ASTM C151 C151M-2015 Standard Test Method for Autoclave Expansion of Hydraulic Cement《水硬性水泥热压膨胀的标准试验方法》.pdf

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1、Designation: C151/C151M 15Standard Test Method forAutoclave Expansion of Hydraulic Cement1This standard is issued under the fixed designation C151/C151M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A

2、number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers determination of the autoclaveexpansion of hydraulic cement by means of a test on a neatcement specimen.1.2 Th

3、e values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the st

4、andard.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. For spe

5、cificprecaution statements, see the section on Safety Precautions.2. Referenced Documents2.1 ASTM Standards:2C187 Test Method for Amount of Water Required for Nor-mal Consistency of Hydraulic Cement PasteC305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic Consistency

6、C490 Practice for Use of Apparatus for the Determination ofLength Change of Hardened Cement Paste, Mortar, andConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC856 Practice for Petrographic Examinati

7、on of HardenedConcreteC1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsC1157 Performance Specification for Hydraulic Cement3. Significance and Use3.1 The autoclave expansion test provides an index ofpotential delay

8、ed expansion caused by the hydration of CaO orMgO, or both, when present in hydraulic cement.34. Interferences4.1 Pozzolans containing fine-grained quartz have beenreported to cause excessive expansion under autoclave testconditions due to alkali-silica reaction that will not occur undernormal servi

9、ce conditions.4When excessive expansion of pastecontaining pozzolans occurs, it is recommended that thespecimens be examined (see Practice C856) for evidence ofalkali-silica reaction (Note 1).NOTE 1If the excessive expansion has resulted from alkali-silicareaction under autoclave conditions, the poz

10、zolan can be evaluated foralkali reactivity using the procedure described in Performance Specifica-tion C1157.5. Apparatus5.1 Weighing Devices and Weights, for determining themass of materials conforming to the requirements of Specifi-cation C1005.5.2 Glass Graduates, 200 or 250-mLcapacity, and conf

11、orm-ing to the requirements of Practice C490.5.3 Molds, conforming to the requirements of Practice C490for test specimens used in the determination of length changeof cement paste.5.4 Flat Trowel, conforming to the requirements of TestMethod C187.5.5 Autoclave, consisting of a high-pressure steam ve

12、sselprovided with a thermometer well. The autoclave shall beequipped with automatic controls and either a rupture disk witha bursting pressure of 2.4 MPa 350 psi 6 5 % or a safetyvalve that actuates at this pressure. In addition, the autoclaveshall be equipped with a vent valve to allow the escape o

13、f air1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.31 on Volume Change.Current edition approved Jan. 1, 2015. Published January 2015. Originallyapproved in 1940. Last previous edition approved in 2009 as C151/C151M 09.

14、DOI: 10.1520/C0151_C0151M-15.2For 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.3Gonnerman, H. F., Lerch, W. and

15、 Whiteside, T. M., “Investigations of theHydration Expansion Characteristics of Portland Cements,” Portland CementAssociation Research Department Bulletin 45, pp. 1168, 1953.4Wang, H., “Autoclave Soundness Test Mischaracterizes Cement-Fly AshBlends by Introducing Alkali-Quartz Reaction,” Cement, Con

16、crete, and Aggregates,Vol 24, No. 2, pp. 6872, 2002.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1during the early part of the heating period and to release anysteam p

17、ressure remaining at the end of the cooling period. Thepressure gauge shall have a nominal capacity of 4.0 MPa600 psi, a dial with a nominal diameter of 115 mm 412 in.and shall be graduated from 0 to 4.0 MPa 0 to 600 psi withscale divisions not exceeding 0.03 MPa 5 psi. The error in thegauge shall n

18、ot exceed 6 0.02 MPa 6 3 psi at the operatingpressure of 2 MPa 295 psi. The capacity of the heating unitshall be such that with maximum load (water plus specimens)the pressure of the saturated steam in the autoclave may beraised to a gauge pressure of 2 MPa 295 psi in 45 to 75 minfrom the time the h

