1、Designation: D7229 08 (Reapproved 2013)1Standard Test Method forPreparation and Determination of Bulk Specific Gravity ofDense-Graded Cold Mix Asphalt (CMA) Specimens byMeans of Superpave Gyratory Compactor1This standard is issued under the fixed designation D7229; the number immediately following t
2、he designation indicates the year oforiginal adoption or, in the case of 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.1NOTEEditorially corrected 9.1 in D
3、ecember 2013.1. Scope1.1 This test method concerns the preparation and compac-tion of cylindrical specimens of dense-graded cold mix asphalt(CMA) using the Superpave gyratory compactor (SGC).1.2 This test method is applicable for road mixes or plantmixes prepared at ambient temperatures.1.3 This tes
4、t method also refers to the determination of thebulk specific gravity of the compacted CMA.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 A precision and bias statement for this test method hasnot been developed at this
5、 time. Therefore, this test methodshould not be used for acceptance or rejection of a material forpurchasing purposes.1.6 This standard 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-pria
6、te safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C566 Test Method for Total Evaporable Moisture Content ofAggregate by DryingD8 Terminology Relating to Materials for Roads and Pave-mentsD977 Specificatio
7、n for Emulsified AsphaltD1188 Test Method for Bulk Specific Gravity and Density ofCompacted Bituminous Mixtures Using Coated SamplesD2041 Test Method for Theoretical Maximum SpecificGravity and Density of Bituminous Paving MixturesD2397 Specification for Cationic Emulsified AsphaltD2489 Practice for
8、 Estimating Degree of Particle Coating ofBituminous-Aggregate MixturesD2726 Test Method for Bulk Specific Gravity and Densityof Non-Absorptive Compacted Bituminous MixturesD3203 Test Method for Percent Air Voids in CompactedDense and Open Bituminous Paving MixturesD3628 Practice for Selection and Us
9、e of EmulsifiedAsphaltsD4215 Specification for Cold-Mixed, Cold-Laid BituminousPaving MixturesD6752 Test Method for Bulk Specific Gravity and Densityof Compacted Bituminous Mixtures Using AutomaticVacuum Sealing MethodD6925 Test Method for Preparation and Determination ofthe Relative Density of Hot
10、Mix Asphalt (HMA) Speci-mens by Means of the Superpave Gyratory CompactorD6934 Test Method for Residue by Evaporation of Emulsi-fied AsphaltD6998 Practice for Evaluating Aggregate Coating usingEmulsified Asphalts3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology D8.3.2 Defi
11、nitions of Terms Specific to This Standard:3.2.1 dense-graded aggregate emulsified asphalt coldmixturesmixtures of dense-graded aggregate and emulsifiedasphalt uniformly mixed at or near ambient temperature.3.2.2 dense-graded cold mix asphalt (CMA)emulsifiedasphalt that has been mixed with aggregate
12、, dry, and com-pacted by a suitable compacting device.3.2.3 nominal maximum aggregate/sieve sizeone sievesize larger than the first sieve to retain more than 10 %.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcomm
13、ittee D04.27 onCold Mix Asphalts.Current edition approved Dec. 1, 2013. Published February 2014. Originallyapproved in 2006. Last previous edition approved in 2008 as D7229 08. DOI:10.1520/D7229-08R13E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Se
14、rvice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 This test method
15、 is used to prepare specimens fordetermination of the bulk specific gravity of a cured compactedspecimen. It covers modifications to Test Method D6925 forpreparation of CMA by means of the SGC.4.2 This test method is useful for monitoring the density ofthe specimen during the compaction process. It
16、is suitable forlaboratory design and field control of CMA.4.3 Local end-use specifications should be developed toestablish conformance to the job and user requirements.5. Apparatus5.1 Superpave Gyratory CompactorAn electrohydyaulicor electromechanical compactor with a ram and ram heads asdescribed i
17、n Test Method D6925.6. Materials6.1 Aggregates3Dense-graded aggregates meeting the re-quirements of Specification D4215 are among those suitablefor emulsified asphalt cold mixtures or further guidance shouldbe obtained from the Cold Mix Manual.6.2 EmulsionsTwo types of emulsified asphalt are usedfor
18、 producing dense-graded emulsified asphalt cold mixturesand their selection are described in Practice D3628. These aredesignated as slow-setting and medium-setting emulsions.Medium-setting emulsions are used with aggregates that do nothave excessive amounts passing the 0.075-mm sieve. Slow-setting e
