1、Designation: D 2872 04Standard Test Method forEffect of Heat and Air on a Moving Film of Asphalt (RollingThin-Film Oven Test)1This standard is issued under the fixed designation D 2872; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is intended to measure the effect ofheat and air on a moving film of semi-solid aspha
3、ltic materials.The effects of this treatment are determined from measure-ments of the selected properties of the asphalt before and afterthe test.1.2 The values stated in inch-pound units are to be regardedas the standard.1.3 This standard does not purport to address all of thesafety concerns, if an
4、y, 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:2D 113 Test Method for Ductility of Bituminous Mate
5、rialsD 2171 Test Method for Viscosity of Asphalts by VacuumCapillary ViscometerE 1 Specification for ASTM ThermometersE 644 Test Methods for Testing Industrial Resistance Ther-mometersE 1137 Specification for Industrial Platinum ResistanceThermometers3. Summary of Test Method3.1 A moving film of asp
6、haltic material is heated in an ovenfor 85 min at 325F (163C). The effects of heat and air aredetermined from changes in physical test values as measuredbefore and after the oven treatment. An optional procedure isprovided for determining the change in sample mass.3.2 Precision values for this test
7、method have been devel-oped for viscosity at 140F (60C); ductility at 60F (15.6C);and mass change.4. Significance and Use4.1 This test method indicates approximate change in prop-erties of asphalt during conventional hot-mixing at about302F (150C) as indicated by viscosity and other rheologicalmeasu
8、rements. It yields a residue which approximates theasphalt condition as incorporated in the pavement. If themixing temperature differs appreciably from the 302F(150C) level, more or less effect on properties will occur. Thistest method also can be used to determine mass change, whichis a measure of
9、asphalt volatility.5. Apparatus5.1 OvenThis shall be a double-walled electrically heatedconvection-type oven. Its inside dimensions shall be 15 in.(381 mm) high, 19 in. (483 mm) wide (including the plenum),and 1712 612 in. (445 6 13 mm) deep (with the door closed).The door shall contain a symmetrica
10、lly located window withdimensions of 12 to 13 in. (305 to 330 mm) wide by 8 to 9 in.(203 to 229 mm) high. The window shall contain two sheets ofheat-resistant glass separated by an air space. The windowshould permit an unobstructed view of the interior of the oven.The top of the upper heating elemen
11、t shall be 1 618 in. (25 63 mm) below the oven floor.5.1.1 The oven shall be vented at the top and bottom. Thebottom vents shall be located symmetrically to supply incom-ing air around the heating elements. They shall have an openarea of 2.31 6 0.11 in.2(15.0 6 0.7 cm2). The top vents shallbe symmet
12、rically arranged in the upper part of the oven andhave an open area of 1.45 6 0.07 in.2(9.3 6 0.45 cm2).5.1.2 The oven shall have an air plenum covering the sidewalls and ceiling. The air space shall be 112 in. (38.1 mm) deepfrom the walls and ceiling. At a midpoint in the width of theoven, and 6 in
13、. (152.4 mm) from the face of the circular metalcarriage to its axis, a squirrel cage-type fan 514 in. (133 mm)OD by 278 in. (73 mm) wide shall be turned at 1725 rpm by anexternally mounted motor. The squirrel cage fan shall be set sothat the fan turns in an opposite direction to its vanes. The airf
14、low characteristics of the fan-plenum system shall be suctionfrom the floor of the oven through the wall plenums andexhaust of the air through the fan. Fig. 1 and Fig. 2 showdetails of this plenum system.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials an
15、d is the direct responsibility of Subcommittee D04.46 onDurability and Distillation Tests.Current edition approved June 1, 2004. Published September 2004. Originallyapproved in 1970. Last previous edition approved in 1997 as D 2872 97.2For referenced ASTM standards, visit the ASTM website, www.astm.