19、eat is turned on. The automatic control shallbe capable of maintaining the gauge pressure at 2 6 0.07 MPa295 6 10 psi for at least 3 h. A gauge pressure of 2 60.07 MPa 295 6 10 psi corresponds to a temperature of 2166 2C 420 6 3F. The autoclave shall be designed to permitthe gauge pressure to drop f

20、rom 2 MPa to less than 0.07 MPa295 psi to less than 10 psi in 112 h after the heat supply hasbeen shut off.5.5.1 Rupture DiskThe rupture disk shall be made of amaterial having a tensile strength that is relatively insensitiveto temperature in the range 20 to 216C 68 to 420F and thatis electrochemica

21、lly compatible with the pipe leading to it andto its holder.55.6 Length ComparatorThe comparator used for measur-ing length change of specimens shall conform to the require-ments of Practice C490.6. Temperature and Humidity6.1 Molding RoomMaintain the temperature of the mold-ing room, dry materials

22、and mixing water, and the relativehumidity of the molding room within the limits of PracticeC490.6.2 Moist Storage FacilitiesMaintain the temperature andhumidity of the moist storage facilities to the requirements ofSpecification C511.7. Safety Precautions7.1 The pressure gauge shall have a capacity

23、 of 4.0 MPa600 psi. A gauge with too small or too large a capacity maybe a hazard, since for pressure above the specified maximumworking pressure, with a smaller capacity gauge, the pressuremay be off scale, and with a larger capacity gauge, the arc ofmovement may be too small to invite attention. T

24、he operatorshall be sure the gauge hand has not passed the maximumgraduation on the scale.7.2 Test the pressure gauge for proper operation.Always usea thermometer together with the pressure gauge, so as toprovide a means of detecting any failure of the pressure gaugeto operate properly, and to indic

25、ate any unusual condition.7.3 Maintain the automatic control in proper working orderat all times.7.4 Set the safety valve to relieve the pressure at about 6 to10 % above the maximum of 2.1 MPa 305 psi specified inthis test method, that is, at about 2.3 MPa 330 psi. Unless themanufacturer has given s

26、pecific instructions as to maintenanceof the safety valve, test the valve twice each year.6Test with agauge testing device, or by adjusting the automatic controls toallow the autoclave to reach a pressure of about 2.3 MPa330 psi, at which pressure the safety valve will either open orbe adjusted to o

27、pen. Direct the safety valve discharge awayfrom the operator.NOTE 2Unexpected combinations of conditions may occur. Forexample, in one case the automatic control had failed, the safety valve hadbecome stuck, and the gauge hand, which at first glance appeared to be atabout zero, had passed the maximu

28、m graduation and had come to stop onthe wrong side of the pin. This condition of the gauge was finally detectedand the pressure, then of an unknown magnitude, was released beforefailure could occur in the apparatus.7.5 Wear heavy leather work gloves to prevent burning ofthe hands when removing the t

29、op of the autoclave at the end ofthe test. Direct the vent valve away from the operator. Whenremoving the autoclave lid, tilt it so that any steam escapingfrom beneath the lid will be discharged away from the operator.Care shall be taken to avoid scalding by any liquid that mayhave been used in the

30、autoclave well.7.6 The operator shall be made aware that for many auto-clave pressure gauges the return of the gauge hand to the initialrest or starting point does not necessarily indicate zero pressurewithin the autoclave; there may then still remain an appreciabledangerous pressure. Procedures in

31、11.2 shall be followed.8. Number of Test Specimens8.1 Make at least one test specimen.9. Preparation of Specimen Molds9.1 Prepare the specimen molds in accordance with therequirements of Practice C490 except that molds need not besealed.10. Preparation of Test Specimens10.1 Mixing Cement PastePrepar

32、e the standard batchconsisting of 650 g of cement and sufficient water to give apaste of normal consistency in accordance with the proceduredescribed in Test Method C187. Mix this batch in accordancewith the procedure described in Practice C305. Both a time ofsetting specimen and an autoclave bar ma

33、y be made from thesame batch. If the paste to be used for time of setting is thepaste sample already used to determine normal consistency,then the autoclave bar may be prepared immediately from theremainder of the batch.10.2 Molding SpecimensImmediately following prepara-tion of the time of setting

