1、Designation: C151/C151M 15C151/C151M 16Standard 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
2、 revision. A 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 autoclave expansion of hydraulic cement by means of a test on a neat cements
3、pecimen. a hardened cement paste when exposed to the autoclave conditions in this method.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independ
4、ently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and
5、 health practices and determine the applicability of regulatorylimitations prior to use. For specific precaution statements, see the section on Safety Precautions.2. Referenced Documents2.1 ASTM Standards:2C187 Test Method for Amount of Water Required for Normal Consistency of Hydraulic Cement Paste
6、C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic ConsistencyC490 Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and ConcreteC511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage
7、 Tanks Used in the Testing of HydraulicCements and ConcretesC856 Practice for Petrographic Examination of Hardened ConcreteC1005 Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing ofHydraulic CementsC1157 Performance Specification for Hydra
8、ulic Cement3. Significance and Use3.1 The autoclave expansion test provides an index of potential delayed expansion caused by the hydration of CaO or MgO,or both, when present in hydraulic cement.34. Interferences4.1 Pozzolans containing fine-grained quartz have been reported to cause excessive expa
9、nsion under autoclave test conditionsdue to alkali-silica reaction that will not occur under normal service conditions.4 When excessive expansion of paste containingpozzolans occurs, it is recommended that the specimens be examined (see Practice C856) for evidence of alkali-silica reaction(Note 1).N
10、OTE 1If the excessive expansion has resulted from alkali-silica reaction under autoclave conditions, the pozzolan can be evaluated for alkalireactivity using the procedure described in Performance Specification C1157.5. Apparatus5.1 Weighing Devices and Weights, for determining the mass of materials
11、 conforming to the requirements of SpecificationC1005.1 This test method is under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.31 on Volume Change.Current edition approved Jan. 1, 2015Dec. 15, 2016. Published January 2015December 2016. Origina
12、lly approved in 1940. Last previous edition approved in 20092015as C151/C151M 09.C151/C151M 15. DOI: 10.1520/C0151_C0151M-15.10.1520/C0151_C0151M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standa
13、rdsvolume information, refer to the standards Document Summary page on the ASTM website.3 Gonnerman, H. F., Lerch, W. and Whiteside, T. M., “Investigations of the Hydration Expansion Characteristics of Portland Cements,” Portland Cement AssociationResearch Department Bulletin 45, pp. 1168, 1953.4 Wa
14、ng, H., “Autoclave Soundness Test Mischaracterizes Cement-FlyAsh Blends by IntroducingAlkali-Quartz Reaction,” Cement, Concrete, and Aggregates, Vol 24, No.2, pp. 6872, 2002.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what chang
15、es have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the offici
16、al document.*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 States15.2 Glass Graduates, 200 or 250-mL capacity, and conforming to the requirements of Practice C490.5.3 Molds, c
17、onforming to the requirements of Practice C490 for test specimens used in the determination of length change ofcement paste.5.4 Flat Trowel, conforming to the requirements of Test Method C187.5.5 Autoclave, consisting of a high-pressure steam vessel provided with a thermometer well. The autoclave sh
18、all be equippedwith automatic controls and either a rupture disk with a bursting pressure of 2.4 MPa 350 psi65 % or a safety valve that actuatesat this pressure. In addition, the autoclave shall be equipped with a vent valve to allow the escape of air during the early part ofthe heating period and t
19、o release any steam pressure remaining at the end of the cooling period. The pressure gauge shall have anominal capacity of 4.0 MPa 600 psi, a dial with a nominal diameter of 115 mm 412 in. and shall be graduated from 0 to 4.0MPa 0 to 600 psi with scale divisions not exceeding 0.03 MPa 5 psi. The er
