1、Designation: D 6608 00 (Reapproved 2006)Standard Practice forthe Identification of Trinidad Lake Asphalt in Asphalt Mixes1This standard is issued under the fixed designation D 6608; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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 practice shall be used for the qualitative determi-nation of Trinidad Lake Asphalt in Trinidad Lake M
3、odifiedAsphalt Cements obtained from production blends or recov-ered binder from asphalt paving mixtures.1.2 It is limited to the binder content of Trinidad LakeModified Asphalt (Specification D 5710) used in the construc-tion of asphalt pavements.1.3 This standard does not purport to address all of
4、 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:2D 140 Practice for Sampl
5、ing Bituminous MaterialsD 1856 Test Method for Recovery of Asphalt From Solu-tion by Abson MethodD 2172 Test Methods for Quantitative Extraction of Bitu-men From Bituminous Paving MixturesD 5710 Specification for Trinidad Lake Modified AsphaltE 1 Specification for ASTM Liquid-in-Glass Thermometers3.
6、 Summary of Test Method3.1 A polished copper strip is immersed in a given quantityof sample and heated at a temperature and for a given timecharacteristic of the material being tested. At the end of thisperiod the copper strip is removed, washed, and compared withthe classifications of the TLA Coppe
7、r Tarnishing Ranges forcopper strips.4. Significance and Use4.1 Bitumen contains sulfur compounds most of which areremoved during refining, the resulting asphalt cement alsocontains sulfur compounds which are released at the tempera-tures above 230C (446F). Trinidad Lake Modified Asphaltcontains sul
8、fur compounds, which are released at lower tem-peratures between 170C (338F) and 230C (446F). Therelease of sulfur from Trinidad Lake Modified Asphalt tar-nishes the copper strip and appears to be related directly to thetotal TLA content. The copper strip test is designed to assessthe qualitative pr
9、esence of TLA in asphalt cements.5. Apparatus5.1 Test Tubes, 25 by 150 mm.5.2 Provide a bath, which can maintain a constant tempera-ture of 210 6 1C (410 6 2F) and 225 6 1C (437 6 2F).The bath should have suitable supports to hold the test tubes ina vertical position and immersed to a depth of about
10、 100-mm(4-in.). Oil or aluminum block baths are suitable.5.3 Thermometer, partial immersion for indicating the re-quired test temperature, with graduations 1C (2F) or less. TheASTM 2C (2F) thermometer is suitable.5.4 Polishing Vise, to hold the copper strip firmly withoutmarring the edge while polis
11、hing. Any suitable holder may beused provided that the surface is held tightly and the surfacebeing polished is supported above the surface of the holder.5.5 Viewing Test Tubes, flat glass test tubes, are convenientfor protecting corroded strip and may be used for closeinspection and storage.6. Mate
12、rials6.1 Wash SolventAny volatile, sulfur free hydrocarbonsolvent may be used that would show no tarnish when tested at210C or 225C.NOTE 1Toluene is a suitable solvent.6.2 Polishing Materials:6.2.1 Silicone carbide grip paper of varying degrees offineness including 65 m (240 grit) paper or cloth.6.2
13、.2 Silicone carbide grains 105 m (150mesh).6.2.3 Absorbent cotton (cotton wool), pharmaceuticalgrade.6.3 Copper Strips:6.3.1 SpecificationsUse strips 12.5 mm (12 in.) wide, 1.5to 3.0 mm (116 to18 in.) thick, cut 75 mm (3 in.) long fromsmooth-surface, hard temper, cold-finished copper of 99.9+ %purit
14、y; electrical bus bar stock is generally suitable (see Annex1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.47 onMiscellaneous Asphalt Tests.Current edition approved June 1, 2006. Published June 2006. Ori
15、ginallyapproved in 2000. Last previous edition approved in 2000 as D 6608 00.2For 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 ont
16、he ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.A1). The strips may be used repeatedly but should be discardedwhen the surfaces become deformed on handling.6.3.2 Surface PreparationRemove all surface blemishesfrom all
17、 six sides of the strip with silicone carbide paper ofsuch varying degrees of fineness as are needed to accomplishthe desired results efficiently. Finish with 65m (240 grit)silicone carbide paper or cloth, removing all marks that mayhave been made by other grades of paper used previously.Immerse the
18、 strip in wash solvent from which it can bewithdrawn immediately for final preparation (polishing) or inwhich it can be stored for future use.6.3.2.1 As a practical manual procedure for the surfacepreparation, place a sheet of paper on a flat surface, moisten itwith kerosene or wash solvent, and rub
19、 the strip against thepaper with a rotary motion, protecting the strip from contactwith the fingers using an ashless filter paper. Alternatively, thesurface of the strip can be prepared by use of motor-drivenmachines using appropriate grades of dry paper or cloth.6.3.3 Final PreparationRemove a stri
20、p from the washsolvent. Holding it in the fingers protected with ashless filterpaper, polish first the ends and then the sides with the 105m(150mesh) silicone carbide grains picked up from a cleanglass plate with a pad of cotton (cotton wool) moistened witha drop of wash solvent. Wipe vigorously wit
