1、Designation: D806 11Standard Test Method forCement Content of Hardened Soil-Cement Mixtures1This standard is issued under the fixed designation D806; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 All observed and calc
3、ulated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety con
4、cerns, 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. For specific hazardprecautions, see Section 6.2. Referenced Documents2.1 ASTM St
5、andards:2C125 Terminology Relating to Concrete and Concrete Ag-gregatesC219 Terminology Relating to Hydraulic CementD653 Terminology Relating to Soil, Rock, and ContainedFluidsD2901 Test Method for Cement Content of Freshly MixedSoil-CementD3740 Practice for Minimum Requirements for AgenciesEngaged
6、in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD5982 Test Method for Determining Cement Content ofFresh Soil-Cement (H
7、eat of Neutralization Method)D6026 Practice for Using Significant Digits in GeotechnicalDataE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE145 Specification for Gravity-Convection and Forced-Ventilation OvensE832 Specification for Laboratory Filter Papers3. Terminology3.1 Definitio
8、ns:3.1.1 Refer to Terminology D653 for definitions of termsrelating to soil.3.1.2 Refer to Terminologies C125 and C219 for definitionsof 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
9、 wasdeveloped primarily for testing samples for which a significantdegree of cement hydration or hardening has taken place. TestMethods D2901 or D5982 may be used for determining cementcontent of freshly mixed soil-cement mixtures.4.2 This test method is based on determination by chemicalanalysis of
10、 the calcium 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 inac
11、cordance with Practice D3740. 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 Pr
12、actice D3740 are generally considered capable of competentand objective testing. Users of this test method are cautioned thatcompliance with Practice D3740 does not, in itself, ensure reliable testing.Reliable testing depends on many factors; Practice D3740 provides ameans of evaluating some of thes
13、e factors.5. Apparatus5.1 Analytical BalanceAn analytical balance conformingto the requirements of Class GP2 in Specification D4753 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 Stab
14、ilization WithAdmixtures.Current edition approved Nov. 1, 2011. Published January 2012. Originallyapproved in 1944. Last previous edition approved in 2006 as D80600(2006). DOI:10.1520/D0806-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
15、rviceastm.org. For Annual Book of ASTMStandards 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, U
16、nited States.5.2 Filter PaperFilter paper 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 o
17、f Specifica-tion E145 and capable of maintaining a uniform temperature of110 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
18、a ball mill if possible.6. Reagents6.1 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 specificati
19、ons are available.3Other grades may beused, 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 a 0.1 N KMnO4solution and standardize againstp
20、rimary standard grade oxalic acid, sodium oxalate or iron (II)ammonium sulfate hexahydrate.NOTE 2The use of a standard 0.1 N KMnO4solution is not necessarywhen the samples are titrated in accordance with 8.9 and the results arecalculated in accordance with 9.2. However, the actual reagent concen-tra
21、tion must be determined by titration against primary standard gradeoxalic acid, sodium oxalate or iron (II) ammonium sulfate hexahydrate.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 wate
22、r.6.5 Hydrochloric 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 sudd
23、en temperature 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, represen
24、tative of the 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
25、 and, if necessary, 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, p
26、repare the followingamounts 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,
27、 it is usually preferable firstto add 25 mLof water and then stir to obtain a thorough mixture. Then add25 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 muc
28、h slowerfiltration.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 th
29、e filter paper,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 time
30、s, each washing 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 fi
31、ltration appreciably. 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
32、paper is substituted 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 wi
33、thcold water. 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(No
34、te 5) by dropwise addition of ammonium hydroxide, boil 1to 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. Also, pH paper canbe used to assure that enough ammonium hydroxide has been
35、added.8.5 Filter the hydroxides through an 11-cm Whatman No. 1(or No. 41) filter paper, receiving the filtrate in the 600-mL3“Reagent Chemicals, American Chemical Society Specifications,” AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American C
36、hemical Society, see “Reagent Chemicals and Standards,”by Joseph Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacopeia.”D806 112beaker. Wash the original 250-mL beaker into the filter oncewith a stream of hot NH4NO3solution (20 g/L), and follow bywashing the hydroxide pr
37、ecipitate once or twice with hotNH4NO3solution (20 g/L). Set the filtrate aside, and place theoriginal beaker under the funnel. Perforate the paper with a rod(Note 6), and wash the hydroxides down into the originalbeaker, using a stream of hot NH4NO3solution (20 g/L) toremove most of the precipitate
38、 from the filter paper. Treat thepaper with 20 mLof hot HCl (1 + 3), directing the acid over thepaper with a glass rod. Wash the 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 b
39、e transferred to the original beaker, the hydroxides dissolvedwith 20 mL of hot HCl (1 + 3) and diluted to 75 mL with water, and theprocedure continued as described in 8.6. In this case, the reprecipitatedhydroxides and pulp are subsequently removed simultaneously.8.6 Make the solution slightly ammo
40、niacal and boil 1 to 2min. Allow the precipitate to settle, then decant through aWhatman No. 1 paper as before, receiving the filtrate 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 fo
41、ur times with NH4NO3solution (20 g/L). Discard the hydroxide precipitate. Add 2 mLof NH4OH (sp gr 0.90) to the filtrate, which will 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
42、becomes granular; thenset aside on a warm hot plate for 30 min or more. Beforefiltering off the calcium oxalate, verify completeness 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 prefer
43、red a WhatmanNo. 42 paper, making sure that all the precipitate is beingretained. Thoroughly clean with a rubber policeman the beakerin 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)
44、 (Note 8), using a streamfrom the wash bottle.NOTE 7The calcium oxalate precipitation is sometimes not completeand this results in 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
45、, in the order stated.8.7 Carefully open the filter paper and wash the precipitateinto the beaker in which the precipitation was 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 pi
46、nk color. Add the filter paperand macerate it. Continue the titration slowly until the pinkcolor persists for 10 s.NOTE 9The temperature 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
47、temperatures thevolume of pure water changes to the extent of 0.01 to 0.04 % for eachdegree Celsius, depending on the temperature.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,
48、 except that the KMnO4solution need not be a standard 0.1N solution, but the same solution shall be used in titrating allthe components. 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 b
49、een 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-cement 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 (Note10), g, and0.028 = CaO equivalent of 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
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