1、Designation: C1012/C1012M 10Standard Test Method forLength Change of Hydraulic-Cement Mortars Exposed to aSulfate Solution1This standard is issued under the fixed designation C1012/C1012M; the number immediately following the designation indicates theyear of original adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of lengthchange of mortar bars immersed in a sulfate solu
3、tion. Mortarbars made using mortar described in Test Method C109/C109M are cured until they attain a compressive strength of20.0 6 1.0 MPa 3000 6 150 psi, as measured using cubesmade of the same mortar, before the bars are immersed.1.2 The values stated in either SI units or inch-pound unitsare to b
4、e regarded separately as standard. Within the text, theinch-pound units are shown in brackets. 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 stan
5、dard.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.2. Referen
6、ced Documents2.1 ASTM Standards:2C109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C114 Test Methods for Chemical Analysis of HydraulicCementC150 Specification for Portland CementC157/C157M Test Method for Length Change of HardenedHydrauli
7、c-Cement Mortar and ConcreteC215 Test Method for Fundamental Transverse, Longitudi-nal, and Torsional Resonant Frequencies of ConcreteSpecimensC305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC348 Test Method for Flexural Strength of Hydraulic-Cement Mo
8、rtarsC349 Test Method for Compressive Strength of Hydraulic-Cement Mortars (Using Portions of Prisms Broken inFlexure)C452 Test Method for Potential Expansion of Portland-Cement Mortars Exposed to SulfateC490 Practice for Use of Apparatus for the Determinationof Length Change of Hardened Cement Past
9、e, Mortar, andConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC595 Specification for Blended Hydraulic CementsC597 Test Method for Pulse Velocity Through ConcreteC618 Specification for Coal Fly Ash
10、and Raw or CalcinedNatural Pozzolan for Use in ConcreteC684 Test Method for Making, Accelerated Curing, andTesting Concrete Compression Test SpecimensC778 Specification for SandC917 Test Method for Evaluation of Cement StrengthUniformity From a Single SourceC989 Specification for Slag Cement for Use
11、 in Concreteand MortarsD1193 Specification for Reagent WaterE18 Test Methods for Rockwell Hardness of Metallic Ma-terials2.2 American Concrete Institute Reports:ACI C201-2R-01 Guide to Durable Concrete33. Significance and Use3.1 This test method provides a means of assessing thesulfate resistance of
12、 mortars made using portland cement,blends of portland cement with pozzolans or slags, and blendedhydraulic cements. Method C452 is suitable for evaluatingportland cements but not blended cements or blends of portlandcement with pozzolans or slags.3.2 The standard exposure solution used in this test
13、 method,unless otherwise directed, contains 352 moles of Na2SO4per1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.29 on Sulfate Resistance.Current edition approved Dec. 15, 2010. Published January 2011. Originallyapprove
14、d in 1984. Last previous edition approved in 2009 as C1012/C1012M09.DOI: 10.1520/C1012_C1012M-10.2For 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 Docum
15、ent Summary page onthe ASTM website.3Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.concrete.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
16、ohocken, PA 19428-2959, United States.m3(50 g/L). Other sulfate concentrations or other sulfates suchas MgSO4may be used to simulate the environmental exposureof interest. Further discussion of these and other technicalissues is given in the Appendix.4. Apparatus4.1 Mixer, conforming to the requirem
17、ents of PracticeC305.4.2 Cube Molds, conforming to the requirements of TestMethod C109/C109M.4.3 Bar Molds, conforming to the requirements of Specifi-cation C490.4.4 Comparator, conforming to the requirements of Speci-fication C490.4.5 ContainersThe containers in which the bars are im-mersed shall b
18、e corrosion resistent such as plastic, glass, orceramic. Support the bars so that no end or side of a bar restsagainst the container. Seal the container with a lid so that thesulfate solution cannot evaporate.4.6 Curing Tank, conforming to the requirements of TestMethod C684.5. Reagents and Material
19、s5.1 Purity of ReagentsUSP or technical grade chemicalsmay be used, provided it is established that any reagent used isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination. When tests are made that areexpected to produce results that are close to an accept
