ASTM D806-2000(2006) Standard Test Method for Cement Content of Hardened Soil-Cement Mixtures《硬化土-水泥混合料中水泥含量的标准试验方法》.pdf

1、Designation: D 806 00 (Reapproved 2006)Standard Test Method forCement Content of Hardened Soil-Cement Mixtures1This standard is issued under the fixed designation D 806; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l

2、ast 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. Scope*1.1 This test method covers the determination by chemicalanalysis of cement content of hardened soil-cement mixtures.1.2

3、All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D 6026.1.3 The values stated in SI units are to be regarded as thestandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its

4、 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. For specific hazardprecautions, see Section 6.2. Referenced Documents2.1 ASTM Standards:2C 125 Terminology Relatin

5、g to Concrete and ConcreteAggregatesC 219 Terminology Relating to Hydraulic CementD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 2901 Test Method for Cement Content of Freshly MixedSoil-CementD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspectio

6、n of Soil and Rockas Used in Engineering Design and ConstructionD 4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD 5982 Test Method for Determining Cement Content ofFresh Soil-Cement (Heat of Neutralization Met

7、hod)D 6026 Practice for Using Significant Digits in Geotechni-cal DataE 11 Specification for Wire Cloth and Sieves for TestingPurposesE 145 Specification for Gravity-Convection And Forced-Ventilation OvensE 832 Specification for Laboratory Filter Papers3. Terminology3.1 Definitions:3.1.1 Refer to Te

8、rminology D 653 for definitions of termsrelating to soil.3.1.2 Refer to Terminologies C 125 and C 219 for defini-tions of terms relating to cement.4. Significance and Use4.1 This test method determines cement content in mixturesof cement with soil or aggregate by chemical analysis. It wasdeveloped p

9、rimarily for testing samples for which a significantdegree of cement hydration or hardening has taken place. TestMethods D 2901 or D 5982 may be used for determiningcement content of freshly mixed soil-cement mixtures.4.2 This test method is based on determination by chemicalanalysis of the calcium

10、oxide (CaO) content of the sample. Themethod may not be applicable to soil-cement materials con-taining soils or aggregates which yield significant amounts ofdissolved calcium oxide (CaO) under the conditions of the test.NOTE 1The agency performing this test method can be evaluated inaccordance with

11、 Practice D 3740. Not withstanding statements on preci-sion and bias contained in this test method: the precision of this testmethod is dependent on the competence of the personnel performing it andthe suitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D 374

12、0 are generally considered capable of competentand objective testing. Users of this test method are cautioned thatcompliance with Practice D 3740 does not, in itself, ensure reliabletesting. Reliable testing depends on many factors; Practice D 3740provides a means of evaluating some of these factors

13、.5. Apparatus5.1 Analytical BalanceAn analytical balance conformingto the requirements of Class GP2 in Specification D 4753 andwith Class S weights.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.15 on Stabilizatio

14、n withAdmixtures.Current edition approved May 1, 2006. Published June 2006. Originallyapproved in 1944. Last previous edition approved in 2000 as D 806 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM

15、Standards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Filter PaperFilter pa

16、per including Whatman No. 1, 11and 15 cm in diameter; Whatman No. 41, 15 cm in diameter;and Whatman No. 2, 11 or 15 cm in diameter.5.3 Fifty-Millilitre-Pipet.5.4 Drying OvenThermostatically controlled, preferablyof the forced-air type, meeting the requirements of Specifica-tion E 145 and capable of

17、maintaining a uniform temperatureof 110 6 5C throughout the drying chamber.5.5 Miscellaneous ApparatusSupplementary equipment,such as electric ovens, hot plates, a small riffle, a No. 40- (425m-) sieve with bottom pan and cover, a cast iron mortar andpestle, and a ball mill if possible.6. Reagents6.

18、1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may b

19、eused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Potassium Permanganate, Standard Solution (0.1 N)Prepare and standardize a 0.1 N KMnO4solution.NOTE 2The use of a standard 0.1 N KMnO4soluti

20、on is not necessarywhen the samples are titrated in accordance with 8.9 and the results arecalculated in accordance with 9.2.6.3 Ammonium Nitrate SolutionDissolve 20 g of NH4NO3in 1L of distilled water.6.4 Hydrochloric Acid (1 + 3)Add 200 mL of HCl (sp gr1.19) to 600 mL of distilled water.6.5 Hydroc

