ASTM D4792-2000(2006) Standard Test Method for Potential Expansion of Aggregates from Hydration Reactions《从水化反应中对集料膨胀的标准试验方法》.pdf

1、Designation: D 4792 00 (Reapproved 2006)Standard Test Method forPotential Expansion of Aggregates from HydrationReactions1This standard is issued under the fixed designation D 4792; 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 test method covers the determination of potentialvolume expansion of dense graded compacted aggregate

3、s thatcontain components susceptible to hydration and consequentvolume increase, such as the free calcium and magnesiumoxides that occur in some industrial by-products.1.2 The values stated in SI units are to be regarded as thestandard. The inch-pound units in parentheses are for informa-tion purpos

4、es only.1.3 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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Refe

5、renced Documents2.1 ASTM Standards:2C 702 Practice for Reducing Samples of Aggregate toTesting SizeD75 Practice for Sampling AggregatesD 698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D 1883 Test Method for CBR (California Bear

6、ing Ratio) ofLaboratory-Compacted SoilsD 2940 Specification for Graded Aggregate Material ForBases or Subbases for Highways or Airports3. Summary of Test Method3.1 This test method consists of measuring the volumeexpansion of compacted specimens following the generalprocedures of Test Method D 1883.

7、 Compaction is based onmaximum density determination using Test Methods D 698.Toaccelerate the hydration reaction, specimens are stored in waterat 70 6 3C (158 6 5F) for a minimum of 7 days.4. Significance and Use4.1 This test method provides a procedure for determiningthe compliance of steel slags

8、and other materials with specifi-cations, such as Specification D 2940, that limit permissibleexpansion of base and subbase aggregates containing compo-nents subject to hydration.4.2 This test method can also be used to evaluate theeffectiveness of aging or other treatments for reducing theexpansive

9、 potential of such materials.4.3 Test results have not been correlated with field perfor-mance, and values obtained do not necessarily indicate expan-sion that may occur in service conditions.5. Apparatus5.1 Molds, Spacer Disks, Expansion Measuring Apparatus,Stainless Steel Weights, and Dial Gages c

10、onforming to therequirements of Test Method D 1883.5.2 Mixing Bowl, Straight-Edge, Scale, Filter Paper,Dishes, etc. as required in Test Methods D 698 and D 1883.5.3 Water Storage FacilityA water bath controlled at 7063C (158 6 5F) or suitable tanks or buckets for submersion ofthe test specimens in a

11、n oven controlled so as to maintain thatwater temperature.6. Sampling6.1 To determine compliance with specifications, take fieldsamples in accordance with Practice D75or the requirementsof the project specifications.6.2 Take samples for research or general evaluation pur-poses in a manner appropriat

12、e for the materials and purposesinvolved.6.3 Keep samples at field moisture content until the time ofthe test by sealing in water-tight containers or plastic bags.7. Preparation of Sample7.1 Reduce the field sample to testing size in accordancewith Practice C 702, obtaining two 18-kg (40-lb) portion

13、s.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved Dec. 1, 2006. Published December 2006. Originallyapproved in 1988. Last previous edition approved in in 2

14、000 as D 4792 - 002For 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 onthe ASTM website.1Copyright ASTM International, 100 Barr Har

15、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Pass the samples through the 19.0-mm (34-in.) and4.75-mm (No. 4) sieves. If 10 % or more is retained on the19.0-mm (34-in.) sieve proceed to 7.2.1 for oversize correction.7.2.1 Pass the material through a 75-mm (3-in.) sieve

16、.Discard the material retained on the 75-mm (3-in.) sieve. Thematerial passing the 75-mm (3-in.) sieve and retained on the19-mm (34-in.) sieve shall be replaced with an equal amount ofmaterial passing a 19-mm (34-in.) sieve and retained on a4.75-mm (No. 4) sieve. The material for replacement shall b

