ASTM_D_7741_-_D_7741M_-_11e1.pdf

Designation:D7741/D7741M111Standard Test Method forMeasurement of Apparent Viscosity of Asphalt-Rubber orOther Asphalt Binders by Using a Rotational Hand HeldViscometer1This standard is issued under the fixed designation D7741/D7741M;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.1NOTEThe designation of this standard was changed in 2012 to reflect its combined-units status.1.Scope1.1 The use of high viscosity asphalt binders like Asphalt-Rubber is becoming more common in the United States andworldwide.Specifications such as Specification D6114 note theneed for field control of the apparent viscosity and require theuse of a field production rotational viscometer.The testing ofAsphalt-Rubber Binder for use in Asphalt-Rubber Hot Mixand for Asphalt-Rubber Membrane is necessary to ensureconsistent mix properties that will ensure good performance ofthese materials.Logistics of field applications limits the use ofconventional laboratory controls and testing equipment.Thistest,using a hand held rotational viscometer can be conductedin either the field or laboratory to determine the apparentviscosity of Asphalt-Rubber and other high viscosity bindersfor field production control and to assess the uniformity of thebinder produced or for other related purposes.1.2 Asphalt-Rubber Binder consists of a blend of pavinggrade asphalt cement and crumb rubber as described inSpecification D6114.Other high viscosity asphalt binders mayconsist of asphalts modified with polymer or fiber or both.Testing is performed following the specified reaction time,ifany,within the production process.Control of the raw materi-als is separate from the test.1.3 The values stated in SI units or inch-pound units are tobe regarded separately as standard.The values stated in eachsystem may not be exact equivalents;each system shall be usedindependently of the other.Combining values from the twosystems may result in non-compliance with the standard.1.4 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:2D6114 Specification for Asphalt-Rubber Binder3.Significance and Use3.1 This test is primarily used for field production control ofAsphalt-Rubber(A-R)and other high viscosity binders;how-ever the test can also be used in a laboratory setting.3.2 Ahand held rotational viscometer is used to measure theapparent viscosity of a completed blend of A-R or highviscosity binder.A rotor(spindle),turning at constant speed,isinserted in the liquid binder to be measured.The resistance tomovement of the spindle(torque)caused by the viscosity of thesurrounding liquid is measured using a special mechanism toobtain direct readings in Pas or cP.NOTE1Spindle generally made of stainless steel,although anothermetal such as brass could be used.3.3 The measured apparent viscosity is used to control theproduction of the A-R or other high viscosity binder,to assessthe uniformity of the binder produced or for other relatedpurposes.3.4 As the spindle turns in the A-R or other high viscositybinder,it has a tendency to“drill”into the sample(i.e.,forA-R,the spindle spins the rubber particles out of the measurementarea).Consequently,the apparent viscosity drops to reflect onlythe liquid phase of the high viscosity binder.Therefore,thepeak viscosity measurement value is recorded to reflect theviscosity of the blended material.4.Apparatus4.1 Viscometerhand held rotational type viscometer(seeFig.1).The viscometer shall be equipped with a level bubbleto ensure proper orientation of the viscometer in the sample to1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition approved Dec.1,2011.Published January 2012.Last publishedJanuary 2012 as D774111.DOI:10.1520/D7741_D7741M-11E01.2For 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 States1 be tested.Spindle(rotor)speed typically 62.5 rpm,howevermay vary with different manufacturers.4.2 Spindle(Rotor)Diameter-24 6 1.1 mm.1.0 6 0.05inch;Height-53 6 0.1 mm 2 6.005 inch or equivalent(seeFig.2).4.3 ThermometerDigital with metal jacket probe,1 degreeC 2 degree F precision.4.4 Sample Can4 liter 1 gallon metal can with wire bale.4.5 Visco