ASTM_D_7760_-_12.pdf

Designation:D776012Standard Test Method forMeasurement of Hydraulic Conductivity of Tire DerivedAggregates Using a Rigid Wall Permeameter1This standard is issued under the fixed designation D7760;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers laboratory measurement of thehydraulic conductivity(also referred to as coeffcient of per-meability)of water-saturated tired derived aggregates(TDA)obtained from scrap tires using a rigid-wall permeameter.Thetire materials covered in this method include tire chips,tireshreds,and tire derived aggregate(TDA)as described inPractice D6270 with particle sizes ranging from approximately12 to 305 mm.Whole scrap tires are not included in thisstandard.A clear trend between hydraulic conductivity andshred size has not been established at a given vertical pressurefor shreds 50 mm(1).21.2 A single-or dual-ring permeameter may be used in thetests.A dual-ring permeameter may be preferred over asingle-ring permeameter to take into account and preventshort-circuiting of permeant along the sidewalls of the per-meameter.The effects of sidewall flow is more significant athigh stresses and when the cell diameter is less than 6 times theparticle size(1).1.3 The test method is used under constant head conditions.1.4 Water is used as the permeant with the test method.1.5 Test Method D2434 also can be used for determinationof hydraulic conductivity of TDAs with sizes smaller than 19mm under constant head conditions in a rigid-wall permeame-ter.Method D2434 includes the use of a permeameter with asingle ring.1.6 The standard units for the hydraulic conductivity valuesare the SI units,unless other units are specified.Hydraulicconductivity has traditionally been expressed in cm/s in theU.S.,even though the official SI unit for hydraulic conductivityis m/s.1.7 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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D653 Terminology Relating to Soil,Rock,and ContainedFluidsD2434 Test Method for Permeability of Granular Soils(Constant Head)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4753 Guide for Evaluating,Selecting,and Specifying Bal-ances and Standard Masses for Use in Soil,Rock,andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalDataD6270 Practice for Use of Scrap Tires in Civil EngineeringApplications3.Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard,referto Terminology D653.3.1.2 For definitions of terms related to scrap tires,refer toPractice D6270.3.2 Definitions of Terms Specific to This Standard:3.2.1 hydraulic conductivity,k(also referred to as coeff-cient of permeability or permeability)the rate of discharge ofwater under laminar flow conditions through a unit cross-sectional area of porous medium under a unit hydraulicgradient and standard temperature conditions(20 C).3.2.2 hydraulic gradient,ithe change in total head(headloss,h)per unit distance(L)in the direction of fluid flow,inwhich i=h/L.3.2.3 permeameterthe apparatus(cell)containing the testspecimen in a hydraulic conductivity test.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.14 on Geotechnics ofSustainable Construction.Current edition approved June 1,2012.Published August 2012.DOI:10.1520/D7760122The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Significance and Use4.1 This test method is used to measure one-dimensionalvertical flow of water through initially saturated TDAs underan applied hydraulic gradient.Hydraulic conductivity is re-quired in various civil engineering applications of TDAs.4.2 TDAs are to be tested at a unit weight and under anoverburden pressure representative of field conditions.Datafrom the literature indicate a reduction in hydraulic conductiv-ity with increasing vertical pressure(1).4.3 Use of a dual-ring permeameter is included in this testmethod in addition to a single-ring permeameter.The dual-ringpermeameter allows for