1、Designation: D2872 04 D2872 12Standard 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 D2872; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 is intended to measure the effect of heat and air on a moving film of semi-soli
3、d asphaltic materials. Theeffects of this treatment are determined from measurements of the selected properties of the asphalt before and after the test.1.2 The values stated in inch-pound units are to be regarded as the standard.1.3 This standard does not purport to address all of the safety concer
4、ns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D113 Test Method for Ductility of Bituminous
5、 MaterialsD2171 Test Method for Viscosity of Asphalts by Vacuum Capillary ViscometerE1 Specification for ASTM Liquid-in-Glass ThermometersE644 Test Methods for Testing Industrial Resistance ThermometersE1137/E1137M Specification for Industrial Platinum Resistance Thermometers3. Summary of Test Metho
6、d3.1 A moving film of asphaltic material is heated in an oven for 85 min at 325F (163C). The effects of heat and air aredetermined from changes in physical test values as measured before and after the oven treatment. An optional procedure isprovided for determining the change in sample mass.3.2 Prec
7、ision values for this test method have been developed for viscosity at 140F (60C); ductility at 60F (15.6C); and masschange.4. Significance and Use4.1 This test method indicates approximate change in properties of asphalt during conventional hot-mixing at about 302F(150C) as indicated by viscosity a
8、nd other rheological measurements. It yields a residue which approximates the asphalt conditionas incorporated in the pavement. If the mixing temperature differs appreciably from the 302F (150C) level, more or less effecton properties will occur. This test method also can be used to determine mass c
9、hange, which is a measure of asphalt volatility.5. Apparatus5.1 OvenThis shall be a double-walled electrically heated convection-type oven. Its inside dimensions shall be 15 in. (381mm) high, 19 in. (483 mm) wide (including the plenum), and 1712 6 12 in. (445 6 13 mm) deep (with the door closed). Th
10、e doorshall contain a symmetrically located window with dimensions of 12 to 13 in. (305 to 330 mm) wide by 8 to 9 in. (203 to 229mm) high. The window shall contain two sheets of heat-resistant glass separated by an air space. The window should permit anunobstructed view of the interior of the oven.
11、The top of the upper heating element shall be 1 6 18 in. (25 6 3 mm) below theoven floor.5.1.1 The oven shall be vented at the top and bottom. The bottom vents shall be located symmetrically to supply incoming airaround the heating elements. They shall have an open area of 2.31 6 0.11 in.2 (15.0 6 0
12、.7 cm2). The top vents shall besymmetrically arranged in the upper part of the oven and have 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 side walls and ceiling. The air space shall be 112 in. (38.1 mm) deep fromthe walls and ceiling. At a mi
13、dpoint in the width of the oven, and 6 in. (152.4 mm) from the face of the circular metal carriageto 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 an externallyCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
14、ohocken, PA 19428-2959. United States1mounted motor. The squirrel cage fan shall be set so that the fan turns in an opposite direction to its vanes. The air flowcharacteristics of the fan-plenum system shall be suction from the floor of the oven through the wall plenums and exhaust of theair through
15、 the fan. Fig. 1 and Fig. 2 show details of this plenum system.5.1.3 The oven shall be equipped with a proportional control thermostat capable of maintaining a temperature of 325F (163C)to within 61.0F (60.5C). The sensing element of the thermostat may be placed at any location that enables the oven
16、 to maintaintemperature control as specified by this standard.5.1.4 The thermometer shall be hung or affixed to a mounting in the ceiling which is 2 in. (50.8 mm) from the right side of theoven at a midpoint in the depth of the oven. The thermometer shall hang down into the oven so that the bulb of
