1、Designation: D3744/D3744M 18Standard Test Method forAggregate Durability Index1This standard is issued under the fixed designation D3744/D3744M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in
2、 parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of a durabilityindex of an aggregate. The calculated durability index is avalue indicating the relativ
3、e resistance of an aggregate toproduction of detrimental clay-like fines when subjected to theprescribed mechanical methods of degradation.1.2 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equ
4、ivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with the standard.1.2.1 Measurements of volume and mass are only given inSI units because they are the only units typically used inpractice when performing thi
5、s test method.1.2.2 Measurements in Section 11, Section 15, Eq 3, Eq 4,and Table 1 are only given in inch-pound units because theequipment used in these sections is only manufactured usingthe inch-pound system.1.3 This standard does not purport to address all of thesafety concerns, if any, associate
6、d with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recogni
7、zed principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C127 Test Method for Re
8、lative Density (Specific Gravity)and Absorption of Coarse AggregateC136/C136M Test Method for Sieve Analysis of Fine andCoarse AggregatesC702/C702M Practice for Reducing Samples of Aggregateto Testing SizeD75/D75M Practice for Sampling AggregatesD2419 Test Method for Sand Equivalent Value of Soils a
9、ndFine AggregateD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingE11 Specification for Woven Wire Test
10、 Sieve Cloth and TestSieves3. Summary of Test Method3.1 This test method was developed to permit prequalifica-tion of aggregates proposed for use in the construction oftransportation facilities. This test establishes an aggregatesresistance to generating fines when agitated in the presence ofwater.
11、Separate and different test procedures are used toevaluate the coarse and the fine portions of an aggregate.3.2 A sample of coarse aggregate is prepared to a specificgrading and then washed in a washing vessel secured in amechanical agitator for 2 min. After discarding the minus4.75-mm (No. 4) mater
12、ial, dry the washed test sample.3.3 The coarse aggregate test sample is then mechanicallyagitated in the washing vessel for a period of 10 min. Arepresentative portion of the resulting wash water and minus75-m (No. 200) size fines is collected and mixed with a stockcalcium chloride solution and plac
13、ed in a plastic cylinder.Aftera 20-min sedimentation time, the level of the sediment columnis read. The height of the sediment value is then used tocalculate the durability index of the coarse aggregate (Dc).3.4 The fine aggregate sample is prepared by washing aspecific quantity of the material in t
14、he washing vessel securedin a mechanical agitator for 2 min. All minus 75-m (No. 200)size material is washed from the sample through a 75-m (No.200) sieve and discarded. The plus 75-m (No. 200) fraction isdried.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Mater
15、ials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved Sept. 1, 2018. Published September 2018. Originallyapproved in 1979. Last previous edition approved in 2011 as D3744/D3744M 11a.DOI: 10.1520/D3744_D3744M-18.2For referenced ASTM standards, visit t
16、he 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 onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
17、United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barr
18、iers to Trade (TBT) Committee.13.5 The fine aggregate test sample is tested by the standardsand equivalent test method (Test Method D2419) except formodifications to the test sample preparation and duration of theshaking time. The mechanical shaker method is required. Ashaking time of 10 min instead
19、 of 45 s is used.3.6 This test method includes procedures for testing aggre-gates exhibiting a wide range in specific gravity, includinglightweight and porous coarse aggregates, and also proceduresfor testing small maximum-size aggregate which is too fine totest as a coarse aggregate and too coarse
20、to consider as a fineaggregate, such as a pea gravel or a very coarse sand.3.7 The durability index for coarse aggregate (Dc) or for fineaggregate (Df) is calculated, as applicable, by appropriateequations presented in the method. The durability index of awell-graded aggregate containing both coarse
21、 and fine fractionsis defined as the lowest of the two values, Dcor Df, obtained bythe test. This value is recommended to be the controlling valuefor specification purposes.4. Significance and Use4.1 This test method assigns an empirical value to therelative amount, fineness, and character of clay-l
22、ike materialthat may be generated in an aggregate when subjected tomechanical degradation.4.2 The procedure has been used in limited geographicalareas of the United States, and the results have been correlatedwith aggregate performance in various constructionapplications, including: aggregate base,
23、permeable material forbackfill, fine concrete aggregate, and riprap for rock slopeprotection.3,44.3 Aminimum durability index is permitted to be specifiedto prohibit the use of an aggregate in various constructionapplications that is prone to degradation, resulting in genera-tion of clay-like fines.
