1、Designation: C 151 05Standard Test Method forAutoclave Expansion of Hydraulic Cement1This standard is issued under the fixed designation C 151; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、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 determination of the autoclaveexpansion of hydraulic cement by means of a test on a neatcement specimen.1.2 The values s
3、tated in inch-pound units are to be regardedas 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 and health practices and determine the applica-b
4、ility of regulatory limitations prior to use.For specific precau-tion statements, see the section on Safety Precautions.2. Referenced Documents2.1 ASTM Standards:2C 187 Test Method for Normal Consistency of HydraulicCementC 305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of
5、Plastic ConsistencyC 490 Practice for Use of Apparatus for the Determinationof Length 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 ConcretesC 856 Practice for P
6、etrographic Examination of HardenedConcreteC 1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsC 1157 Performance Specification for Hydraulic Cement3. Significance and Use3.1 The autoclave expansion test provides an
7、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 alkali-silica reaction that will not
8、 occur undernormal service conditions.4When excessive expansion of pastecontaining pozzolans occurs, it is recommended that thespecimens be examined (See Practice C 856) for evidence ofalkali-silica reaction (Note 1).NOTE 1If the excessive expansion has resulted from alkali-silicareaction under auto
9、clave conditions, the pozzolan can be evaluated foralkali reactivity using the procedure described in Performance Specifica-tion C 1157.5. Apparatus5.1 Weighing Devices and Weights, for determining themass of materials conforming to the requirements of Specifi-cation C 1005.5.2 Glass Graduates, 200
10、or 250-mLcapacity, and conform-ing to the requirements of Practice C 490.5.3 Molds, 1 by 1-in. (25.4 by 25.4-mm) cross section,conforming to the requirements of Practice C 490.5.4 Flat Trowel, having a straight-edged steel blade 4 to 6in. (100 to 150 mm) in length.5.5 Autoclave, consisting of a high
11、-pressure steam vesselprovided with a thermometer well. The autoclave shall beequipped with automatic controls and a rupture disk with abursting pressure of 350 psi (2.4 MPa) 6 5 %. In locationswhere the use of a rupture disk is not permitted, the autoclave1This test method is under the jurisdiction
12、 of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.31 on Volume Change.Current edition approved July 1, 2005. Published July 2005. Originally approvedin 1940. Last previous edition approved in 2000 as C 151 00.2For referenced ASTM standards, visit the ASTM website,
13、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 theHydration Expansion Characteristics of Port
14、land Cements,” Portland CementAssociation Research Department Bulletin 45, 1953, pp. 1-168.4Wang, H., “Autoclave Soundness Test Mischaracterizes Cement-Fly AshBlends by Introducing Alkali-Quartz Reaction,” Cement, Concrete, and Aggregates,Vol. 24, No. 2, 2002, pp. 68-72.1Copyright ASTM International
15、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.shall be equipped with a safety valve. In addition, the autoclaveshall be equipped with a vent valve to allow the escape of airduring the early part of the heating period and to release anysteam pressure remaining
16、at the end of the cooling period. Thepressure gage shall have a nominal capacity of 600 psi (4.1MPa), a dial with a nominal diameter of 412 in. (114 mm) andshall be graduated from 0 to 600 psi (0 to 5.1 MPa) with scaledivisions not exceeding 5 psi (0.03 MPa). The error in the gageshall not exceed 6
17、3 psi (6 0.02 MPa) at the operatingpressure of 295 psi (2 MPa). 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 gage pressure of 295 psi in 45 to 75 min from thetime the heat is turned o
18、n. The automatic control shall becapable of maintaining the gage pressure at 295 6 10 psi (2 60.07 MPa) for at least 3 h. A gage pressure of 295 6 10 psicorresponds to a temperature of 420 6 3 F (216 6 2 C). Theautoclave shall be designed to permit the gage pressure to dropfrom 295 psi to less than
19、10 psi in 112 h after the heat supplyhas been 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 68 to 420 F (20 to 216 C) and thatis electrochemically compatible with the pipe leading to it andto
20、 its holder.55.6 Length ComparatorThe comparator used for measur-ing length change of specimens shall conform to the require-ments of Practice C 490.6. Temperature and Humidity6.1 Molding RoomMaintain the temperature of the mold-ing room, dry materials and mixing water, and the relativehumidity of t
21、he molding room within the limits of PracticeC 490.6.2 Moist Storage FacilitiesMaintain the temperature andhumidity of the moist storage facilities to the requirements ofSpecification C511.7. Safety Precautions7.1 The pressure gage shall have a capacity of 600 psi (4.1MPa). A gage with too small or
