1、Designation: C151/C151M 18Standard 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 expansionof a hardened cement paste when exposed to the autoclaveconditions in this metho
3、d.1.2 The 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-conformancewit
4、h the standard.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, health, and environmental practices and deter-mine the applicability of regulatory limitatio
5、ns prior to use.For specific precaution statements, see the section on SafetyPrecautions.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards
6、, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.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 C
7、ementPastes and Mortars of Plastic ConsistencyC490/C490M Practice for Use of Apparatus for the Deter-mination of Length Change of Hardened Cement Paste,Mortar, and ConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements
8、 and ConcretesC856 Practice for Petrographic Examination of HardenedConcreteC1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsC1157/C1157M Performance Specification for HydraulicCement3. Significance and Use3.1 The
9、autoclave expansion test provides an index ofpotential delayed 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
10、alkali-silica reaction that will not occur undernormal service 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 fr
11、om alkali-silicareaction under autoclave conditions, the pozzolan can be evaluated foralkali reactivity using the procedure described in Performance Specifica-tion C1157/C1157M.5. Apparatus5.1 Weighing Devices and Weights, for determining themass of materials conforming to the requirements of Specif
12、i-cation C1005.5.2 Glass Graduates, 200 or 250-mLcapacity, and conform-ing to the requirements of Practice C490/C490M.5.3 Molds, conforming to the requirements of PracticeC490/C490M for test specimens used in the determination oflength change of cement paste.1This test method is under the jurisdicti
13、on of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.31 on Volume Change.Current edition approved April 1, 2018. Published April 2018. Originallyapproved in 1940. Last previous edition approved in 2016 as C151/C151M 16.DOI: 10.1520/C0151_C0151M-18.2For referenced AS
14、TM 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 Whiteside, T. M., “Investigations of theHydrat
15、ion 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, Concrete, and Aggregates,Vol 24, No. 2, pp. 6872,
16、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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization
17、 established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.4 Flat Trowel, conforming to the requirements of TestMethod C187.5.5 Autoclave, consisting of a h
18、igh-pressure steam vesselprovided 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
19、to allow the escape of airduring the early part of the heating period and to release anysteam pressure 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 M
20、Pa 0 to 600 psi withscale divisions not exceeding 0.03 MPa 5 psi. The error in thegauge shall not 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
21、 autoclave may beraised to a gauge pressure of 2 MPa 295 psi in 45 to 75 minfrom the time the heat 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 tempera
22、ture of 2166 2C 420 6 3F. The autoclave shall be designed to permitthe gauge pressure to drop from 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 re
23、latively insensitiveto temperature in the range 20 to 216C 68 to 420F and thatis electrochemically compatible with the pipe leading to it andto its holder.5.6 Length ComparatorThe comparator used for measur-ing length change of specimens shall conform to the require-ments of Practice C490/C490M.6. T
24、emperature and Humidity6.1 Molding RoomMaintain the temperature of the mold-ing room, dry materials and mixing water, and the relativehumidity of the molding room within the limits of PracticeC490/C490M.6.2 Moist Storage FacilitiesMaintain the temperature andhumidity of the moist storage facilities
25、to the requirements ofSpecification C511.7. Safety Precautions7.1 The pressure gauge shall have a capacity 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
26、be off scale, and with a larger capacity gauge, the arc ofmovement may be too small to invite attention. The 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 gaug
27、e, so as toprovide a means of detecting any failure of the pressure gaugeto operate properly, and to indicate 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 3
28、05 psi specified inthis test method, that is, at about 2.3 MPa 330 psi. Unless themanufacturer has given specific instructions as to maintenanceof the safety valve, test the valve twice each year. Test with agauge testing device, or by adjusting the automatic controls toallow the autoclave to reach
29、a pressure of about 2.3 MPa330 psi, at which pressure the safety valve will either open orbe adjusted to open. 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 had
30、become stuck, and the gauge hand, which at first glance appeared to be atabout zero, had passed the maximum 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 oc
31、cur in the apparatus.7.5 Wear heavy leather work gloves to prevent burning ofthe hands when removing the top 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
32、 away from the operator.Care shall be taken to avoid scalding by any liquid that mayhave been used in the 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
33、pressurewithin the autoclave; there may then still remain an appreciabledangerous pressure. Procedures in 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 Practic
34、e C490/C490M except that molds neednot be sealed.10. Preparation of Test Specimens10.1 Mixing Cement PastePrepare 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
35、 accordancewith the procedure described in Practice C305. Both a time ofsetting specimen and an autoclave bar may 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
36、 from theremainder of the batch.10.2 Molding SpecimensImmediately following prepara-tion of the time of setting specimen or completion of mixing,mold the test specimen in two approximately equal layers, eachlayer being compacted with the thumbs or forefingers byC151/C151M 182pressing the paste into
37、the corners, around the gauge studs, andalong the surface of the mold until a homogeneous specimen isobtained. Compact the top layer, cut off the paste flush with thetop of the mold with a thin-edged trowel, and smooth thesurface with a few strokes of the flat trowel. During theoperations of mixing
38、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 removedfrom the molds before 24 h, they shall be kept in the moistcloset or m
39、oist 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 temperature in a rack so that all sides of thespecimen will be exposed to s
40、aturated 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 autoclave should be occupied by the water.11.2 To permit air to escape from the
41、 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 rate that will bring the gauge pressure ofthe steam to 2 MPa 295 psi in 45 to
42、 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 0.07 MPa 10 psi at the end of 112 h. At theend of the 112-h period, slowl
43、y 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 the bars at a uniform rate by adding coldwater so that the temperature of
44、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 a length comparator reading.12. Calculation12.1 Calculate the change in le
45、ngth 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 length as the autoclave expansion. Indicate adecrease in length by a minus si
46、gn 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 oftwo properly conducted tests by the same operator for expan-sions of sim
47、ilar 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, results of two properly conducted tests from twodifferent laboratories f
48、or 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 autoclave; autoclave expansion; expansion; hydrauliccement; soundnessFor
49、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 identified the location of selected changes to this standard since the last issue(C151/C151M 16) that may impact the use of this standard. (Approved April 1, 2018.)(1) Removed previous footnotes 5 and 6.Committee C01 has identified the location of selected changes to this standard since th
