CHD)A device typically equipped with an inlet, two outlets, and an internal overflow weir orriser. The device should be sized to sustain steady flow conditions under the flow rates involved in the testing.6.1.6.1 Do not use the water level at the CHD to measure the inlet head. The inlet he
39、ad measurement shall be with themanometer tapped directly into the inlet chamber or the platen trap.6.1.7 ManometersA manometer tap shall be installed in the perimeter containment section to measure the tail head directlyand, as detailed in the above sections, within the inlet opening in the base to
40、 measure the inlet head directly. If a rectangular weiris used (see 6.1.2), the tail head tap should be located in the perimeter outflow trough at 90 to the weir location.6.1.7.1 The influence of the meniscus tension within the manometer sight tubes on the head measurements should be checkedby perfo
41、rming a test in accordance with this test method, then ramping the gradient back up to the maximum value (see 10.8 and10.9). The resulting degree of hyteresis in the plot of flow rate versus gradient provides a measure of the sight tube accuracy. Ifthe meniscus effect results in a difference in flow
42、 rate values at a given gradient of more than 5 %, the sight tube accuracy shouldbe improved by increasing the inside diameter of the sight tubes, or by using tubes made of glass instead of plastic, or both.6.1.8 Flowrate Measuring EquipmentEquipment that results in a measurement event accuracy of 6
43、2 % of the associatedflowrate. Typically, the outflow is timed with a stopwatch accurate to 0.1s 0.1 s while being collected in a convenient containerand is then transferred to a 1000 mL Class A graduated cylinder.FIG. 1 A Radial Transmissivity Constant Head Testing DeviceD6574/D6574M 1336.1.9 Diefo
44、r cutting the test specimens, consisting of two concentric circular dies, the outer with a diameter of 300 mm (12in.)12 in. and the inner with a diameter of 50 mm (2 in.).2 in.6.1.10 Thickness Monitoring Device (Optional)In the form of a dial gauge and the like, accurate to 0.2 mm (0.005 in.),0.005
45、in., may be used to measure the change in the thickness of the geosynthetic specimen in the device during the test.6.1.11 Test Waterthe water used for testing must be de-aired and filtered. The dissolved oxygen content should not exceed 6ppm. The filter should have a maximum rated opening size of 1-
46、. The preferred test water temperature is 21 6 2C and shall beadhered to in the event of interlaboratory disputes. For routine testing, maintain the test water at 21 6 5C.7. Sampling7.1 Lot SampleDivide the product into lots and for a lot to be tested take the lot sample as directed in Practice D435
47、4.7.2 Laboratory SampleConsider the units in the lot sample as the units in the laboratory sample. For the laboratory sample,take a swatch 1 m in the machine direction by the roll width.7.3 Test SpecimensRemove three specimens randomly spaced along a diagonal extending across the swatch from eachlab
48、oratory sample.7.3.1 Die cut the torus-shaped test specimens with an outside diameter (Do) of 300 mm (12 in.)12 in. and an inside diameter(Di) of 50 mm (2 in.).2 in.7.3.2 The outside and inside diameters of the cut test specimen should be within 62 % of the dimensions specified.7.3.3 Examine the cut
49、 faces of the test specimen, both inner and outer diameter edges, checking for “pinching” of the fibers dueto the cutting mechanism. Manually separate any pinched areas carefully, restoring the cut edge of the material to the “as received”condition.8. Test Parameter Selection8.1 In the absence of a gradient (or gradients) prescribed by the material specification, select a gradient from the followingvalues: 1.0, 0.50, 0.25, and 0.10.8.2 In the absence of normal compressive stresses prescribed by the material spe