34、specimen or completion of mixing,mold the test specimen in two approximately equal layers, eachlayer being compacted with the thumbs or forefingers bypressing the paste into the corners, around the gauge studs, andalong the surface of the mold until a homogeneous specimen isobtained. Compact the top

35、 layer, cut off the paste flush with thetop of the mold with a thin-edged trowel, and smooth the5A list of suppliers of autoclave rupture disks and gaskets is maintained atASTM Headquarters.6A list of facilities for testing autoclave safety valves is maintained at ASTMHeadquarters.C151/C151M 152surf

36、ace with a few strokes of the flat trowel. During theoperations of mixing and molding, protect the hands withrubber gloves.10.3 Storage of Test SpecimensAfter filling the mold,place it in the moist closet or moist room. Store the specimensin the molds in the moist enclosure for at least 20 h; if rem

37、ovedfrom the molds before 24 h, they shall be kept in the moistcloset or moist room until time of test.11. Procedure11.1 At 24 h 6 30 min after molding, remove the specimensfrom the moist atmosphere, immediately obtain a lengthcomparator reading for each specimen, and place in theautoclave at room t

38、emperature in a rack so that all sides of thespecimen will be exposed to saturated steam. The autoclaveshall contain enough water, at an initial temperature of 20 to28C 68 to 82F, to maintain an atmosphere of saturatedsteam vapor during the entire test. Ordinarily 7 to 10 % of thevolume of the autoc

39、lave should be occupied by the water.11.2 To permit air to escape from the autoclave during theearly portion of the heating period, leave the vent valve openuntil steam begins to escape. (WarningSee the section onSafety Precautions). Close the valve and raise the temperatureof the autoclave at a rat

40、e that will bring the gauge pressure ofthe steam to 2 MPa 295 psi in 45 to 75 min from the time theheat is turned on. Maintain the 2 6 0.07 MPa 295 6 10 psipressure for 3 h. At the end of the 3-h period, shut off the heatsupply and cool the autoclave at such a rate that the pressurewill be less than

41、 0.07 MPa 10 psi at the end of 112 h. At theend of the 112-h period, slowly release any remaining pressureby partially opening the vent valve until atmospheric pressureis attained. Then open the autoclave and place the testspecimen in water at a temperature above 90C 194F. Coolthe water surrounding

42、the bars at a uniform rate by adding coldwater so that the temperature of the water will be lowered to23C 74F in 15 min. Maintain the water surrounding thespecimens at 23C 74F for an additional 15 min; then,remove one specimen at a time from the water, blot the pins,but not the specimen, and obtain

43、a length comparator reading.12. Calculation12.1 Calculate the change in length of the test specimen bysubtracting the length comparator reading before autoclavingfrom that after autoclaving, and report as percent of effectivegauge length to the nearest 0.01 %. Report the percentage ofincrease in len

44、gth as the autoclave expansion. Indicate adecrease in length by a minus sign prefixed to the percentvalue.13. Precision and Bias13.1 PrecisionThe single-operator (within-laboratory)standard deviation has been found to be 0.024 % throughoutthe range of 0.11 % to 0.94 % expansions. Therefore, results

45、oftwo properly conducted tests by the same operator for expan-sions of similar batches should not differ from each other bymore than 0.07 % expansion. The multi-laboratory (betweenlaboratory) standard deviation has been found to be 0.030 %throughout the range of 0.11 % to 0.94 % expansions.Therefore

46、, results of two properly conducted tests from twodifferent laboratories for expansions of similar batches shouldnot differ from each other by more than 0.09 % expansion.13.2 BiasSince there is no accepted reference materialsuitable for determining bias, bias has not been determined.14. Keywords14.1

47、 autoclave; autoclave expansion; expansion; hydrauliccement; soundnessFor additional useful information on details of cement test methods, reference may be made to the “Manual of CementTesting,” which appears in the Annual Book of ASTM Standards, Vol 04.01.SUMMARY OF CHANGESCommittee C01 has identif

48、ied the location of selected changes to this standard since the last issue(C151/C151M 09) that may impact the use of this standard. (Approved Jan. 1, 2015.)(1) Revised subsections 5.5 and 7.6.C151/C151M 153ASTM International takes no position respecting the validity of any patent rights asserted in

49、connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standard