22、too large a capacity may be ahazard, since for pressure above the specified maximumworking pressure, with a smaller capacity gage, the pressuremay be off scale, and with a larger capacity gage, the arc ofmovement may be too small to invite attention. The operatorshall be sure the gage hand has not p
23、assed the maximumgraduation on the scale.7.2 Test the pressure gage for proper operation. Always usea thermometer together with the pressure gage, so as to providea means of detecting any failure of the pressure gage to operateproperly, and to indicate any unusual condition.7.3 Maintain the automati
24、c 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 305 psi (2.1 MPa) specified inthis test method, that is, at about 330 psi (2.3 MPa). Unless themanufacturer has given specific instructions as to maintenanceof the sa
25、fety valve, test the valve twice each year.6Test with agage testing device, or by adjusting the automatic controls toallow the autoclave to reach a pressure of about 330 psi, atwhich pressure the safety valve will either open or be adjustedto open. Direct the safety valve discharge away from theoper
26、ator.NOTE 2Unexpected combinations of conditions may occur. Forexample, in one case the automatic control had failed, the safety valve hadbecome stuck, and the gage 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
27、 pin. This condition of the gage 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 top of the autoclave at the end ofthe test. Direct the vent
28、 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 autoclave well.7.6 The operator shall be made aware that f
29、or many auto-clave pressure gages the return of the gage hand to the initialrest or starting point does not necessarily indicate zero pressurewithin the autoclave; there may then still remain an appreciabledangerous pressure.8. Number of Test Specimens8.1 Make at least one test specimen.9. Preparati
30、on of Specimen Molds9.1 Prepare the specimen molds in accordance with therequirements of Practice C 490 except that molds need not besealed.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 c
31、onsistency in accordance with the proceduredescribed in Test Method C 187. Mix this batch in accordancewith the procedure described in Practice C 305. 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 al
32、ready 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 specimen or completion of mixing,mold the test specimen in two approximately equal layers, each
33、layer being compacted with the thumbs or forefingers bypressing the paste into the corners, around the gage 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 the
34、5A 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.C151052surface with a few strokes of the flat trowel. During theoperations of mixing and molding, protect the hand
35、s 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 moist room until time of test.
36、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 saturated steam. The autoclave
37、shall contain enough water, at an initial temperature of 68 to 82F (20 to 28 C), to maintain an atmosphere of saturated steamvapor during the entire test. Ordinarily 7 to 10 % of the volumeof the autoclave should be occupied by the water.11.2 To permit air to escape from the autoclave during theearl
38、y 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 gage pressure of thesteam to 295 psi (2 MPa) in 45 to 75 min from the time th
39、e heatis turned on. Maintain the 295 6 10 psi (2 6 0.07 MPa)pressure 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 10 psi at the end of 112 h. At the end of the112-h period, slowly release any remaining pressur
40、e by par-tially opening the vent valve until atmospheric pressure isattained. Then open the autoclave and place the test specimenin water at a temperature above 194 F (90 C). Cool the watersurrounding the bars at a uniform rate by adding cold water sothat the temperature of the water will be lowered
41、 to 74 F (23C) in 15 min. Maintain the water surrounding the specimensat 74 F for an additional 15 min; then, remove one specimenat 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 length of the test specime
42、n bysubtracting the length comparator reading before autoclavingfrom that after autoclaving, and report as percent of effectivegage length to the nearest 0.01 %. Report the percentage ofincrease in length as the autoclave expansion. Indicate adecrease in length by a minus sign prefixed to the percen
43、tvalue.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 similar batches should not d
44、iffer 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. There-fore, results of two properly conducted tests from two differentlaboratories for expansions of simila
45、r batches should not differfrom 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 additional useful infor
46、mation 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.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stan
47、dard. 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 revie
48、wed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsibl
49、e 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 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 websit