21、hloric Acid (1 + 1)Add 25 mL of HCl (sp gr1.19) to 25 mL of distilled water.6.6 Nitric AcidSee Note 3.6.7 Ammonium Oxalate Solution (5 %)50 g of ammo-nium oxalate. (WarningIn addition to other precautions, thisis done by adding the acid, slowly while stirring, to the waterto avoid a sudden temperatu

22、re rise that could cause boiling andspattering of the acid solution.)6.8 Ammonium Hydroxide, NH4OH (sp gr 0.90).6.9 Sulfuric Acid (1 + 1)Add 500 mL H2SO4(sp gr 1.84)to 500 mL of distilled water.7. Samples7.1 Samples of the following shall be selected for the test:7.1.1 Raw Soil, representative of th

23、e soil phase of thesoil-cement mixture.7.1.2 Cement, representative of the cement phase of thesoil-cement mixture, and7.1.3 Soil-cement Mixture to be analyzed.7.2 The gross laboratory sample of each component shall beapproximately 200 g. This may be obtained by reducing thesample in bulk and, if nec

24、essary, in particle size through the useof drying, riffling and grinding processes.8. Procedure8.1 Dry 25 g of each of the samples in an oven to constantmass at 110 6 5C (230 6 9F) to remove free water. Reducethe samples to pass a No. 40- (425 m-) sieve.8.2 Using an analytical balance, prepare the f

25、ollowingamounts for each of the samples: raw soil, 5 g; soil-cementmixture, 5 g; and cement, 1 g. Place each of the weighedsamples in a 250-mL beaker. Add 50 mL of HCl (1 + 1) (Note3) to each sample, cover, and boil gently for 5 min on the hotplate.NOTE 3In the case of the cement sample, it is usual

26、ly preferable firstto add 40 mLof water and then stir to obtain a thorough mixture. Then add10 mL of HCl (sp gr 1.19) and boil gently just long enough to obtaindecomposition of the cement. Vigorous or extended boiling of soil orcement samples is seldom necessary, and often results in much slowerfilt

27、ration.8.3 Add 25 mL of hot water to the beakers, stir, allow tosettle momentarily, and then decant the contents through aWhatman No. 1 filter paper (Note 4), preferably 15 cm indiameter. The filtrate should be received in a 250-mL volumet-ric flask. When the liquid has passed through the filter pap

28、er,wash the residue once by decantation, using hot water; thentransfer it to the filter, using a stream of hot water. The beakershould be rapidly policed, the loosened material being trans-ferred to the filter paper. The material on the filter should thenbe washed an additional four times, each wash

29、ing consisting of10 to 15 mL of hot water directed in a stream from the washbottle. Very small amounts of residue will occasionally passthrough the filter. These ordinarily may be disregarded.NOTE 4In the case of the soil and soil-cement samples, the bulk of theresidue sometimes slows filtration app

30、reciably. No difficulty is usuallyencountered from cement samples, and, as a rule, soil samples may befiltered and washed in less than 30 min. Some soil-cement mixturesrequire more time, but, if this period exceeds 1 h, subsequent filtration insimilar cases may be more rapid if a No. 41 paper is sub

31、stituted for the No.1 paper. Slow filtration in such cases is generally caused by excessiveboiling, resulting in gelation of the silica, which materially retardsfiltration.8.4 When washing has been completed, discard the filter,and dilute the filtrate in the volumetric flask to 250 mL withcold water

32、. The temperature of the solution should be near thecalibration point of the flask. Agitate the flask to mix thecontents thoroughly, then remove a 50-mL aliquot and transferto the original 250-mL beaker (8.2), using a 50-mL pipet.Dilute to 100 mL. Make the solution slightly ammoniacal(Note 5), boil

33、1 to 2 min, and allow the hydroxides to settle.NOTE 5If the samples contain ferrous iron it is desirable to add a fewdrops of HNO3before precipitation of the hydroxides.8.5 Filter the hydroxides through an 11-cm Whatman No. 1(or No. 41) filter paper, receiving the filtrate in the 600-mLbeaker. Wash

34、the original 250-mL beaker into the filter oncewith a stream of hot NH4NO3solution (20 g/L), and follow bywashing the hydroxide precipitate once or twice with hotNH4NO3solution (20 g/L). Set the filtrate aside, and place theoriginal beaker under the funnel. Perforate the paper with a rod3“Reagent Ch

35、emicals, American Chemical Society Specifications,” AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see “Reagent Chemicals and Standards,”by Joseph Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesP

36、harmacopeia.”D 806 00 (2006)2(Note 6), and wash the hydroxides down into the originalbeaker, using a stream of hot NH4NO3solution (20 g/L) toremove most of the precipitate from the filter paper. Treat thepaper with 20 mLof hot HCl (1 + 3), directing the acid over thepaper with a glass rod. Wash the

37、paper several times with hotwater, and then discard the paper. Dilute the solution to 75 mL.NOTE 6Instead of perforating the filter paper, the paper and precipi-tate may be transferred to the original beaker, the hydroxides dissolvedwith 20 mL of hot HCl (1 + 3) and diluted to 75 mL with water, and

38、theprocedure continued as described in 8.6. In this case, the reprecipitatedhydroxides and pulp are subsequently removed simultaneously.8.6 Make the solution slightly ammoniacal and boil 1 to 2min. Allow the precipitate to settle, then decant through aWhatman No. 1 paper as before, receiving the fil

39、trate in the600-mL beaker previously set aside (8.5). Wash and police thebeaker in which precipitation took place, finally washing theprecipitate on the filter three or four times with NH4NO3solution (20 g/L). Discard the hydroxide precipitate. Add 2 mLof NH4OH (sp gr 0.90) to the filtrate, which wi

40、ll now have avolume of 250 to 350 mL. Heat the solution to boiling and add10 mL of hot saturated ammonium oxalate solution. Keep themixture near boiling until precipitate becomes granular; thenset aside on a warm hot plate for 30 min or more. Beforefiltering off the calcium oxalate, verify completen

41、ess of pre-cipitation, (Note 7) and make sure that a slight excess ofNH4OH is present. Filter the mixture through an 11-cm or15-cm Whatman No. 2 filter paper, or if preferred a WhatmanNo. 42 paper, making sure that all the precipitate is beingretained. Thoroughly clean with a rubber policeman the be

42、akerin which precipitation took place, and transfer the contents tothe filter with a stream of hot water. Wash the filter eight to tentimes with hot water (not over 75 mL) (Note 8), using a streamfrom the wash bottle.NOTE 7The calcium oxalate precipitation is sometimes not completeand this results i

43、n low CaO values. The precipitation operation must becarried out with thoroughness and care.NOTE 8The filter may be washed four times each with NH4OH(2 + 98) and hot water, in the order stated.8.7 Carefully open the filter paper and wash the precipitateinto the beaker in which the precipitation was

44、effected. Diluteto 200 mL and add 10 mL of H2SO4(1 + 1). Heat the solutionjust short of boiling, and titrate it with the standard KMnO4solution (Note 9) to a persistent pink color. Add the filter paperand macerate it. Continue the titration slowly until the pinkcolor persists for 10 s.NOTE 9The temp

45、erature of the standard KMnO4solution should notvary from its standardization temperature so much as to cause a seriouserror in the determination of CaO. At ordinary room temperatures thevolume of pure water changes to the extent of 0.01 to 0.04 % for eachdegree Celsius, depending on the temperature

46、.8.8 BlankMake a blank determination, following thesame procedure and using the same amounts of all reagents.8.9 Alternative Titration ProcedureTitrate as described in8.7, except that the KMnO4solution need not be a standard 0.1N solution, but the same solution shall be used in titrating allthe comp

47、onents. Omit the blank determination described in8.8.9. Calculation9.1 Calculate the cement content of the soil-cement mixtureas follows:9.1.1 When the determination has been completed in accor-dance with 8.7 and 8.8:9.1.1.1 Calculate the percentages of CaO in the soil, thecement, and the soil-cemen

48、t mixture as follows:CaO, % 5 A 2 B!C 3 0.028!/D 3 100 (1)where:A = KMnO4solution required for titration of thesample, mL,B = KMnO4solution required for titration of the blank,mL,C = normality of the KMnO4solution,D = sample represented by the aliquot titrated (Note 9),g, and0.028 = CaO equivalent o

49、f 1 mL of 1.0 N KMnO4solution.9.1.1.2 Calculate the percent cement by mass of soil asfollows (Note 11):Cement, % 5 G 2 F!/E 2 F!# 3 100 (2)where:E = CaO in cement, %,F = CaO in raw soil, %, andG = CaO in soil-cement mixture,% .NOTE 10The aliquots titrated are equivalent to1gofsoil orsoil-cement and 0.2 g of cement.NOTE 11The value for percentage by mass of soil obtained inaccordance with 9.1 or 9.2 is in terms of hydrated cement. Such valuesmay be converted to an approximate equivalent of dry cement bymultiplying them by the factor 1.04.9.2 When