16、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.3 The o
17、ven shall be equipped with a proportionalcontrol thermostat capable of maintaining a temperature of325F (163C) to within 61.0F (60.5C). The sensingelement of the thermostat may be placed at any location thatenables the oven to maintain temperature control as specifiedby this standard.5.1.4 The therm
18、ometer shall be hung or affixed to a mount-ing in the ceiling which is 2 in. (50.8 mm) from the right sideof the oven at a midpoint in the depth of the oven. Thethermometer shall hang down into the oven so that the bulb ofthe thermometer is within 1 in. of an imaginary line level withthe shaft of th
19、e circular metal carriage. The heating controlsshall be capable of bringing the fully loaded oven back to thetest temperature within a 10-min period after insertion of thesamples in a preheated oven.5.1.5 The oven shall be provided with a 12-in. (304.8-mm)diameter, vertical circular carriage (see Fi
20、g. 2 for details). Thiscarriage shall be provided with suitable openings and clips forfirmly holding eight glass containers in a horizontal position(see Fig. 3). The vertical carriage shall be mechanically driventhrough a34-in. (19-mm) diameter shaft at a speed of 15 6 0.2r/min.5.1.6 The oven shall
21、be equipped with an air jet positionedto blow heated air into each bottle at its lowest point of travel.The air jet shall have an outlet orifice 0.04 in. (1.016 mm) indiameter (No. 60 drill) connected to a 25-ft (7.6-m) length of516-in. (8-mm) outside diameter refrigeration copper tubing.This tubing
22、 shall be coiled to lie flat on the bottom of the ovenand lead to a source of fresh, dried, dust-free regulated air.NOTE 1Activated silica gel treated with an indicator is a satisfactorydesiccant for the dried air.5.2 FlowmeterThe flowmeter may be any suitable typecapable of accurately measuring the
23、 airflow at a rate of 4000mL/min. The flowmeter shall be located downstream of allregulating devices and upstream of the copper coil. Theflowmeter shall be positioned so it is maintained at approxi-mately room temperature. The airflow shall be calibratedperiodically using a wet-test meter or other d
24、isplacementFIG. 1 Schematic of Air Flow Front ViewD2872042method. This calibration shall be based on airflow exiting theair jet and shall be conducted with the oven off and at roomtemperature.5.3 ThermometerThis shall be an ASTM Thermometerconforming to the requirements for Thermometer 13C asprescri
25、bed in Specification E 1. This thermometer shall be usedto make all temperature measurements required by this testmethod. In order to reduce the risks associated with thermom-eter breakage, the thermometer may be fully or partiallyencapsulated in an optically transparent polymer sheath havinga maxim
26、um thickness of 0.01 in. (0.25 mm). If a sheath is used,it shall be installed such that there is substantial mechanicalcontact with the thermometer. The thermometer shall berecalibrated after installation of a sheath.5.3.1 The test thermometer may be replaced with an elec-tronic temperature measurem
27、ent system, provided the follow-ing requirements are met:5.3.1.1 The electronic temperature sensor shall bea3or4wire, Grade A Platinum Resistance Thermometer (PRT) sub-stantially conforming to the requirements of Specification E1137. The temperature sensor shall be mounted in the sameposition and or
28、ientation as the test thermometer it replaces.5.3.1.2 The electronic sensor shall have a thermal responsetime that differs by no more than 30% from the thermalresponse time of the designated test thermometer. Thermalresponse shall be defined as the time required to achieve a 95%response to a tempera
29、ture step change, starting in air at ambienttemperature, and ending in air at any convenient and constantFIG. 2 Circular Metal CarriageFIG. 3 Sample BottleD2872043temperature in the range of 165170C. Guidance for deter-mining thermal response time is given in Test Methods E 644.5.3.1.3 The electroni
30、c measurement circuitry shall include adigital display having a resolution of 0.1C or better.5.3.1.4 The electronic temperature sensor and electronicmeasurement circuitry shall be calibrated and verified as a unit.Calibration and verification shall be NIST traceable. Thetemperature measurement syste
31、m shall be calibrated prior tobeing placed into service and verified annually thereafter.Guidance for performing the calibration is given in TestMethods E 644.5.3.1.5 Verification shall be conducted with the test ovenequilibrated at normal operating temperature while the verifi-cation sensor is in m
32、echanical contact with the normal testsensor. If the difference between the verification sensor and thenormal test sensor exceeds 0.2C, the verification will beregarded as having failed, and the temperature measurementsystem shall be recalibrated.5.4 ContainerThe container in which the sample is to
33、betested shall be of clear, transparent, heat-resistant glass con-forming to the dimensions shown in Fig. 3.5.5 Cooling RackA wire or sheet metal rack, constructedof stainless steel or aluminum, which allows the samplecontainers to cool in a horizontal position, with each containerin the same horizo
