ASTM_D_4957_-_08.pdf

Designation:D495708Standard Test Method forApparent Viscosity of Asphalt Emulsion Residues and Non-Newtonian Bitumens by Vacuum Capillary Viscometer1This standard is issued under the fixed designation D4957;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 describes procedures primarily de-signed to determine the apparent viscosities of residues ob-tained by distilling asphalt emulsions according to Test MethodD6997.It is also recommended for use on non-Newtonianasphalts at any temperature within the capability of theapparatus.This test method is useful in characterizing rheo-logical properties of non-Newtonian bitumens as a function ofshear rate under the conditions of the test method.This test isrun in straight open-end tube viscometers,normally at 60C(140F),but is suitable for use at other temperatures.It isapplicable over the range from 5 to 50 000 Pas(50 to 500 000P).NOTE1The precision for this test method is based on determinationsmade at 60C(140F).1.2 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:2D2171 Test Method for Viscosity of Asphalts by VacuumCapillary ViscometerD6997 Test Method for Distillation of Emulsified AsphaltE1 Specification for ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometers3.Terminology3.1 Definitions:3.1.1 apparent viscositythe determined viscosity obtainedby the test method under description.Viscosity is the resistanceto deformation or internal friction of a liquid expressed as theratio of the shear stress to shear rate,whether this ratio isconstant or not.The unit of viscosity obtained by dividing theshearing stress in N/m2by the rate of shear in reciprocalseconds is called the pascal second(Pas).The English unit ofviscosity is the poise(P)with dimensions of 0.1Ns/m2,(dynes/cm2/s)and is equivalent to 0.1 Pas.3.1.2 Newtonian liquida liquid in which the rate of shearis proportional to the shearing stress.The constant ratio of theshearing stress to rate of shear is the viscosity of the liquid.Ifthe ratio is not constant,the liquid is non-Newtonian.NOTE2A power law fluid is a material in which the relation betweenthe log of the shear stress is linear with the log of the shear rate.The slopeof this relation is called the shear susceptibility,C.If C is less than unity,the material is classified as pseudoplastic and the apparent viscositydecreases with increased stress.If C is greater than one,the material isdilatant and the apparent viscosity increases with stress.If C is unity thematerial shows Newtonian flow.Most real materials show some non-Newtonian behavior and the apparent viscosity,computed as stressdivided by the shear rate,is reported.3.1.3 rheograma rheological diagram which shows howthe apparent viscosity of a material varies with the shear rate.An apparent viscosity at a specific shear rate,normally 1 s1can be estimated from this plot.A typical rheogram with anexample is shown in Fig.1.4.Summary of Test Method4.1 The time is measured for a fixed volume of the liquid tobe drawn up through a straight open-end capillary tube bymeans of vacuum,under closely controlled conditions ofvacuum and temperature.The apparent viscosity in poises iscalculated by multiplying the flow time in seconds by theappropriate viscometer calibration factor or calculated viscom-eter constant.5.Significance and Use5.1 This test method is useful for characterizing the flowbehavior of asphalt emulsion residues and non-Newtonianbitumens.However,since non-Newtonian viscosity valuesdepend on the level of shearing stress,its duration,and theshear history of the material,a non-Newtonian viscosity is not1This 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 Jan.1,2008.Published February 2008.Originallyapproved in 1989.Last previous edition approved in 1995 as D4957 95 which waswithdrawn March 2005 and reinstated in January 2008.DOI:10.1520/D4957-08.2For 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 a unique material property.Instead,it is a parameter which ischaracteristic of the fluid-viscometer syste