24、4.4 This test method provides a rapid test for evaluation ofthe quality of a new aggregate source. Research has indicatedit may also be suitable for use instead of the sodium sulfatesoundness test for evaluating the durability characteristics offine aggregate for use in portland cement concrete, the
25、rebyreducing the need for time-consuming and expensive sound-ness tests.34.5 Although the application of this method has beenlimited to aggregates for specific construction uses, the possi-bility exists for expanding the application of this method tocontrol the quality of aggregates used in other ar
26、eas ofconstruction, such as aggregates for use in bituminous pavingmixtures, coarse aggregate for use in portland cement concrete,and aggregate for use as railroad ballast.NOTE 1The text of this test method references notes and footnoteswhich provide explanatory material. These notes and footnotes (
27、excludingthose in tables and figures) shall not be considered as requirements of thetest method.NOTE 2The quality of the results produced by this standard aredependent on the competence of the personnel performing the procedureand the capability, calibration, and maintenance of the equipment used.Ag
28、encies that meet the criteria of Specification D3666 are generallyconsidered capable of competent and objective testing, sampling,inspection, etc. Users of this standard are cautioned that compliance withSpecification D3666 alone does not completely ensure reliable results.Reliable results depend on
29、 many factors; following the suggestions ofSpecification D3666 or some similar acceptable guideline provides ameans of evaluating and controlling some of those factors.5. Apparatus5.1 Washing Vessel or Wash Vessel (Pot)A flat-bottomed,straight-sided cylindrical vessel similar to the design shown inF
30、ig. 1, with a volume of approximately 7 L and inner diameterof approximately 200 mm 8 in. The vessel lid must beequipped with a rubber gasket or another means of preventingleaks during agitation.5.2 Collection PanAround pan (at least 230 mm 9 in. indiameter and approximately 100 mm 4 in. deep), suit
31、able tocollect the wash water from the washed sample. The pan shallhave vertical or nearly vertical sides and shall be equipped asnecessary to hold the wire mesh of a 200-mm 8-in. diametersieve at least 75 mm 3 in. above the bottom. An adaptor thatwill not allow loss of fines or wash water may be us
32、ed to nestthe sieve with the container, or the sieve may be nested with ablank sieve frame resting in the bottom of the pan.5.3 Mechanical AgitatorA mechanical device designed tohold the wash vessel in an upright position while subjecting itto a lateral reciprocating motion of 45 6 6mm134 614 in.at
33、a rate of 285 6 10 complete cycles per minute. See Note 3.NOTE 3The Tyler portable shaker previously referenced and requiringmodifications hasnt been manufactured since 1986. Further, it was amanufactured sieve shaker that required each customer to modify theequipment from its original design to mee
34、t the lateral reciprocatingrequirements listed in 5.3. While it is possible some modified Tylershakers are still in use today, there are other manufactured agitators that donot require customer modifications to meet the lateral reciprocatingrequirements listed in 5.3.5.4 All equipment required to pe
35、rform the sand equivalentvalue of soils and fine aggregate (Test Method D2419).5.5 SievesThe sieves shall conform to Specification E11.5.6 BalanceA balance having a minimum capacity of500 g and meeting the requirements of Guide D4753, ClassGP5.5.7 OvenAn oven capable of maintaining a temperature of1
36、10 6 5 C 230 6 10 F.5.8 Graduated CylinderA 1000-mL graduated cylinder.5.9 FunnelA funnel of sufficient size to allow for transferof wash water from the collection pan to the graduatedcylinder.6. Reagents and Materials6.1 Calcium Chloride SolutionsUse stock and workingcalcium chloride solutions as s
