1、Designation: D 1754 97 (Reapproved 2002)Standard Test Method forEffects of Heat and Air on Asphaltic Materials (Thin-FilmOven Test)1This standard is issued under the fixed designation D 1754; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 covers the determination of the effectsof heat and air on a film of semisolid a
3、sphaltic materials. Theeffects of this treatment are determined from measurements ofselected asphalt properties before and after the test.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated wi
4、th 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:D 5 Test Method for Penetration of Bituminous Materials2D 113 Test
5、Method for Ductility of Bituminous Materials2D 2170 Test Method for Kinematic Viscosity of Asphalts(Bitumens)2D 2171 Test Method for Viscosity of Asphalts by VacuumCapillary Viscometer2E 1 Specification for ASTM Thermometers3E 145 Specification for Gravity-Convection and Forced-Ventilation Ovens43.
6、Summary of Test Method3.1 A film of asphaltic material is heated in an oven for 5 hat 163C (325F). The effects of heat and air are determinedfrom changes incurred in physical properties measured beforeand after the oven treatment. An optional procedure is providedfor determining the change in sample
7、 mass.3.2 Precision values for the method have been developed forviscosity, viscosity change, penetration change, mass change,and ductility.4. Significance and Use4.1 This method indicates approximate change in propertiesof asphalt during conventional hot-mixing at about 150C(302F) as indicated by v
8、iscosity, penetration, or ductilitymeasurements. It yields a residue which approximates theasphalt condition as incorporated in the pavement. If themixing temperature differs appreciably from the 150C(302F) level, more or less effect on properties will occur.5. Apparatus5.1 OvenThe oven shall be ele
9、ctrically heated and shallconform to the performance requirements of SpecificationE 145, Type IB (Gravity-Convection), for operating tempera-tures up to 180C (356F). During the tests for compliance toSpecification E 145 requirements, the oven shelf, properlycentered as described in 5.1.2 shall be in
10、 place and rotating.5.1.1 ConstructionThe oven shall be rectangular, andeach interior dimension (exclusive of space occupied by theheating element) shall be a minimum of 330 mm (13 in.) anda maximum of 535 mm (21 in.). The oven shall have, in front,a tightly fitted hinged door, which shall provide a
11、 clear openingsubstantially the same as the interior height and width of theoven. The door may contain a window with dimensions of atleast 100 by 100 mm (4 by 4 in.) and with two sheets of glassseparated by an air space, through which a vertical thermom-eter, located as specified in 5.2, may be read
12、 without openingthe door; or the oven may be provided with an inner glass door,through which the thermometer may be observed on openingthe outer door momentarily. The oven shall be adequatelyventilated by convection currents of air and for this purposeshall be provided with openings for the entrance
13、 of air and forthe exit of heated air and vapors. Openings may be of any sizeand arrangement provided the requirements of SpecificationE 145, Type IB, are met.5.1.2 Rotating ShelfThe oven shall be provided with asingle metal circular shelf having a minimum diameter of 250mm (9.8 in.) and a maximum d
14、iameter of 450 mm (18 in.). Theshelf construction shall be such that it provides a flat surfacefor support of the containers without blocking all air circulationthrough the shelf when the containers are in place. The shelfshall be suspended by a vertical shaft and centered with respectto the horizon
15、tal interior dimensions of the oven and shall be1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.46 onDurability and Distillation Test.Current edition approved Aug. 10, 1997. Published February 1998. Or
16、iginallypublished as D 1754 60 T. Last previous edition D 1754 94.2Annual Book of ASTM Standards, Vol 04.03.3Annual Book of ASTM Standards, Vol 14.03.4Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
17、States.provided with a mechanical means of rotating it at the rate of5.5 6 1.0 r/min. The preferred vertical position for the shelf is150 mm (6 in.) above the bottom of the oven (exclusive ofspace occupied by the heating element), and the shelf shall belocated as close to this position as permitted
18、by compliancewith the requirements of 5.2 regarding thermometer placement.The shelf shall be constructed or marked in such a way that thesample containers can be placed in the same position duringeach test. There shall be a minimum of two and a maximum ofsix sample container positions. Each sample c