34、ntal plane. The rack shall be constructed ina way that allows air to flow freely around each container withat least 1 in. (2.5 cm) clearance between containers and at least1 in. (2.5 cm) clearance between the containers and any solidsurface.6. Preparation of Oven6.1 Position the air outlet orifice s
35、o that it is14 in. 618 in.(6 mm 6 3 mm) from the opening of the glass container. Theorifice shall also be so positioned that the jet blows horizontallyinto the central arc of the opening of the circling glasscontainer.6.2 Position the thermometer specified in 5.3 so that the endof the bulb of the th
36、ermometer is within 1 in. (25.4 mm) of animaginary line level with the center of the shaft holding therevolving carriage.6.3 Level the oven so that the horizontal axes of the glasscontainers when in position in the carriage are level to within6 1.0.6.4 Start the fan. The fan shall remain on whenever
37、 the ovenheater is on and the oven door is closed. This standard permits(but does not require) the fan to be stopped when the oven dooris opened. Stopping the fan may be accomplished manually,with an electronic door interlock, or through other means.6.5 Preheat the oven for a minimum of 16 h prior t
38、o testingwith the control thermostat adjusted to the setting that will beused during the test. This setting shall be selected such thatwhen the oven is fully loaded and the air is on, the oven willequilibrate at 325 6 1F (163 6 0.5C), as indicated by the testthermometer.NOTE 2Because the presence of
39、 sample containers affects the tem-perature distribution in the oven, containers should be present in the ovenwhen the thermostat setting is determined. The use of empty containers isacceptable for this purpose.7. Procedure7.1 The sample as received shall be free of water. Heat thesample in its cont
40、ainer with a loosely fitted cover in an ovennot to exceed 302F (150C) for the minimum time necessaryto ensure that the sample is completely fluid. Manually stir thesample but avoid incorporating air bubbles.7.2 Pour 35 6 0.5 g of the sample into each of the requiredglass containers, providing suffic
41、ient material for characteriz-ing tests which are to be run on the residue.7.3 Immediately after pouring the sample into a glasscontainer, turn the container to a horizontal position. Rotate thecontainer slowly for at least one full rotation, and attempt topre-coat its cylindrical surface. It is not
42、 necessary to pre-coatthe open end of the container, and care should be taken toprevent the sample from flowing out of the container duringthis step. Place the container horizontally in a clean coolingrack that is maintained in a draft-free, room-temperaturelocation away from ovens and other sources
43、 of heat.NOTE 3Complete pre-coating may not be possible for certain binders.NOTE 4For maximum precision in determining mass change, thecooling rack should be in a location that is the same temperature andhumidity as the balance used for measuring the mass of the containers.NOTE 5Static electricity m
44、ay cause unstable mass measurements, duein part to the characteristics of the glass sample containers. This problemcan be minimized by mounting a passive ion source inside the balancedraft shield.37.3.1 Allow the glass sample containers to cool in thecooling rack for a minimum of 60 min, and a maxim
45、um of 180min.7.3.2 When mass change is being determined, use twoseparate containers for this determination. After cooling, de-termine the mass of these containers using an analyticalbalance having a resolution of 0.001 g or better. Separatelyplace each container vertically on the balance, and record
46、 themass to the full resolution of the balance.7.4 With the oven at operating temperature and the airflowset at 4000 6 200 mL/min, arrange the containers holding theasphalt in the carriage so that the carriage is balanced. Fill anyunused spaces in the carriage with empty containers. Close thedoor an
47、d rotate the carriage assembly at a rate of 15 6 0.2r/min. Maintain the samples in the oven with the air flowingand the carriage rotating for 85 min. The test temperature of325 6 lF (163 6 0.5C) shall be reached within the first 10min; otherwise, discontinue the test.7.5 At the conclusion of the tes
48、ting period, remove anysamples for mass change determination and place them hori-zontally in the cooling rack. Then, remove each remainingglass sample container, one at a time, and transfer its contentsto a collection container having a capacity at least 30 % greaterthan the total expected volume of
49、 residue. This transfer shall beaccomplished by first pouring out any residue that will flowfreely from the glass sample container and then scraping out asmuch of the remaining residue as practical. While the residueis being removed from each sample container, the oven doorshall remain closed, with the heater power on, the air on, and3One such ion source is available as model 2U500 from NRD Inc., 2937 AltBoulevard North, Grand Island NY 140721292.D2872044the remaining samples rotating in the carriage. The finalcontainer shall be removed
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