17、the thermometeris within 1 in. of an imaginary line level with the shaft of the circular metal carriage. The heating controls shall be capable ofbringing the fully loaded oven back to the test temperature within a 10-min period after insertion of the samples in a preheatedoven.5.1.5 The oven shall b
18、e provided with a 12-in. (304.8-mm) diameter, vertical circular carriage (see Fig. 2 for details). Thiscarriage shall be provided with suitable openings and clips for firmly holding eight glass containers in a horizontal position (seeFig. 3). The vertical carriage shall be mechanically driven throug
19、h a 34-in. (19-mm) diameter shaft at a speed of 15 6 0.2 r/min.1 This test method is under the jurisdiction of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.46 on Durabilityand Distillation Tests.Current edition approved June 1, 2004Aug. 1, 2012
20、. Published September 2004August 2012. Originally approved in 1970. Last previous edition approved in 19972004as D2872 97.D2872 04. DOI: 10.1520/D2872122 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM
21、Standardsvolume information, refer to the standards Document Summary page on the ASTM website.FIG. 1 Schematic of Air Flow Front ViewD2872 122FIG. 2 Circular Metal CarriageFIG. 3 Sample BottleD2872 1235.1.6 The oven shall be equipped with an air jet positioned to blow heated air into each bottle at
22、its lowest point of travel. Theair jet shall have an outlet orifice 0.04 in. (1.016 mm) in diameter (No. 60 drill) connected to a 25-ft (7.6-m) length of 516-in.(8-mm) outside diameter refrigeration copper tubing. This tubing shall be coiled to lie flat on the bottom of the oven and lead toa source
23、of fresh, dried, dust-free regulated air.NOTE 1Activated silica gel treated with an indicator is a satisfactory desiccant for the dried air.5.2 FlowmeterThe flowmeter may be any suitable type capable of accurately measuring the airflow at a rate of 4000 mL/min.The flowmeter shall be located downstre
24、am of all regulating devices and upstream of the copper coil. The flowmeter shall bepositioned so it is maintained at approximately room temperature. The airflow shall be calibrated periodically using a wet-testmeter or other displacement method. This calibration shall be based on airflow exiting th
25、e air jet and shall be conducted with theoven off and at room temperature.5.3 ThermometerThis shall be an ASTM Thermometer conforming to the requirements for Thermometer 13C as prescribedin Specification E1. This thermometer shall be used to make all temperature measurements required by this test me
26、thod. In orderto reduce the risks associated with thermometer breakage, the thermometer may be fully or partially encapsulated in an opticallytransparent polymer sheath having a maximum thickness of 0.01 in. (0.25 mm). If a sheath is used, it shall be installed such thatthere is substantial mechanic
27、al contact with the thermometer. The thermometer shall be recalibrated after installation of a sheath.5.3.1 The test thermometer may be replaced with an electronic temperature measurement system, provided the followingrequirements are met:5.3.1.1 The electronic temperature sensor shall be a 3 or 4 w
28、ire, Grade A Platinum Resistance Thermometer (PRT) substantiallyconforming to the requirements of Specification E1137/E1137M. The temperature sensor shall be mounted in the same positionand orientation as the test thermometer it replaces.5.3.1.2 The electronic sensor shall have a thermal response ti
29、me that differs by no more than 30% from the thermal responsetime of the designated test thermometer. Thermal response shall be defined as the time required to achieve a 95% response to atemperature step change, starting in air at ambient temperature, and ending in air at any convenient and constant
30、 temperature inthe range of 165170C. Guidance for determining thermal response time is given in Test Methods E644.5.3.1.3 The electronic measurement circuitry shall include a digital display having a resolution of 0.1C or better.5.3.1.4 The electronic temperature sensor and electronic measurement ci
31、rcuitry shall be calibrated and verified as a unit.Calibration and verification shall be NIST traceable. The temperature measurement system shall be calibrated prior to being placedinto service and verified annually thereafter. Guidance for performing the calibration is given in Test Methods E644.5.