19、ontainer positionshall be symmetrical with respect to the shaft and to any holesin the shelf. The number of sample container positions shall bethe maximum that will fit on the shelf without violating theabove requirements and without excessive overhang.5.2 ThermometerAn ASTM Loss on Heat Thermometer
20、having a range from 155 to 170C and conforming to therequirements for Thermometer 13C, as prescribed in Specifi-cation E 1 shall be used for determining the test temperature.The thermometer shall be supported from the shaft of thecircular shelf in a vertical position at a point equidistant fromthe c
21、enter and outer edge of the shelf. The bottom of thethermometer bulb shall be 40 mm (1.5 in.) above the top of theshelf. The thermometer shall be radially centered over a samplecontainer position5.3 ContainerA cylindrical pan, 140 mm (512 in.) ininside diameter and 9.5 mm (38 in.) deep with a flat b
22、ottom.Fifty millilitres of the sample in this size container give a filmthickness of approximately 3.2 mm (18 in.). Pans shall be madeof stainless steel and shall have a metal thickness of approxi-mately 0.64 mm (0.025 in.).NOTE 1Pans have a tendency to become warped or bent with use.Although tests
23、indicate that a small amount of warping does notsignificantly affect results, frequent inspection to eliminate warped ordamaged pans is advisable. The indicated metal thickness has been foundto provide adequate rigidity without excessive weight. Stainless steel pansmanufactured from 0.6-mm thick (No
24、. 24) stainless sheet gage steelcomply with the recommended thickness. Pans made from 0.48 mm-thick(No. 26) stainless sheet gage metal are also acceptable but have a greatertendency to warp during use.6. Preparation of Samples6.1 Place sufficient material for the test in a suitablecontainer and heat
25、 to a fluid condition. Extreme care should betaken so that there is no local overheating of the sample andthat the highest temperature reached is not more than 150C(302F). Stir the sample during the heating period, but avoidincorporating air bubbles in the sample. Weigh 506 0.5 g intoeach of two or
26、more tared containers meeting the requirementsof 5.3.6.2 At the same time, pour a portion of the sample into thecontainers specified for measurement of original asphalt prop-erties. Complete the tests by appropriate ASTM test methods.6.3 If the quantitative value of the mass change is desired,cool t
27、he samples for the oven test to room temperature andweigh each sample separately to the nearest 0.001 g. If themass change is not required, allow the samples to cool toapproximately room temperature before placing in the oven asdirected in 7.2.7. Procedure7.1 Level the oven so that the shelf rotates
28、 in a horizontalplane. The maximum tilt during rotation shall be not more than3 from the horizontal.7.2 Place an empty sample container in each of the prede-termined sample container positions on the rotating shelf.Adjust the temperature control so the specified thermometer(see 5.2) reads 163 6 1C (
29、325 6 2F) when the oven is atequilibrium. Once adjustment is complete, the empty samplecontainers may be removed at the discretion of the operator.However, the temperature control shall not be readjusted onceany sample containers are removed.NOTE 2Removing sample containers will affect convection pa
30、tternsin the oven, and may cause the thermometer reading to change from thedesired level. This is normal, and occurs because the thermometer is notin the same location as the temperature control sensor. Replacing thecontainers should cause the thermometer reading to return to the originallevel.7.3 W
31、ith the oven preheated and adjusted as described in7.2, quickly place the asphalt samples in the predeterminedsample container positions on the circular shelf (Note 3 andNote 4). Fill any vacant positions with empty sample contain-ers, so that every sample container position is occupied. Closethe ov
32、en door and start rotating the shelf. Maintain thespecified temperature range for 5 h after the sample has beenintroduced and the oven has again reached that temperature.The 5-h period shall start when the temperature reaches 162C(323F) and in no case shall the total time that a sample is inthe oven
33、 be more than 514 h. At the conclusion of the heatingperiod, remove the samples from the oven. If the mass changeis not being determined, proceed in accordance with 7.5. If themass change is being determined, cool to room temperature,weigh to the nearest 0.001 g, and calculate the mass change onthe
34、basis of the asphalt in each container (Note 5).NOTE 3Materials having different mass change characteristics shouldnot generally be tested at the same time due to the possibility ofcross-absorption.NOTE 4This test method does not prohibit placing an asphalt samplein the position under the thermomete
