ASTM_D_7227_-_D_7227M_-_17.pdf

Designation:D7227/D7227M17Standard Practice forRapid Drying of Compacted Asphalt Mixture SpecimensUsing Vacuum Drying Apparatus1This standard is issued under the fixed designation D7227/D7227M;the number immediately following the designation indicates theyear 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 practice covers the process of drying compactedasphalt mixture specimens using vacuum drying apparatus.1.2 The specimens dried by this practice remain at roomtemperature,which helps in maintaining specimen integrityduring the drying process.1.3 This practice can be used for compacted cylindrical andcubical laboratory and field asphalt mixture specimens.1.4 This practice can also be used for drying other construc-tion materials such as concrete,soils,aggregates,and looseasphalt mixtures.Use the manufacturers recommendations fordrying other construction materials.1.5 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 equivalent;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in nonconformancewith the standard.1.6 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.1.7 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 requirements prior to use.1.8 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 MaterialsD5361 Practice for Sampling Compacted Bituminous Mix-tures for Laboratory Testing3.Terminology3.1 For definitions of terms used in this standard,refer toTerminology D8.4.Significance and Use4.1 Specimen dry weight is a critical measure in determi-nation of accurate density and many other tests in the construc-tion and raw materials industries.Drying specimens at roomtemperature is required for some tests and provides an advan-tage for other tests to ensure the integrity and to preserve thecharacteristics of specimens.4.2 This practice covers drying compacted asphalt mixturespecimens in a vacuum chamber that is capable of keeping thespecimen at close to room temperature.A vacuum pumpreduces the pressure inside the chamber,thus allowing water toevaporate at low temperature.Since the specimen naturallycools during the evaporation process,making water harder toevaporate,it is important to have proper temperature controlsin the chamber to ensure the specimen remains at close to roomtemperature.Automatic controls within the unit allow thespecimen to remain at close to room temperature by periodi-cally allowing a flow of warm air to enter the vacuum chamber.Cycling between vacuum and airflow conditions allows thespecimen to dry in a short period of time.Completely saturatedspecimens with over 30 g 0.07 lb of retained water can bedried in about 30 min.For most field cores that are notcompletely saturated,the drying time is generally less than15 min.1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.21 onSpecific Gravity and Density of Asphalt Mixtures.Current edition approved June 1,2017.Published June 2017.Originallyapproved in 2006.Last previous edition approved in 2011 as D7227/D7227M 111.DOI:10.1520/D7227_D7227M-17.2For 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.1 NOTE1Cycle time(period)can depend on the material composition.Each cycle involves an alternating period