20、ance-rejection value, it is recommended that reagent grade chemi-cals be used. Such chemicals shall conform to the specifica-tions of the Committee on Analytical Reagents for theAmerican Chemical Society where such specifications areavailable.45.2 Purity of WaterUnless otherwise indicated, reference
21、sto water shall be understood to mean reagent water conformingto Type IV of Specification D1193.5.3 Sodium Sulfate (Na2SO4)Check the water content byloss on ignition each time the solution is prepared. Anyanhydrous or hydrated sodium sulfate may be used if the watercontent of the salt is checked by
22、loss on ignition and propercorrections made to account for the specified sulfate concen-tration.5.4 Sulfate SolutionEach litre of solution shall contain50.0gofNa2SO4dissolved in 900 mL of water, and shall bediluted with additional distilled or deionized water to obtain1.0 L of solution. Mix the solu
23、tion on the day before use, cover,and store at 23.0 6 2.0 C 73.5 6 3.5 F. Determine the pHof the solution before use; reject the solution if the pH range isoutside 6.0 to 8.0. Maintain the volume proportion of sulfatesolution to mortar bars in a storage container at 4.0 6 0.5volumes of solution to 1
24、 volume of mortar bars. For mortarbars1by1by1114 in. (volume of 184 mL 11.25 in.3), this is645 to 830 mL of solution per mortar bar in the storagecontainer. For mortar bars 25 by 25 by 285 mm (volume 178mL), this is 625 to 800 mL of solution per mortar bar in thestorage container.5.5 Materials:5.5.1
25、 Graded Standard Sand, as specified in SpecificationC778.5.5.2 Stainless Steel Gauge Studs, as specified in Specifica-tion C490.6. Hazards6.1 WarningFresh hydraulic cementitious mixtures arecaustic and may cause chemical burns to skin and tissue uponprolonged exposure.57. Preparing Mortars7.1 Make m
26、ortars as described in Test Method C109/C109M, that is, 1 part cement to 2.75 parts of sand by mass.Use a water-cement ratio by mass of 0.485 for all non-air-entraining portland cements and 0.460 for all air-entrainingportland cements. Use a water-cement ratio by mass of 0.485for non-air-entraining
27、portland-pozzolan (IP) and portland-blast furnace slag (IS) cements. For blends of portland cementwith a pozzolan or slag, use a water-cement ratio that developsa flow within 65 of that of the portland-cement mortar at awater-cement ratio of 0.485.8. Specimen Molds8.1 Prepare the specimen molds in a
28、ccordance with therequirements of Specification C490 except the interior surfacesof the mold shall be covered with a release agent. A releaseagent will be acceptable if it serves as a parting agent withoutaffecting the setting of the cement and without leaving anyresidue that will inhibit the penetr
29、ation of water into thespecimen.NOTE 1TFE-fluorocarbon tape complies with the requirements for amold release agent.9. Procedure9.1 Molding and Initial Curing of SpecimensMold the testbars in accordance with Test Method C157/C157M. Mold thecubes in accordance with Test Method C109/C109M. A set ofspec
30、imens to test one cement consists of 6 bars and up to 21cubes (Note 2). Immediately after molding, cover the moldswith a rigid steel, glass, or plastic plate, seal the plate to themold so as to be watertight, and place the mold in the curingtank in water at 35 6 3C956 5 F for 2312 h 6 30 min,as in T
31、est Method C684, Procedure A (Warm-Water Method).Place the sealed molds in the curing tank with the bottom of thebars as cast down, that is, in the same relative position in whichthe bars were cast. At 2312 h 6 30 min, remove molds fromtank and demold the specimens.NOTE 2The set of cubes consists of
32、 21 cubes to be tested as describedherein when significant information on the strength development rate isnot available. When information is available (as for example, from the use4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For Suggestions
33、 on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.5See Manual of Cement Testing, Secti
34、on on Safety, Annual Book of ASTMStandards, Vol 04.01.C1012/C1012M 102of the procedures of Test Method C917) that would justify making fewercubes, only those needed to confirm the time the mortar achieves 20.0 61.0 MPa 3000 6 150 psi are needed.9.2 Subsequent Curing and Preparation for TestAfterdemo
35、lding, store all bars and cubes, except the two to bebroken, in a curing tank of saturated limewater at 23.0 6 2.0C 73.5 6 3.5 F. Break two cubes in compression inaccordance with Test Method C109/C109M after demoldingwhen the specimens have cooled to ambient temperature undermoist cloths. If the mea