17、etaken from an unused portion of the sample.7.3 Reseal one of the sample portions to maintain the fieldmoisture and retain for expansion test specimens. Test the otherportion for maximum density and optimum moisture.8. Moisture-Density Relationship8.1 Determine the moisture-density relationship in a

18、ccor-dance with Test Method D 698, Moisture Preparation Method,except that the mold specified in Test Method D 1883 shall beused.8.2 Use Method B or C depending upon the gradation of thesample, with oversize corrections as recommended in 7.2.1.9. Expansion Test9.1 Prepare three expansion test specim

19、ens from the sampleset aside for this purpose, following the procedure in TestMethod D 1883 for specimens to be soaked.9.2 After placing the adjustable stem and perforated plate onthe compacted specimens in the molds, add weights to producea surcharge of 4.54 kg (10 lb), and submerge the molds andwe

20、ights in water at 70 6 3C (158 6 5F). Allow free accessof water to the top and bottom of the specimens, and maintainthe temperature at 70 6 3C (158 6 5F) for the testing period.NOTE 1The molds should be well coated with a rust preventative,such as 10W motor oil, whether they are constructed of corro

21、sion-resistantmetal or not.NOTE 2Excessive (more than 2.5 cm) evaporation of the bath watermay necessitate the use of a cover over the water bath. This will reducerequired water addition and variations in bath temperature.9.3 After the specimens have been immersed in the hotwater for 30 minutes to a

22、llow for thermal expansion of the testapparatus, take the initial dial gage measurements. These arethe base readings from which the expansion will be deter-mined.9.4 Add heated water daily to keep the test specimens fullysubmerged. Make daily dial gage readings of specimen heightsfor a period of sev

23、en days, allowing at least 2 h to elapsebetween the addition of water and the measurement.9.5 Measure and record the temperature of the water on acontinuous or daily basis.10. Calculation10.1 Percent Expansion (Volumetric)Calculate the per-cent expansion at each days measurement by dividing thediffe

24、rence between the daily dial gage reading and the basereading by the initial specimen height (116.43 mm (4.584 in.)and multiplying by 100.10.2 Rate of ExpansionPlot the percent expansion (y-axis) versus the time in days (x-axis).NOTE 3Seven days is usually adequate to evaluate probable expan-sive be

25、havior, with a pronounced decrease in the rate prior to this time. Ifthe expansion rate has not dropped by seven days, the test may becontinued to obtain additional data.11. Report11.1 The report shall include the following:11.1.1 Identification of the sample by source and date,11.1.2 Moisture conte

26、nt and percentages of material re-tained on the 19.0 mm (34-in.) and 4.75-mm (No. 4) sieves asreceived,11.1.3 Optimum moisture content, maximum density, themethod used (B or C) and oversize correction made from TestMethods D 698,11.1.4 Expansion data for each specimen and the averagefor three specim

27、ens from 10.1,11.1.5 The plot of the rate-of-expansion for each specimenand the average of three from 10.2, and11.1.6 A continuous or daily record of the temperature ofthe water bath.12. Precision and Bias312.1 This data was obtained in a study of variability usingfour and six laboratories and thus

28、should be regarded aspreliminary.12.1.1 Expansion of less than 0.5 %The average multi-laboratory coefficient of variation, when testing one specimen,has been found to be 25 %, therefore the difference in resultsreported by different laboratories on samples of the samematerial should not differ by mo

29、re than 71 % of their average,nineteen times in twenty.12.1.2 Expansion of more than 0.5 %The average multi-laboratory coefficient of variation, when testing one specimen,has been found to be 18 %, therefore the difference in resultsreported by different laboratories on samples of the samematerial s

30、hould not differ by more than 51 % of their average,nineteen times in twenty.13. Keywords13.1 aggregates; expansion; hydration reaction3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D041018.D 4792 00 (2006)2ASTM International

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33、ressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting 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

34、 the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, 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).D 4792 00 (2006)3