1、Designation: E2398/E2398M 15Standard Test Method forWater Capture and Media Retention of Geocomposite DrainLayers for Vegetative (Green) Roof Systems1This standard is issued under the fixed designation E2398/E2398M; the number immediately following the designation indicates the yearof original adopt
2、ion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the waterand media retention
3、 of synthetic drains layers used in vegeta-tive (green) roof systems.1.2 This test method is applicable to geocomposite drainlayers that retain water and media in cup-like receptacles ontheir upper surface. Examples include shaped plastic mem-branes and closed-cell plastic foam boards.1.3 This test
4、method does not apply to products manufac-tured from water-absorptive materials.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of th
5、e other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health prac
6、tices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE2114 Terminology for Sustainability Relative to the Perfor-mance of BuildingsE2397 Practice for Determination of Dead Loads and LiveLoa
7、ds Associated with Vegetative (Green) Roof Systems3. Terminology3.1 Definitions:3.1.1 For terms related to building construction, refer toTerminology E631.3.1.2 For terms related to sustainability relative to theperformance of buildings, refer to Terminology E2114.3.2 Definitions of Terms Specific t
8、o This Standard:3.2.1 captured water, nthe quantity of water that is re-tained in the drainage layer of a vegetative (green) roof systemafter new water additions have ceased and that cannot escapethe roof except through evaporation or plant transpiration.3.2.2 coupon, na portion of a material or lab
9、oratorysample from which multiple specimens can be taken fortesting.3.2.3 geocomposite drain layer, na synthetic sheet, mat, orpanel that is specifically designed to convey water horizontallytoward the roof deck drains, gutters, or scuppers.3.2.3.1 DiscussionGeocomposite drainage layers includeabsor
10、ptive drainage mats whose principle function is drainage,but which will also contribute to water retention (see retainedwater). Some geocomposite drainage layers may incorporatereceptacles on their upper surfaces that will capture water (seecaptured water).3.2.4 retained water, nthe quantity of wate
11、r that will beretained for a prolonged period against gravity drainage in avegetative (green) roof system, or in one of its components,after new additions by rainfall or artificial irrigation haveceased.3.2.4.1 DiscussionMost of this water will not becomerunoff but will be used to the plant-mediated
12、 processes ofevapo-transpiration.3.2.5 unit media retention volume, nthe volume, ft3/ft2cm3/cm2, that is required to fill a geocomposite drain layer tothe upper most asperities of the geocomposite drain layer.3.2.6 unit water capture volume, nthe maximum volumeof water, ft3/ft2cm3/cm2, that a geocom
13、posite drain layer canhold at a specified inclination.3.2.6.1 DiscussionFor vegetative (green) roofs systemswhere the geocomposite drain layer will be filled with granulardrainage medium, the actual volume is assumed to be 25 % ofthe measured volume. This assumption will allow a directcomparison bet
14、ween geocomposite sheet drains without, re-gard to the granular drainage media used. In computing the1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.24 onSustainability.Current edition approved June 1,
15、2015. Published July 2015. Originally approvedin 2005. Last previous edition approved in 2011 as E2398 11. DOI: 10.1520/E2398_E2398M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
16、formation, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1actual water capture of a geocomposite sheet drain employed ina specific vegetative (green) roof assembly, the
17、porosity of thegranular drainage medium used must be considered (PracticeE2397).4. Summary of Test Method4.1 This procedure provides a method for measuring thevolume of granular media or water, or both, that geocompositedrain layers can hold. The test involves filling the geocompos-ite drain layers
18、with sand and water to establish the respectivevolumes. Since water capture will be influenced by theinclination of the geocomposite drain layer, the tests areconducted at several inclinations.5. Significance and Use5.1 Determining these performance characteristics of veg-etative (green) roof system
19、s provides information to facilitatethe assessment of related engineering aspects of the facility.Such aspects may include structural design requirements,mechanical engineering and thermal design requirements, andfire and life safety requirements.5.1.1 Accurate information about the water and mediah
