ASTM D7172-2014 red 9377 Standard Test Method for Determining the Relative Density &40 Specific Gravity&41 and Absorption of Fine Aggregates Using Infrared《用于测定红外细骨料相对密度 (比重) 和吸收性的.pdf

1、Designation: D7172 061D7172 14Standard Test Method forDetermining Thethe Relative Density (Specific Gravity)Andand Absorption Ofof Fine Aggregates Using Infrared1This standard is issued under the fixed designation D7172; the number immediately following the designation indicates the year oforiginal

2、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.1 NOTE“2 in.” was editorially corrected to “27 in.” in Section 9.3.9 in March 20

3、09.1. Scope1.1 This test method covers the determination of the relative density (specific gravity) and absorption of fine aggregates.1.2 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.3 This standard does not purport t

4、o address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C29/C29M T

5、est Method for Bulk Density (“Unit Weight”) and Voids in AggregateC125 Terminology Relating to Concrete and Concrete AggregatesC128 Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine AggregateC566 Test Method for Total Evaporable Moisture Content of Aggregate by Dry

6、ingC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsC702 Practice for Reducing Samples of Aggregate to Testing SizeC1252 Test Methods for Uncompacted Void Content of Fine Aggregate (as Influenced by Particle Shape, Surface Texture, andGrading)D8 Te

7、rminology Relating to Materials for Roads and PavementsD75 Practice for Sampling AggregatesD4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and ConstructionMaterials Testing2.2 AASHTO Standards:3T-84 Test Method for Specific Gravity and Absorp

8、tion of Fine Aggregate2.3 Other Documents:4Operational Instructions3. Terminology3.1 DefinitionsAs defined in C125 and D8:3.1.1 Automatic Volumetric Mixer (AVM), nan automated unit to hold and agitate a volumetric flask while applying a vacuumto the flask.1 This test method is under the jurisdiction

9、 ofASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.51 on AggregateTests.Current edition approved Feb. 15, 2006June 1, 2014. Published March 2006September 2014. Originally approved in 2006. Last previous edition approved in 2006 asD7172 061. DOI: 1

10、0.1520/D7172-06E01.10.1520/D7172-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American

11、 Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.4 Available from Barnstead International,ThermoFisher Scientific, 2555 Kerper Boulevard, P.O. Box 797, Dubuque, Iowa 52004-0797, U.S.A.U.S.A., or online athttp:/cp- make certa

12、in that the aggregate in the flask is coveredwith water. Start the five-minute timer from 9.3.3.Asmall amount of water can be added at this time to rinse the sides of the flaskif necessary. Make certain not to overfill the flask, keeping the water level well below the calibration line. (See Note 5).

13、)NOTE 5A funnel may be used to help transfer the sample into the flask.9.3.5 Add a few drops of isopropyl alcohol or use a paper towel to remove bubbles if necessary to reduce error in reading themeniscus. (See Note 6).)NOTE 6An accurate meniscus determination is very important.9.3.6 After the 5 min

14、utesmin on the timer has elapsed, fill the flask with 23 6 2.00C (73 6 3F) 2C water to the calibrationmark.9.3.7 Weigh and record the mass of the flask with its contents.9.3.8 Place the flask containing the sample in the mounting bracket on top of mixer ofAVM unit. Tighten the clamp around thetop po

15、rtion of flask and then insert the rubber stopper, with vacuum hose attached, into flask.9.3.9 Turn the power switch for the AVM unit to the “on” position. Press the “start” button to begin the test. Mixer will beginto agitate material in flask. The mixer will operate for three minutes,3 min, then t

16、he vacuum pump will engage at a level of 56cm (22 in.) Hg for another three minutes3 min to remove air from the sample. The last five minutes5 min of the test the vacuumpump will engage at a level of 69 cm (27 in.) Hg. This operation is entirely automated. The AVM will continue mixing during theenti

17、re period. The unit will stop automatically when testing is complete (;11 minutes).min).9.3.10 After the unit has stopped mixing, remove the flask from mixing platform. Add a few drops of isopropyl alcohol or usea paper towel to remove bubbles if necessary to reduce error in reading the meniscus.9.3

18、.11 Fill the flask to the calibration mark with water.9.3.12 Determine the total mass of the flask with the sample and water filled to the calibration mark.9.3.13 Subtract the mass in step 9.3.7 from the mass in 9.3.12. Enter this value into the following equation to determine the filmcoefficient.Fi

19、lm Coefficient55214*X!20.11*X2! (1)D7172 143where:X = the difference between the values determined in 9.3.7 and 9.3.12, g.Film Coefficient55214*X!20.11*X2! (1)Where:X = the difference between the values determined in 9.3.7 and 9.3.12, g.9.4 Bulk Relative Density (Specific Gravity) and Percent Absorp

20、tion Determination:9.4.1 Turn the infrared unit on and allow it to complete the 30-minute warm up period.9.4.2 Place the empty, clean and completely dry bowl from the infrared unit on balance and record the mass of the bowl.9.4.3 Place 500 6 0.1 g of the sample into the bowl and record the mass of t

21、he bowl and sample.9.4.4 Calculate and record the dry aggregate weight by subtracting the mass in step 9.4.2 from 9.4.3.9.4.5 Place the bowl with the aggregate into the infrared unit, making certain that the notch in the front of the bowl fully engagesin the notch in the front of the metal mounting