21、h fresh pads ofcotton (cotton wool) and subsequently handle only withstainless steel forceps. Do not touch with fingers. Clamp in avise and polish the main surfaces with silicone carbide grainson absorbent cotton. Do not polish in a circular motion. Rub inthe direction of the long axis of the strip,
22、 carrying the strokebeyond the end of the strip before reversing direction. Clean allmetal dust from the strip by rubbing vigorously with clean padsof absorbent cotton until a fresh pad remains unsoiled. Whenthe strip is clean, immediately immerse it in the preparedsample.6.3.3.1 It is important to
23、polish the whole surface of the stripuniformly to obtain a uniformly stained strip. If the edges showwear (surface elliptical) they will likely show more corrosionthan the center. The use of a vise will facilitate uniformpolishing.6.3.3.2 It is important to follow the order of preparationwith the co
24、rrectly sized silicone carbide material as describedin 6.3.2 and 6.3.3. The final preparation is with 105msilicone carbide grains. This is a larger grain size than the65m paper used in the surface preparation stage. The reasonfor this use of larger silicone carbide grains in the finalpreparation is
25、to produce asperities (controlled roughness) onthe surface of the copper which acts as sites for the initiation ofcorrosion reactions.7. Sample Preparation7.1 The binder shall be acquired either from productiontanks, according to Practice D 140, or from asphalt mixes,according to the procedures in T
26、est Method D 2172 and TestMethod D 1856. Store the sample material in a clean, darkglass or metal container or other suitable containers such thatthe properties of the sample are not affected. Fill the containersas completely as possible and seal immediately.7.2 To produce a test sample, heat the re
27、covered binderslowly to approximately 135C with constant stirring, by hand,until molten. Stir the sample thoroughly again before decantinginto the sample test tubes.8. Procedure8.1 Place 1520 mL of the molten recovered binder sample,which is free of any entrained water or suspended water, intoeach o
28、f two clean and dry test tubes. Insert a polished copperstrip into each test tube within one (1) minute of completing thefinal strip preparation. Ensure that the strip is vertically held inthe sample with approximately 4457 mm (134 214 in.) of thestrip projecting out of the sample mixture.8.2 Place
29、the test tubes in the bath, which has beenmaintained at 210C and leave for 25 min.8.3 Strip Examination:8.3.1 Empty the contents of each test tube into a 150mLtall-form beaker, allowing the strip to slide out gently to avoidbreakage. Remove the strip immediately with clean stainlesssteel forceps and
30、 immerse in the wash solvent for not longerthan 30 s. Remove and blot dry with quantitative filter paper.Inspect the strip for evidence of tarnishing or color changewhile holding at an angle of approximately 45. Compare thestrip to the classification given in the TLA Copper TarnishingRanges (see Tab
31、le 1).8.3.2 In handling the test strip during inspection, care mustbe taken to avoid damage by marking or staining. A flat glasstube, which can be stoppered with absorbent cotton, may beused as a viewing aid.8.4 If the surface of the strip is unchanged, raise the bathtemperature to 225C and allow to
32、 stand for 25 min. Replacethe strip in the test tube and place in the bath for 25 min.Repeat paragraph 8.3 for strip examination.9. Interpretation9.1 Interpret the Trinidad Lake Asphalt presence and con-tent of the sample accordingly as the appearance of the teststrip agrees with one of the strips i
33、n the TLA CopperTarnishing Standard in Table 1.9.2 If there is a color change at 210C, conclude that thebitumen contains TLA and has a TLA content greater than25 %.9.3 If there is a color change at 225C, conclude that thebinder contains TLA and has a TLA content of less than 25 %.10. Report10.1 Repo
34、rt the results as the presence of greater than 25 %of TLA, the presence of less than 25 % of TLA or the absenceof TLA in the asphalt mix.TABLE 1 TLA Copper Tarnishing RangesClassificationTemperature,CDesignation Description TLA Presence1 210 None Clean Strip 0 25 % TLAA2 210Moderate toheavytarnishDa
35、rk blue,black-green 25 % TLA3 225Slight tomoderatetarnishRed-blue,green 25 % TLA4 225 None Clean strip 0 % TLAAFurther testing at 225C is required for determination of the absence orpresence of TLA.D 6608 00 (2006)211. Keywords11.1 asphalt mix; copper strip finish; copper tarnishing;sulfur compound;
36、 Trinidad Lake AsphaltANNEXA1. COPPER QUALITYA1.1 Copper QualityA1.1.1 Hard-tempered, cold-finished type (ETP) electro-lytic tough pitch copper.3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
37、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 committee and must be reviewed every five
38、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 meeting of theresponsible technical com
39、mittee, 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, PO Box C700, West Conshohocken, PA 1
40、9428-2959,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).3Conforming to Copper Development Assn. (CDA), United States of AmericaNo. 110, or to British Standard (BS) 1036:1952, which have proper quality.D 6608 00 (2006)3