20、olding capacity of geocomposite drain layers is essential topredict dead load for vegetative (green) roof systems.5.2 Determining these performance characteristics of veg-etative (green) roof systems provides information to facilitateassessment of the performance of one vegetative (green) roofsystem
21、 relative to one another.5.2.1 Water capture is also useful in assessing irrigationrequirements for vegetative (green) roof designs.5.2.2 Information about the unit media retention volume isrequired to predict the quantity of material that will be requiredto construct a vegetative (green) roof with
22、a specified totalthickness.6. Apparatus6.1 Apparatuscontains the following:6.1.1 Scale, accurate to 0.005 oz 0.14 g,6.1.2 Scoop,6.1.3 Water dropper,6.1.4 4-in. 10-cm wide strip of aluminum or copper sheetmetal,6.1.5 Latex or silicone caulk, and6.1.6 Ruler.7. Conditioning7.1 Cut out a rectangular cou
23、pon of the geocomposite drainlayer to be tested.7.2 The coupon should contain only complete, intact recep-tacles. The coupon should contain a minimum of four recep-tacles and be at least 6 in. 15 cm square.8. Procedure8.1 Weigh the coupon in a dry condition, and record.8.2 With the coupon on a level
24、 surface, fill the receptacleswith water using a dropper. Excise caution not to moisten otherparts of the coupon.8.3 Transfer the coupon to the scale and record the weight ofthe coupon with the filled receptacles.8.4 Using a ruler, measure the distance between the centersof adjacent receptacles alon
25、g the width and length of thecoupon.NOTE 1This measurement methods assumes that the receptacles arearranged in a rectangular pattern8.5 Repeat the test after filling the coupon on inclinedsurfaces. The test should be completed for the followinginclinations:8.5.1 2 degrees (3.5 %),8.5.2 5 degrees (8.
26、7 %),8.5.3 10 degrees (17.6 %), and8.5.4 20 degrees (36.4 %).8.6 Form a fence around the margin of the coupon using themetal strip material. As necessary, seal the edge of the fenceusing latex or silicone caulk.Allow the caulk to cure. Using theruler, measure the inside dimensions of the fence.8.7 W
27、eigh the system and record.8.8 Fill the geocomposite drain layer with coarse sand untilthe uppermost asperities are covered. Weigh and record.8.9 Determined the unit weight, lb/ft3kg/m3, of the coarsesand.9. Calculation of Results9.1 Compute the unit media retention volume as follows:Rm 5 144*Ws/ x*
28、y!in. 2 lb! (1)Rm 5 1 3106*Ws/ x*y! SI!where:Rm = unit media retention volume, ft3/ft2cm3/cm2,Ws = weight of system filled with sand minus weight ofsystem without sand, lb kg,x = width fence, in. cm,y = length fence, in. cm, and = unit weight of sand, lb/ft3kg m3.9.2 Compute the unit water capture v
29、olume as follows:Rw 5 2.31*Ww !/N * X * Y!in. 2 lb! (2)Rw 5 1 3103*Ww ! / N * X * Y! SI!Rf 5 0.25*Rw;where:Rw = unit water capture volume, ft3/ft2cm3/cm2,Rf = unit water capture volume, when in-filled with media,ft3/ft2cm3/cm2,Ww = weight of coupon filled with water minus weight ofcoupon dry, lb kg,
30、N = number of receptacles on the coupon,X = receptacle spacing along the width of the coupon, in.cm, andY = receptacle spacing along the length of the coupon, in.cm.9.3 Conduct all tests in duplicate. If the results of two testsdiffer by more than 5 %, then repeat.E2398/E2398M 15210. Report10.1 Repo
31、rt the following information:10.1.1 Product designation,10.1.2 Size of the coupon tested,10.1.3 Number of receptacles included on the coupon,10.1.4 Unit media retention volume, and10.1.5 Unit water capture volume, both Rw and Rf for thefive inclinations.11. Precision and Bias11.1 PrecisionThe precis
32、ion of the procedure for thesetest methods for measuring the media retention and watercapture capacity of geocomposite drain layers is being deter-mined. Parties interested in participating in interlaboratory testprograms should contact Committee E60.11.2 BiasThe bias for these measurements is undet
33、er-mined because there are no reference values available for thematerials used.12. Keywords12.1 geocomposite drain layers; media retention; vegetative(green) roof; water captureASTM International takes no position respecting the validity of any patent rights asserted in connection with any item ment
34、ionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee
35、and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting
36、 of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO B
37、ox C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 153