20、ror in the gauge shall not exceed 6 0.02 MPa 63 psi at the operating pressure of 2 MPa 295 psi. The capacity of the heating unit shall be such that with maximum load (waterplus specimens) the pressure of the saturated steam in the autoclave may be raised to a gauge pressure of 2 MPa 295 psi in 45to
21、75 min from the time the heat is turned on. The automatic control shall be capable of maintaining the gauge pressure at 2 60.07 MPa 295 6 10 psi for at least 3 h. A gauge pressure of 2 6 0.07 MPa 295 6 10 psi corresponds to a temperature of 2166 2C 420 6 3F. The autoclave shall be designed to permit
22、 the 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 has been shut off.5.5.1 Rupture DiskThe rupture disk shall be made of a material having a tensile strength that is relatively insensitive totemperature in the range 20 to 216C 68 to
23、 420F and that is electrochemically compatible with the pipe leading to it and to itsholder.55.6 Length ComparatorThe comparator used for measuring length change of specimens shall conform to the requirements ofPractice C490.6. Temperature and Humidity6.1 Molding RoomMaintain the temperature of the
24、molding room, dry materials and mixing water, and the relative humidityof the molding room within the limits of Practice C490.6.2 Moist Storage FacilitiesMaintain the temperature and humidity of the moist storage facilities to the requirements ofSpecification C511.7. Safety Precautions7.1 The pressu
25、re gauge shall have a capacity of 4.0 MPa 600 psi. A gauge with too small or too large a capacity may be ahazard, since for pressure above the specified maximum working pressure, with a smaller capacity gauge, the pressure may be offscale, and with a larger capacity gauge, the arc of movement may be
26、 too small to invite attention. The operator shall be sure thegauge hand has not passed the maximum graduation on the scale.7.2 Test the pressure gauge for proper operation. Always use a thermometer together with the pressure gauge, so as to providea means of detecting any failure of the pressure ga
27、uge to operate properly, and to indicate any unusual condition.7.3 Maintain the automatic control in proper working order at all times.7.4 Set the safety valve to relieve the pressure at about 6 to 10 % above the maximum of 2.1 MPa 305 psi specified in thistest method, that is, at about 2.3 MPa 330
28、psi. Unless the manufacturer has given specific instructions as to maintenance of thesafety valve, test the valve twice each year.6 Test with a gauge testing device, or by adjusting the automatic controls to allow theautoclave to reach a pressure of about 2.3 MPa 330 psi, at which pressure the safet
29、y valve will either open or be adjusted to open.Direct the safety valve discharge away from the operator.NOTE 2Unexpected combinations of conditions may occur. For example, in one case the automatic control had failed, the safety valve had becomestuck, and the gauge hand, which at first glance appea
30、red to be at about zero, had passed the maximum graduation and had come to stop on the wrongside of the pin. This condition of the gauge was finally detected and the pressure, then of an unknown magnitude, was released before failure could occurin the apparatus.7.5 Wear heavy leather work gloves to
31、prevent burning of the hands when removing the top of the autoclave at the end of thetest. Direct the vent valve away from the operator. When removing the autoclave lid, tilt it so that any steam escaping from beneaththe lid will be discharged away from the operator. Care shall be taken to avoid sca
32、lding by any liquid that may have been usedin the autoclave well.7.6 The operator shall be made aware that for many autoclave pressure gauges the return of the gauge hand to the initial restor starting point does not necessarily indicate zero pressure within the autoclave; there may then still remai
33、n an appreciabledangerous pressure. Procedures in 11.2 shall be followed.5 A list of suppliers of autoclave rupture disks and gaskets is maintained at ASTM Headquarters.6 A list of facilities for testing autoclave safety valves is maintained at ASTM Headquarters.C151/C151M 1628. Number of Test Speci
34、mens8.1 Make at least one test specimen.9. Preparation of Specimen Molds9.1 Prepare the specimen molds in accordance with the requirements of Practice C490 except that molds need not be sealed.10. Preparation of Test Specimens10.1 Mixing Cement PastePrepare the standard batch consisting of 650 g of
