ASTM_E_2396_-_E_2396M_-_15.pdf

Designation:E2396/E2396M15Standard Test Method forSaturated Water Permeability of Granular Drainage MediaFalling-Head Method for Vegetative(Green)Roof Systems1This standard is issued under the fixed designation E2396/E2396M;the number immediately following the designation indicates the yearof original adoption 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 a procedure for determining thewater permeability of coarse granular materials used in thedrainage layers of vegetative(green)roof systems.1.2 This test method addresses water permeability under thelow-head conditions that typify horizontal flow in vegetative(green)roof applications.1.3 This test method is suitable for coarse-grained materialswith 100%of the material retained on the U.S.#8 2.25 mmsieve.It is not suitable for finer-grained 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 the 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 practices and to determine theapplicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C29/C29M Test Method for Bulk Density(“Unit Weight”)and Voids in AggregateC130 Specification for Lightweight Aggregates for Concrete(Withdrawn 1954)3E631 Terminology of Building ConstructionsE2114 Terminology for Sustainability Relative to the Perfor-mance of Buildings3.Terminology3.1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 to This Standard:3.2.1 water permeabilitythe coefficient which when mul-tiplied by the hydraulic gradient will yield the apparentvelocity with which water(at 68F)will move through across-section of media.3.2.2 wet densitythe density of coarse granular drainagecourse materials determined after immersion for 24 hours.4.Summary of Test Method4.1 This procedure involves measuring the water permeabil-ity of coarse granular materials under the low-head conditionsthat characterize the environment in vegetative(green)roofsystems.A falling-head technique is used.Incidental to theprocedure is the measurement of the wet density of themedium.5.Significance and Use5.1 This test method addresses performance characteristicsfor vegetative(green)roof systems with respect to the waterpermeability of the drainage media.5.1.1 Water permeability of coarse materials is highly influ-enced by the head conditions under which it is measured.Invegetative(green)roofs,coarse materials are frequently usedto create drainage zones for percolated rainfall.5.1.2 This test method is intended to provide water perme-ability data that is relevant to this design condition that ischaracterized by horizontal flow under low-head.This will alsoallow the performance of granular drainage layers in vegetative(green)roof systems to be compared directly to alternativecomponents,such as geocomposite drain layers.5.2 Determining the performance characteristics of vegeta-tive(green)roof systems provides information to facilitate theassessment of related engineering aspects of the facility.Such1This 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 1,2015.Published July 2015.Originally approvedin 2005.Last previous edition approved in 2011 as E2396 11.DOI:10.1520/E2396_E2396M-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 information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 aspects may include structural design requirements,mechani-cal engineering and thermal design requirements,and fire andlife safety requirements.5.3 Determining the performance characteristics of vegeta-tive(green)roof systems provides information to facilitateassessment of the performance of one vegetative(green)roofsystem relative to another.6.Apparatus6.1 The apparatus consists of nested cylinders constructedfrom stainless steel or plastic:6.1.1 Inner cylinderinner diameter of 3.75 in.9.53 cm,32 in.81.3 cm long