19、mulsions are normally used with the more denseaggregates with larger amounts passing the 0.075-mm sieve.Specifications for these emulsions are given in SpecificationsD977 and D2397.7. Procedure7.1 Determination of Trial Emulsion ContentIf needed, asimple formula for base mixtures and one for surface
20、 mixturesis used. These formulas are based on the percentage ofaggregate passing the 4.75-mm sieve and, in most cases, givea satisfactory starting point.7.1.1 Determine the residue content of the emulsion to beused by Test Method D6934 or another suitable acceptableprocedure.7.1.2 Estimate the initi
21、al emulsified asphalt content basedon the dry weight of aggregate as follows:47.1.2.1 Base Mixtures:E 50.06B10.01C! 3100A(1)7.1.2.2 Surface Mixtures:E 50.07B10.03C! 3100A(2)where:A = percent residue of the emulsion by distillation or othersuitable procedure (see 7.1.1),B = percent of dry aggregate p
22、assing the 4.75-mm sieve,C = 100 B (dry aggregate retained on the 4.75-mm sieveand above), andE = percent emulsified asphalt based on dry weight ofaggregate.7.2 Coating TestPreliminary evaluation of the emulsifiedasphalt selected for mixture preparation is accomplishedthrough a coating test. The tri
23、al emulsion content as deter-mined in 7.1 is combined with the wet job aggregate correctedto dry weight. Coating is visually estimated by the user assatisfactory or unsatisfactory for the intended use of the mix(surface mixtures require a greater degree of coating than dobase mixtures). Local end-us
24、e specifications or agreementbetween user and supplier should be developed to determinethe degree of coating. If the degree of coating is consideredsatisfactory, proceed to making the mix. If the coating isconsidered unsatisfactory, select another grade of emulsion asdescribed in Practice D3628 and
25、start over from 7.1.NOTE 1As a general guideline, aggregates not exceeding 20 %passing the 0.075-mm sieve can be used for the slow-setting emulsions,and aggregates with less than 10 % passing the 0.075-mm sieve are usedfor the medium-setting emulsions. Local end-use specifications should bedeveloped
26、 to finalize these requirements since aggregates vary fromregion to region.NOTE 2Coating may be quantitatively calculated by using theprocedure described in Practice D2489.NOTE 3The emulsified asphalt/job aggregate coating test in TestMethod D6998 can be used for this screening process.7.3 Preparati
27、on of Test SpecimensPrepare a specimenusing the emulsion content determined in 7.1. If the mixture inthe coating tests (7.2) appears to be dry, start with the trialemulsion content (7.1). Conversely, if the mixture appears rich,reduce the emulsion content.NOTE 4A trial emulsion content of 8 % emulsi
28、on is a good startingpoint. Other trial blends can be 1 % higher or 1 % lower. Other trial blendswould then be 9, 8, and 7 % of emulsion content, respectively. A normaldifference between the emulsion content levels is 1 %, which is a residualdifference of 0.65 % for an emulsion with a 65 % residue c
29、ontent.7.4 Preparation of Aggregates:7.4.1 Determine the moisture content of the aggregatefollowing Test Method C566.7.4.2 Weigh the appropriate amount of wet job aggregate,corrected to dry aggregate weight to obtain a compactedspecimen height of 115 6 5 mm, into suitable mixing bowls foreach indivi
30、dual batch. Care must be taken so that the aggregatefor each batch is representative of the project aggregate. Ifnecessary, the aggregate maybe dried and separated into sizesthen reblended into individual batch sizes. If this is done, waterequivalent to stockpile moisture must be added to each batch
31、and the mixture covered to prevent loss of moisture for about24 h before mixing with emulsion.NOTE 5It may be necessary to produce a trial specimen to achieve thisheight requirement. Generally, 4500 to 4700 g of aggregate are required.7.4.3 If premixing water is required, pour the predeterminedamoun
32、t (from section 7.2) onto the aggregate and hand mix for60 s or until uniform. As an option, mechanical mixing may be3Asphalt Cold Mix Manual, Asphalt Institute, Manual Series No. 14 (MS-14),3rd Edition, 1997.4A Basic Asphalt Emulsion Manual, Asphalt Institute, Asphalt EmulsionManufactures Associati
33、on, Manual Series No. 19 (MS- 9), 3rd Edition.D7229 08 (2013)12used. This must be done just before the addition and mixingwith the emulsified asphalt.7.4.4 Weigh a predetermined amount of emulsion (fromsection 7.2) and add to the wet aggregate. Mix thoroughly for60 s until the aggregates are coated.