36、n strength of the two cubes is 20 MPa2850 psi or more, observe and record comparator readings inaccordance with Specification C490 and as prescribed in thesection on Measurements of Length Change and place all thebars in the sulfate solution. If 20 MPa 2850 psi is notachieved, store the demolded cub
37、es and mortar bars in thecuring tank and test additional cubes. Predict from the first twocubes when a compressive strength of at least 20 MPa 2850psi will be reached. Verify the prediction, and at that timeobserve and record comparator readings and place all the barsin the sulfate solution (Note 3)
38、. This measurement is desig-nated as the initial length. The storage temperature and testtemperature shall be 23.0 6 2.0 C 73.5 6 3.5F.NOTE 3If the value for strength at 24 h is less than 20.0 MPa 2850psi and additional testing on the same day is not possible, or, is unlikelyto yield a value over 20
39、.0 MPa 2850 psi and the strength is over 21 MPa3150 psi when tested early the next day, it is not necessary to remake thebatch.9.3 Storage of Test Bars during Exposure to Test SolutionCover the container of the bars and test solution, and seal it toprevent evaporation from the inside, or dilution wi
40、th waterfrom the outside. (See Note 4.) The storage temperature andtest temperature shall be 23.0 6 2.0 C 73.5 6 3.5 F. (SeeNote 5.)NOTE 4Gaffers tape or duct tape has been found to be suitable forsealing the container.NOTE 5This is the same temperature and temperature range as thatspecified for moi
41、st rooms in Specification C511.9.4 Measurements of Length ChangeAt1,2,3,4,8,13,and 15 weeks after the bars are placed in the sulfate solution,test them for length change using the length comparator inaccordance with Specification C490. Review the data at 15weeks. Make the subsequent measurements at
42、4, 6, 9, and 12months. If at any time the rate of change between readings isgreat, insert other readings as needed to ensure the intervals areshort enough to permit observing and reporting the behavior ofthe bars. If compliance withACI C201-2R-01 Class 3 exposureis required, measure the bars at 4, 6
43、, 9, 12, 15, and 18 months(Note 6).NOTE 6ACI C201-2R-01 requires an 18-month limit for Class 3exposure.9.4.1 Details of Measurement of Bars for Length Change:9.4.1.1 Clean the hole in the base of the comparator intowhich the gauge stud on the lower end of the bar fits (this holetends to collect wate
44、r and sand and should be cleaned afterevery reading). Read and record the comparator indication ofthe length of the reference bar. Take one bar out of immersion,blot the pins, put the bar in the comparator, read, and record theindication. Return the bar to immersion and clean the hole inthe base of
45、the comparator. Take out the second bar and treat itin a like manner. Return the second bar to immersion, recordthe reading, and clean the hole in the base of the comparator.Continue the procedure until all bars have been read, returnedto immersion, and the readings recorded, cleaning the hole inthe
46、 bottom of the comparator each time. After reading the lastbar, clean the hole in the comparator base and read and recordthe reference-bar indication.9.4.1.2 When the required strength of the mortar is achievedin accordance with 9.2, store the bars in fresh sulfate solution.At subsequent readings fo
47、r length change, proceed as describedin 9.4.1.1; cleaning the socket in the base of the comparatorbefore reading the reference bar initially and after reading eachmortar bar. Record reference bar and mortar bar readings. Readand record the reference bar again after measurement of the lastbar. Blot o
48、nly around the pins (Note 7). Return each bar to theused sulfate solution after reading. Discard and change theused solution after reading of the bars only at standardintervals: 1, 2, 3, 4, 8, 13, 15 weeks and 4, 6, 9, 12, 15, and 18months. Rinse the container once with water, pouring out waterand d
49、ebris. Replace the frame holding the bars in the container,fill the container with enough new sulfate solution to immersebars, and secure the lid on the container.NOTE 7The purpose of the minimal blotting of the pins and noblotting of the bars is to avoid drying and shrinkage of the bars. It has beenobserved that if the pins are blotted, and the bar placed in the comparatorand the dial read, and the bar is then wiped gently with a dry cloth, the barwill shrink measurably. Therefore, drying should be minimized.9.4.2 Examinat