22、plate. (Feel this with your finger at the bottom front of the bowl as placed.) Usethe ring on the bowl to securely fasten the bowl to the plate by pressing down and turning the ring 14 of a turn until tight. Next,place the top on the bowl and lightly press down to be certain it is engaged. The notch

23、 should be lined up in the front of the bowl.Then, close the lid to the infrared unit and latch in the front.9.4.6 Ensure that there is distilled water in the reservoir in the unit.9.4.7 Set the film coefficient to that determined in step 9.3.13. Press the enter button. The display will remind you t

24、o placesample in the unit. Press the start button. The system will automatically begin to determine the SSD point for the material. It willrun for 34 to 112 hours depending on the absorption of the material being tested.9.4.8 At the completion of the run, Press the OK button. Compare the film coeffi

25、cient on the display with the measured filmcoefficient for that material to be certain it was entered properly. Press the OK button.9.4.9 Open the unit; remove the lid to the bowl and store as directed by the manufacturer. Remove the bowl. Immediately placethe bowl on the balance and record the mass

26、. (See Note 7).)NOTE 7Be certain to determine the mass of the bowl immediately after removing the lid. This ensures that material is not allowed to dry.9.4.10 Determine the amount of water absorbed by subtracting the mass in step 9.4.3 from 9.4.9.10. Calculation10.1 Calculate the bulk relative densi

27、ty (specific gravity) on the basis of mass of oven-dry aggregate, as defined in Test MethodC128, as follows:Bulk relative densityspecific gravity!5A/A1B 2C1D! (2)where:A = mass of oven-dry specimen in air, g (9.4.4)B = mass of volumetric flask filled with water, g (9.2)C = mass of volumetric flask w

28、ith specimen and water to calibration mark, g (9.3.12)D = mass of water absorbed, g. (9.4.10)Bulk relative densityspecific gravity!5A/A1B 2C1D! (2)Where:A = mass of oven-dry specimen in air, g (9.4.4)B = mass of volumetric flask filled with water, g (9.2)C = mass of volumetric flask with specimen an

29、d water to calibration mark, g (9.3.12)D = mass of water absorbed, g. (9.4.10)10.2 Calculate the bulk relative density (specific gravity) on the basis of mass of saturated surface-dry aggregate, as follows:Bulk relative densityspecific gravity!saturated surface2dry basis!5 (3)A1D!/A1B 2C1D!Bulk rela

30、tive densityspecific gravity!saturated surface2dry basis!5 (3)A1D!/A1B 2C1D!10.3 Calculate the apparent relative density as follows:Apparent relative densityspecific gravity!5E/E1B 2C! (4)where:E = mass of oven-dry apparent specimen in air, g. (9.3.4)D7172 144Apparent relative densityspecific gravit

31、y!5E/E1B 2C! (4)Where:E = mass of oven-dry apparent specimen in air, g. (9.3.4)10.4 Calculate the percentage absorption, as defined in Terminology C125, as follows:Water Absorption,percent5D/A!3100 (5)Water Absorption,percent5D/A!3100 (5)11. Report11.1 Report the relative density (specific gravity)

32、results to the nearest 0.001 and absorption to the nearest 0.01 percent.%.12. Precision and Bias12.1 PrecisionThe estimates of precision of this test method (listed in Table 1) are based on results from a round-robinconducted by the National Center for Asphalt Technology.The Gsb for the samples rang

33、ed from approximately 2.300 to 3.000, the Gsa ranged from approximately 2.6500 to 3.000 andthe water absorption ranged from approximately 0.5 to 6.0 %. (See Note 8).)NOTE 8Results obtained using this test method may be different than those obtained using Test Method C128 and AASHTO T-84. These diffe

34、rencesmay also vary by material type.12.2 Biassince there is no accepted reference material suitable for determining the bias for this test method, no statement onbias is being made.13. Keywords13.1 absorption; aggregate; apparent density; apparent relative density; infrared; relative density; speci

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40、recisionStandardDeviation (1S)AAcceptable Range ofTwo Results (D2S)ASingle-Operator PrecisionBulk specific gravity (dry)B 0.0125 0.035Apparent specific gravityB 0.0066 0.019Water absorptionB, % 0.198 0.56Multilaboratory precisionBulk specific gravity (dry)B 0.0213 0.060Apparent specific gravityB 0.0

41、085 0.024Water absorptionB. % 0.324 0.92A These numbers represent, respectively, the (1S) and (D2S) limits as described in Practice C670. The precision estimates were obtained from a round-robin consistingof 12 labs with 12 different Thermolyne SSDetect units each testing 3 replicates of six materia

42、ls. The complete results of the round-robin are reported in:Prowell, B. D. and N. V. Baker, Evaluation of New Test Procedures for Determining the Bulk Specific Gravity of Fine Aggregate Using Automated Methods,TransportationResearch Record 1874 Transportation Research Board, National Academy of Sciences, Washington, D. C. 2004. Pp. 11-18.B The samples used for determination of the precision were chosen to represent a variety of different aggregate types; they included limestone, medium and high dustdiabase, slag, rounded sand and crushed gravel.D7172 145