37、pecified in the Reagents andMaterials section of Test Method D2419.3Hamilton, R. D., Smith, R. E., and Sherman, G. B., “Factors Influencing theDurability ofAggregates,” Research Report 633476, State of California, Division ofHighways, Materials and Research Department, June 1971.4Hveem, F. N., and S
38、mith, T. N., “Durability of Aggregates,” Research Report,State of California, Division of Highways, Materials and Research Department,January 1964.D3744/D3744M 1826.2 WaterUse distilled or demineralized water for thenormal performance of this test method. The test results arelikely to be affected by
39、 certain minerals dissolved in water.However, if it is determined that local tap water is of suchpurity that it does not affect the test results, the use of tap wateris permissible in place of distilled or demineralized water. Forreferee purposes, distilled or demineralized water shall be usedfor al
40、l steps in the test.7. Temperature Control7.1 This test method is normally performed without stricttemperature control; however, for referee purposes, retest thematerial with the temperature of the distilled or demineralizedwater and the working calcium chloride solution at 22 6 3C72 6 5 F.8. Sampli
41、ng8.1 Obtain samples of the aggregate to be tested in accor-dance with Practice D75/D75M.9. Initial Sample Preparation9.1 Dry aggregate samples sufficiently to permit a completeseparation on the 4.75-mm (No. 4) sieve and to develop afree-flowing condition in the portion passing the sieve. Performdry
42、ing by any method that does not heat the aggregate inexcess of 60 C 140 F or cause degradation of the particles.Sunlight, ovens, or forced drafts of warm air are the mostcommonly used sources of heat.9.2 If the sample contains an appreciable amount of clay,turn the aggregate frequently during the dr
43、ying process toobtain even drying throughout and to prevent the formation ofhard clay lumps.9.3 Break up any hard clods and remove coatings of finesfrom the coarse aggregate particles by any means that will notappreciably reduce the natural individual particle sizes.9.4 Determine the sample grading
44、by sieving in accordancewith Test Method C136/C136M on 19.0, 12.5, 9.5, 4.75, 2.36,FIG. 1 Washing Vessel (Wash Vessel)D3744/D3744M 183and 1.18-mm (34,12, and38-in. and Nos. 4, 8, and 16) sieves.Discard any material that is retained on the 19.0-mm (34-in.)sieve.9.5 Determine the test procedures to be
45、 used for establishingthe durability index of the aggregate based upon the grading ofthe aggregate as determined in 9.4.9.5.1 If less than 10 % of the aggregate passes the 4.75-mm(No. 4) sieve, test coarse aggregate (Procedure A) only.9.5.2 If less than 10 % of the aggregate is coarser than the4.75-
46、mm (No. 4) sieve, test fine aggregate (Procedure B) only.9.5.3 When both coarse and fine aggregate fractions areeach present in quantities equal to or greater than 10 % and ifthe percent passing the 1.18-mm (No. 16) sieve is greater than10 %, use both Procedures A and B on the appropriateaggregate s
47、izes. If the percent passing the 1.18-mm (No. 16)sieve is less than or equal to 10 %, use Procedure A orProcedure C.9.5.4 If most of the aggregate (75 to 80 %) is retainedbetween the 9.5 and 1.18-mm (38-in. and No. 16) sieves, useProcedure C only.PROCEDURE A COARSE AGGREGATE10. Test Sample Preparati
48、on10.1 Prepare a 2550 6 25-g (air-dry) preliminary testsample using the grading given below:Aggregate Size Air-Dry Mass, g19.0to12.5mm(34 to12 in.) 1070 1012.5 to 9.5 mm (12 to38 in.) 570 109.5to4.75mm(38 in. to No. 4) 910 52550 25For materials with less than 10 % in any of the size fractionsgiven i
49、n 10.1, prepare the test sample using the actualpercentage for the deficient fraction and proportionally in-crease the mass of the remaining fractions to obtain the 2550-gtest sample. Two examples follow.Example 1Less than 10 % in 19.0 to 12.5 mm (34 to12 in.) fractionAggregate Size Percent Calculation Air-Dry Mass, g19.0to12.5mm(34 to12 in.) 6 0.06 2550 153 1012.5 to 9.5 mm (12 to38 in) 26 570 (2550 153) 923 10570 + 9109.5to4.75mm(38 to No. 4) 68 910 (2550 153) 1474 5570 + 910Totals 100 2550
