ASTM_D_6926_-_20.pdf

Designation:D692620Standard Practice forPreparation of Asphalt Mixture Specimens Using MarshallApparatus1This standard is issued under the fixed designation D6926;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 practice covers preparation and compaction of 4 in.(101.6 mm)diameter by nominal 2.5 in.(63.5 mm)highcylindrical asphalt paving mixture specimens.This practice isintended for use with laboratory and plant-produced asphaltmixtures with aggregate up to 1 in.(25.4 mm)maximum sizeand for recompaction of asphalt paving mixture samples.NOTE1Historically,35,50,and 75 blows per face has been practicedfor this test.NOTE2Manufacturers do not recommend applying an excessivenumber of blows per face of a sample.This practice has been known tocause fatigue and damage to machine components.1.2 There are three types of Marshall compaction apparatusin use.The following types of hammer arrangements areincluded in this practice:1.2.1 Manually held hammer handle(Type 1)is attached toa flat compaction foot through a spring-loaded swivel and ishand operated(see 5.3.1)(original standard developed by theUnited States Army Corps of Engineers).1.2.2 Hammer handle restrained laterally(fixed)but notvertically(Type 2),attached to a flat compaction foot througha spring-loaded swivel and is either mechanically or handoperated(see 5.3.2).There may or may not be a constantsurcharge on top of the hammer handle.Mechanical hammers(Type 2)are available that operate at a range of 55 to 68 blowsper minute.1.2.3 Hammer handle restrained laterally(fixed)with orwithout constant surcharge on top of hammer,is attached to aslanted compaction foot on a rotating mold base(Type 3),andis mechanically operated(see 5.3.3).This method must be usedas a referee method.1.3 Although the mass and height of mass drop for eachapparatus are the same,density achieved in compacted speci-mens with the same number of blows will be different.It is upto the owner or specifier to establish the specific requirednumber of blows to be used for compaction of the specimen inrelation to the field.1.4 UnitsThe values stated in inch-pound units are to beregarded as standard.The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.5 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the standard.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D8 Terminology Relating to Materials for Roads and Pave-mentsD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD4402/D4402M Test Method for Viscosity Determination ofAsphalt at Elevated Temperatures Using a RotationalViscometerD6927 Test Method for Marshall Stability and Flow ofAsphalt MixturesE1 Specification for ASTM Liquid-in-Glass ThermometersE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE77 Test Method for Inspection and Verification of Ther-mometersE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.20 onMechanical Tests of Asphalt Mixtures.Current edition approved Jan.1,2020.Published January 2020.Originallyapproved in 2004.Last previous edition approved in 2016 as D6926 16.DOI:10.1520/D6926-20.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice,refer toTerminology D8.3.2 Definitions of Terms Specific to This Standard:3.2.1 lab mix lab compacted(LMLC)asphalt mixture,nasphalt mix samples that are prepared in the