32、3.1.5 Verification shall be conducted with the test oven equilibrated at normal operating temperature while the verificationsensor is in mechanical contact with the normal test sensor. If the difference between the verification sensor and the normal testsensor exceeds 0.2C, the verification will be
33、regarded as having failed, and the temperature measurement system shall berecalibrated.5.4 ContainerThe container in which the sample is to be tested shall be of clear, transparent, heat-resistant glass conformingto the dimensions shown in Fig. 3.5.5 Cooling RackA wire or sheet metal rack, construct
34、ed of stainless steel or aluminum, which allows the sample containersto cool in a horizontal position, with each container in the same horizontal plane. The rack shall be constructed in a way that allowsair to flow freely around each container with at least 1 in. (2.5 cm) clearance between container
35、s and at least 1 in. (2.5 cm) clearancebetween the containers and any solid surface.6.1 Determine the preheat time for the oven in accordance with either 6.1.1 or 6.1.2. If Section 6.1.1 is used, this determinationmust be made for each oven, and shall be repeated at least annually or whenever enviro
36、nmental conditions or the test locationchange. If Section 6.1.2 is used, no annual determination is necessary.6.1.1 Adjust the oven control thermostat to the setting that will be used during the test. Select this setting so that when the ovenis fully loaded and the air is on, the oven will equilibra
37、te at 325 6 1F (163 6 0.5C), as indicated by the test thermometer. Turnthe oven on and simultaneously record the start time to the nearest whole minute. Determine and record the temperature of the ovenat 15-minute intervals. Continue this process until the oven reaches thermal equilibrium. Thermal e
38、quilibrium is considered to bethe time when the oven temperature does not vary by more than 1F (0.5C) between two consecutive readings. The oven preheattime is the time that it takes to reach thermal equilibrium plus an additional 30 minutes.6.1.2 In lieu of completing the steps described in Section
39、 6.1.1, a minimum preheat time of 4 hours may be used.7. Preparation of Oven7.1 Position the air outlet orifice so that it is 14 in. 6 18 in. (6 mm 6 3 mm) from the opening of the glass container. The orificeshall also be so positioned that the jet blows horizontally into the central arc of the open
40、ing of the circling glass container.7.2 Position the thermometer specified in 5.3 so that the end of the bulb of the thermometer is within 1 in. (25.4 mm) of animaginary line level with the center of the shaft holding the revolving carriage.7.3 Level the oven so that the horizontal axes of the glass
41、 containers when in position in the carriage are level to within 6 1.0.D2872 1247.4 Start the fan. The fan shall remain on whenever the oven heater is on and the oven door is closed. This standard permits(but does not require) the fan to be stopped when the oven door is opened. Stopping the fan may
42、be accomplished manually, withan electronic door interlock, or through other means.7.5 Preheat the oven for a minimum of 16 h the preheat time determined in Section 6 or longer prior to testing with the controlthermostat adjusted to the setting that will be used during the test. This setting shall b
43、e selected such Select this setting so that whenthe oven is fully loaded and the air is on, the oven will equilibrate at 325 6 1F (163 6 0.5C), as indicated by the testthermometer.NOTE 2Because the presence of sample containers affects the temperature distribution in the oven, containers should be p
44、resent in the oven whenthe thermostat setting is determined. The use of empty containers is acceptable for this purpose.8. Procedure8.1 The sample as received shall be free of water. Heat the sample in its container with a loosely fitted cover in an oven notto exceed 302F (150C) for the minimum time
45、 necessary to ensure that the sample is completely fluid. Manually stir the samplebut avoid incorporating air bubbles.8.2 Pour 35 6 0.5 g of the sample into each of the required glass containers, providing sufficient material for characterizing testswhich are to be run on the residue.8.3 Immediately
46、 after pouring the sample into a glass container, turn the container to a horizontal position. Rotate the containerslowly for at least one full rotation, and attempt to pre-coat its cylindrical surface. It is not necessary to pre-coat the open end ofthe container, and care should be taken to prevent
47、 the sample from flowing out of the container during this step. Place the containerhorizontally in a clean cooling rack that is maintained in a draft-free, room-temperature location away from ovens and othersources of heat.NOTE 3Complete pre-coating may not be possible for certain binders.NOTE 4For
48、maximum precision in determining mass change, the cooling rack should be in a location that is the same temperature and humidity asthe balance used for measuring the mass of the containers.NOTE 5Static electricity may cause unstable mass measurements, due in part to the characteristics of the glass
49、sample containers. This problem canbe minimized by mounting a passive ion source inside the balance draft shield.38.3.1 Allow the glass sample containers to cool in the cooling rack for a minimum of 60 min, and a maximum of 180 min.8.3.2 When mass change is being determined, use two separate containers for this determination. After cooling, determine themass of these containers using an analytical balance having a resolution of 0.001 g or better. Separately place each containervertically on the balance, and record the mass to t