34、 As an option, mechanicalmixing may be used. Excessive mixing will cause the mix tostrip.7.4.5 Place the emulsion mix in a pan and dry in aforced-draft oven for 3.0 6 0.1hat306 0.1C.7.5 Compaction:7.5.1 Prepare the sample for compaction as described in thisprocedure and follow the densification proc
35、edure of Section 8of Test Method D6925.7.5.2 Place the base plate and a paper disk in the bottom ofthe mold.7.5.3 Place the mixture into the mold in one lift. Care shouldbe taken to avoid segregation in the mold. After all the mix isin the mold, level the mix, and place another paper disk andupper p
36、late (if required) on top of the leveled material.7.5.4 Load the charged mold into the compactor and centerthe loading ram.7.5.5 Apply a constant vertical pressure of 600 6 60 kPa forthe first five gyrations and 600 6 18 kPa during the remainderof the compaction process as described in Test Method D
37、6925.7.5.6 Allow the compaction to proceed to the desirednumber of gyrations based on end-use requirement.NOTE 6Note that this process of loading, densification, and unloadingof the CMA is similar to the HMA process described in sections 6.1through 6.11 of Test Method D6925, except temperatures, han
38、dling times,and aging requirements are different.NOTE 7Present practice is to use 33 6 3 gyrations. Previous roundrobin between five laboratories indicated that above 40 gyrations nofurther height reduction of the compacted mix was observed.7.5.7 Extrude the sample from the mold and weigh. Placethe
39、compacted specimen in the forced air-draft oven set at 306 1C and cure for 20 6 0.1 h.NOTE 8The curing protocol in this standard represents only a practicebeing followed by some practitioners and was used in a round-robinencompassing five laboratories. It is not intended to cover or simulate thelarg
40、e spectrum of varying field practices and pavement performanceconditions. In the application of this standard the user may define adifferent curing protocol that better represents the local field practice; onethat better simulates the expected short and long term conditions affectingthe mixture prop
41、erties.7.6 Densification:7.6.1 Determine the bulk specific gravity of the extrudedspecimen as described in Test Methods D1188, D2726 orD6752.7.6.2 Determine the bulk density by dividing the weight ofthe specimen in air by its calculated volume, determined basedon geometric measurements (height and m
42、old diameter).Db5WaHA; A 5 3 D2/4 (3)where:Db= measured bulk density of a compacted mixturespecimen,D = diameter of specimen,Wa= specimen weight in air,H = height of compacted specimen, andA = area of cylindrical specimen.7.6.3 Other volumetric properties such as voids, voids filled,and voids in the
43、 mineral aggregate are determined followingthe appropriate Test Methods D2041 and D3203 and thecalculations described in Asphalt Institute Manual MS-2.58. Report8.1 Report the following information:8.1.1 Date and time of specimen preparation;8.1.2 Specimen identification including grade of emulsion;
44、8.1.3 Percentage of emulsified asphalt in specimen to thenearest 0.1 %;8.1.4 Mass of the specimen to the nearest 0.1 g;8.1.5 Bulk specific gravity of the compacted specimen(Gmb) by Test Methods D1188, D2726,orD6752 to the nearest0.001; and8.1.6 Height of the compacted specimen after each gyration(hx
45、) to the nearest 0.1 mm if required.9. Precision and Bias9.1 The between-laboratory reproducibility of this testmethod is underway and will be available on or beforeDecember 1, 2017. A preliminary study between fivelaboratories, using one emulsion and one set of aggregates andthree emulsion content
46、of a single mix and two replicates,indicated that a single-operator precision greater than 1 % ofthe mean should be considered suspect and for between-laboratory precision greater than 3 % of the mean should beconsidered suspect. This test method should not be used foracceptance or rejection of a ma
47、terial for purchasing purposes.9.2 BiasNo information can be presented on the bias ofthe procedure because no material having an accepted refer-ence value is available.10. Keywords10.1 aggregates; cold mix asphalt; compaction; emulsifiedasphalt; emulsions; gyratory; medium-setting emulsions; slow-se
48、tting emulsions5Mix Design Methods for Asphalt Concrete and other Hot-mix types, AsphaltInstitute, Manual Series No. 2 (MS-2) 6th Edition, 1995.D7229 08 (2013)13ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this sta
49、ndard. 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 committee 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 caref