35、cement and sufficient water to give a paste ofnormal consistency in accordance with the procedure described in Test Method C187. Mix this batch in accordance with theprocedure described in Practice C305. Both a time of setting specimen and an autoclave bar may be made from the same batch.If the past
36、e to be used for time of setting is the paste sample already used to determine normal consistency, then the autoclave barmay be prepared immediately from the remainder of the batch.10.2 Molding SpecimensImmediately following preparation of the time of setting specimen or completion of mixing, moldth
37、e test specimen in two approximately equal layers, each layer being compacted with the thumbs or forefingers by pressing thepaste into the corners, around the gauge studs, and along the surface of the mold until a homogeneous specimen is obtained.Compact the top layer, cut off the paste flush with t
38、he top of the mold with a thin-edged trowel, and smooth the surface with afew strokes of the flat trowel. During the operations of mixing and molding, protect the hands with rubber gloves.10.3 Storage of Test SpecimensAfter filling the mold, place it in the moist closet or moist room. Store the spec
39、imens in themolds in the moist enclosure for at least 20 h; if removed from the molds before 24 h, they shall be kept in the moist closet ormoist room until time of test.11. Procedure11.1 At 24 h 6 30 min after molding, remove the specimens from the moist atmosphere, immediately obtain a lengthcompa
40、rator reading for each specimen, and place in the autoclave at room temperature in a rack so that all sides of the specimenwill be exposed to saturated steam. The autoclave shall contain enough water, at an initial temperature of 20 to 28C 68 to 82F,to maintain an atmosphere of saturated steam vapor
41、 during the entire test. Ordinarily 7 to 10 % of the volume of the autoclaveshould be occupied by the water.11.2 To permit air to escape from the autoclave during the early portion of the heating period, leave the vent valve open untilsteam begins to escape. (WarningSee the section on Safety Precaut
42、ions). Close the valve and raise the temperature of theautoclave at a rate that will bring the gauge pressure of the steam to 2 MPa 295 psi in 45 to 75 min from the time the heat isturned on. Maintain the 2 6 0.07 MPa 295 6 10 psi pressure for 3 h. At the end of the 3-h period, shut off the heat sup
43、ply andcool the autoclave at such a rate that the pressure will be less than 0.07 MPa 10 psi at the end of 112 h. At the end of the 112-hperiod, slowly release any remaining pressure by partially opening the vent valve until atmospheric pressure is attained. Then openthe autoclave and place the test
44、 specimen in water at a temperature above 90C 194F. Cool the water surrounding the bars ata uniform rate by adding cold water so that the temperature of the water will be lowered to 23C 74F in 15 min. Maintain thewater surrounding the specimens at 23C 74F for an additional 15 min; then, remove one s
45、pecimen 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 length of the test specimen by subtracting the length comparator reading before autoclaving fromthat after autoclaving, and report as percent of ef
46、fective gauge length to the nearest 0.01 %. Report the percentage of increase inlength as the autoclave expansion. Indicate a decrease in length by a minus sign prefixed to the percent value.13. Precision and Bias13.1 PrecisionThe single-operator (within-laboratory) standard deviation has been found
47、 to be 0.024 % throughout the rangeof 0.11 % to 0.94 % expansions. Therefore, results of two properly conducted tests by the same operator for expansions of similarbatches should not differ from each other by more than 0.07 % expansion. The multi-laboratory (between laboratory) standarddeviation has
48、 been found to be 0.030 % throughout the range of 0.11 % to 0.94 % expansions. Therefore, results of two properlyconducted tests from two different laboratories for expansions of similar batches should not differ from each other by more than0.09 % expansion.13.2 BiasSince there is no accepted refere
49、nce material suitable for determining bias, bias has not been determined.14. Keywords14.1 autoclave; autoclave expansion; expansion; hydraulic cement; soundnessC151/C151M 163For 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 15) that may