35、r. However, it is recommended thatthis position not be used for a sample, and that an empty pan remain in thisposition, in order to minimize the risk associated with thermometerbreakage.NOTE 5When complete tests cannot be made in the same day, and ifthe mass change is being determined, weigh the res
36、idues and store themovernight before reheating. If the mass change is not being determined,transfer the residue to the 240-mL (8-oz) container as described in 7.5before storing overnight.7.4 After weighing the samples, place them on a refactory-board and then on the shelf of the oven maintained at 1
37、63C(325F). Close the oven and rotate the shelf for 15 min, removethe samples and board(s), and immediately proceed as de-scribed in 7.5.7.5 Transfer the material from each pan into an 240-mL(8-oz) ointment tin. Remove substantially all of the materialfrom the pans by scraping with a suitable spatula
38、 or putty knife.Stir the combined residues thoroughly, placing the 240-mL(8-oz) container on a hot plate to maintain the material in aD 1754 97 (2002)2fluid condition if necessary. Complete the tests on residue byappropriate ASTM test methods within 72 h of performing thistest.NOTE 6Care should be t
39、aken if the sample is reheated more thanonce, since excessive reheating can affect the apparent severity of the test.8. Report8.1 Report the values of the original asphalt propertiesmeasured in 6.2 and the residue property values as measured in7.5. Viscosity change may also be expressed as the ratio
40、 of theresidual asphalt viscosity to the original asphalt viscosity.Penetration change is evaluated as the penetration of theresidue expressed as the percentage of the original penetration.8.2 Report ductility or other test results in accordance withthe appropriate ASTM test methods.8.3 When determi
41、ned, report the average mass change of thematerial in all containers as mass percent of the originalmaterial. A mass loss shall be reported as a negative number,while a mass gain shall be reported as a positive number.NOTE 7This test can result in either a mass loss or a mass gain.During the test, v
42、olatile components evaporate (causing a decrease inmass), while oxygen reacts with the sample (causing an increase in mass).The combined effect determines whether the sample has an overall massgain or an overall mass loss. Samples with a very low percentage ofvolatile components will usually exhibit
43、 a mass gain, while samples witha high percentage of volatile components will usually exhibit a mass loss.9. Precision and Bias9.1 Criteria for judging the acceptability of the viscosity at60C (140F) and 135C (275F), viscosity ratio at 60C(140F), change in penetration at 25C (77F), and masschange te
44、st results obtained by this method are given in Table1. The figures given in Column 2 are the standard deviationsthat have been found to be appropriate for the materials andconditions of test described in Column 1. The figures given inColumn 3 are the limits that should not be exceeded by thediffere
45、nce between the results of two properly conducted tests.The figures given in Column 4 are the coefficients of variationthat have been found to be appropriate for the materials andconditions of test described in Column 1. The figures given inColumn 5 are the limits that should not be exceeded by thed
46、ifference between the results of two properly conducted testsexpressed as a percent of their mean.9.2 Criteria for judging the acceptability of ductility data at15.6C (60F) are given in Table 1. Each test result is theaverage of three ductility measurements.10. Keywords10.1 aging; asphalt cement; Th
47、in-Film Oven Test (TFOT)TABLE 1 Precision of Test on ResidueMaterial and Type IndexStandardDeviation(1s)Acceptable Range ofTwo Results (d2s)Coefficient of Variation(percent ofmean) (1s%)Acceptable Range ofTwo Results (percentof mean) (d2s%)Single-operator precision:Percentage of retained penetration
48、 1.43 4.0 . .Change in mass percentage:Not more than 0.4 % (max) 0.014 0.04 . .Greater than 0.4 % . . 2.9 8.0Viscosity at 60C (140F) . . 3.3 9.3Viscosity at 135C (275F) . . 2.0 5.7Ratio:viscosity at 60C 140F! after testviscosity at 60C 140F! before test. . 5.6 16.0Ductility at 15.6C (60F), cmA720Mul
49、tilaboratory precision:Percentage of retained penetration 2.90 8.0 . .Change in mass percentage:Not more than 0.4 % (max) 0.055 0.16 . .Greater than 0.4 % . . 14.0 40.0Viscosity at 60C (140F) . . 11.6 33.0Viscosity at 135C (275F) . . 6.4 18.0Ratio:Bviscosity at 60C 140F! after testviscosity at 60C 140F! before test. . 9.1 26.0Ductility at 15.6C (60F), cmA12 34AThis is based on the analysis of data resulting from tests by 60 laboratories on four asphalts with average ductilities ranging from 20 to 40 cm.BMultilaborato
