1、Designation: D 3791 04Standard Practice forEvaluating the Effects of Heat on Asphalts1This standard is issued under the fixed designation D 3791; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a procedure for evaluating some ofthe effects on asphalts of heating in the presence of little or noair.1.2 This standard
3、 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
4、Standards:2D 5 Test Method for Penetration of Bituminous MaterialsD 36 Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)D 140 Practice for Sampling Bituminous MaterialsD 1079 Terminology Relating to Roofing, Waterproofing,and Bituminous MaterialsD 2170 Test Method for Kinematic Vi
5、scosity of Asphalts(Bitumens)D 2171 Test Method for Viscosity of Asphalts by VacuumCapillary ViscometerD 4402 Test Method for Viscosity Determinations of As-phalts at Elevated Temperatures Using a Rotational Vis-cometerE 1 Specification for ASTM ThermometersE 145 Specification for Gravity-Convection
6、 and Forced-Ventilation Ovens3. Terminology3.1 DefinitionsDefinitions of terms used in this practicecan be found in Terminology D 1079.4. Summary of Practice4.1 A sample of asphalt in a loosely covered container isheated to a temperature chosen by the investigator for a periodof5h6 10 min. Certain c
7、haracteristics of the asphalt after heatexposure at the test temperature chosen are then compared withthose characteristics before exposure.NOTE 1A set temperature is required when this practice is used as partof a specification. Historically, a temperature of 204C (400F) has beenused.5. Significanc
8、e and Use5.1 When asphalts are maintained at elevated temperaturesin the presence of air, their characteristics may change. Certainblown asphalts also soften when maintained near, and particu-larly above, their final blowing temperatures under virtuallyair-free conditions. This may happen if the asp
9、halt is over-heated for application purposes. This practice provides auniform heat-treatment procedure and methods for evaluatingthe effect of this treatment on some of the characteristics ofasphalts. Changes observed when asphalts are overheated arenot indicative of changes to be expected when asph
10、alts areheated to normal application temperatures.6. Apparatus6.1 OvenA forced-ventilation oven conforming to therequirements for Type IIA as prescribed in Specification E 145,capable of maintaining temperatures up to 300C (572F), andwith a chamber at least 300 by 300 by 300 mm (12 by 12 by12 in.).6
11、.2 ThermometerASTM Low-Distillation Thermometer,having a range from 1 to + 300C (30 to 580F) andconforming to the requirements for Thermometers 7C or 7F asprescribed in Specification E 1.6.3 Containers, triple-seal, friction-top, 1-L (1-qt) and 0.5-L(1-pt) cans with lids, free of any interior resino
12、us or lacquercoatings.36.4 Laboratory Timer.6.5 Hot Plate.1This practice is under the jurisdiction of ASTM Committee D08 on Roofing andWaterproofing and is the direct responsibility of Subcommittee D08.03 on Surfacingand Bituminous Materials for Membrane Waterproofing and Built-Up Roofing.Current ed
13、ition approved Jan. 1, 2004. Published January 2004. Originallyapproved in 1979. Last previous edition approved in 1996 as D 3791 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
14、mation, refer to the standards Document Summary page onthe ASTM website.3“Triple-Tite” cans, available from Continental Can Co., 633 3rd Ave., NewYork, NY, or equivalent, have been found suitable.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
15、ted States.7. Sampling7.1 Sample the asphalt in accordance with Practice D 140.8. Test Specimen and Sample8.1 Heat a minimum of 1 L (1 qt) of the asphalt on the hotplate. Stir occasionally to prevent local overheating. Keepcovered whenever possible to minimize volatiles loss. Heat thematerial until
16、sufficiently fluid to pour, but in no case more than93C (200F) above the softening point of the asphalt.8.2 When molten, pour the asphalt into a 0.5-L (1-pt)container to within 25 6 2 mm (1.0 6 0.1 in.) of the top, andalso pour test specimens for determination of the characteris-tics of the original
17、 material in accordance with the methodslisted in Section 10. Test these specimens within the time limitsspecified by the respective test procedures.NOTE 2Pour a small amount of the asphalt in the groove around thetop of the can, sufficient to act as a seal when the lid is placed loosely inposition.
18、8.3 Cover the container loosely with a lid and set aside tocool. Subject the sample to heat treatment within 18 to 24 hafter pouring.9. Procedure9.1 Preheat the test oven to the selected temperature. Placethe container on a shelf in the oven so as to permit aircirculation around it.9.2 Start the lab
19、oratory timer when the container has beenplaced in the oven and the door closed. Continue the heatingfor5h.9.3 Remove the container from the oven after 5 h. Removethe lid; if a skin is present, remove it carefully before allowingthe asphalt to cool. Stir the molten asphalt gently.9.4 Cool the sample
20、 to approximately the original pouringtemperature. Gently stir the sample to avoid air entrapment.Then, proceed to pour the test specimens.10. Test Methods10.1 Characteristics of asphalt before and after heat expo-sure may be evaluated in duplicate by any desired procedures,but the following methods
21、 are recommended:10.1.1 Softening PointTest Method D 36.10.1.2 PenetrationTest Method D 5.10.1.3 ViscosityTest Method D 2170 or D 2171 orD 4402.11. Report11.1 Report the heat-exposure temperature used.11.2 Report the presence or absence of a skin on theheat-exposed sample.11.3 Report the tests used
22、to evaluate the sample before andafter heat exposure and the individual test result from eachprocedure.12. Keywords12.1 asphalts; heat exposure; overheated; physical propertychangesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item
23、mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical commit
24、tee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a mee
25、ting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive,
26、PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D3791042
