ASTM C1202-2017a Standard Test Method for Electrical Indication of Concrete&apos s Ability to Resist Chloride Ion Penetration《混凝土抗氯离子渗透能力的电指示的标准试验方法》.pdf

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1、Designation: C1202 17aStandard Test Method forElectrical Indication of Concretes Ability to Resist ChlorideIon Penetration1This standard is issued under the fixed designation C1202; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t

2、he year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the elec-trical conductance of concrete to provide a rapid in

3、dication ofits resistance to the penetration of chloride ions. This testmethod is applicable to types of concrete where correlationshave been established between this test procedure and long-term chloride ponding procedures such as those described inAASHTO T 259. Examples of such correlations are di

4、scussedin Refs 1-5.21.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figu

5、res) shall not be consideredas requirements of the standard.1.4 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

6、ility of regulatory limitations prior to use.1.5 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, Guides and Recom-mendations issued by the

7、World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC192/C192M Practice for Mak

8、ing and Curing Concrete TestSpecimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC802 Practice for Conducting an Interlaboratory Test Pro-gram to Determine the Precision of Test Methods forConstruction Materials2.2 AASHTO Stan

9、dard:T 259 Method of Test for Resistance of Concrete to Chlo-ride Ion Penetration43. Summary of Test Method3.1 This test method consists of monitoring the amount ofelectrical current passed through 50-mm thick slices of100-mm nominal diameter cores or cylinders during a 6-hperiod. A potential differ

10、ence of 60 V dc is maintained acrossthe ends of the specimen, one of which is immersed in asodium chloride solution, the other in a sodium hydroxidesolution. The total charge passed, in coulombs, has been foundto be related to the resistance of the specimen to chloride ionpenetration.4. Significance

11、 and Use4.1 This test method covers the laboratory evaluation of theelectrical conductance of concrete samples to provide a rapidindication of their resistance to chloride ion penetration. Inmost cases the electrical conductance results have shown goodcorrelation with chloride ponding tests, such as

12、 AASHTOT259, on companion slabs cast from the same concretemixtures (Refs 1-5).4.2 This test method is suitable for evaluation of materialsand material proportions for design purposes and research anddevelopment.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concret

13、e Aggregates and is the direct responsibility of SubcommitteeC09.66 on Concretes Resistance to Fluid Penetration.Current edition approved Dec. 1, 2017. Published December 2017. Originallyapproved in 1991. Last previous edition approved in 2017 as C1202 17. DOI:10.1520/C1202-17A.2The boldface numbers

14、 in parentheses refer to the list of references at the end ofthis standard.3For 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

15、 ASTM website.4Methods of Sampling and Testing, 1986, American Association of StateHighway and Transportation Officials, 444 N. Capitol St., NW, Washington, DC20001.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West

16、 Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Tra

17、de Organization Technical Barriers to Trade (TBT) Committee.14.3 Sample age has significant effects on the test results,depending on the type of concrete and the curing procedure.Most concretes, if properly cured, become progressively andsignificantly less permeable with time.4.4 This test method wa

18、s developed originally for evalua-tions of alternative materials, but in practice its use has evolvedto applications such as quality control and acceptance testing.Factors such as ingredient materials used in concrete mixturesand the method and duration of curing test specimens affect theresults of

19、this test (See Note 1). When this method is used formixture qualification and acceptance testing, it is imperativethat the curing procedures and the age at time of testing beclearly specified.NOTE 1When using this test for determining acceptability of concretemixtures, statistically-based criteria a

20、nd test age for prequalification, or foracceptance based on jobsite samples, should be stated in project specifi-cations. Acceptance criteria for this test should consider the sources ofvariability affecting the results and ensure balanced risk between supplierand purchaser. The anticipated exposure

21、 conditions and time before astructure will be put into service should be considered. One approach toestablishing criteria is discussed in Ref 6.4.5 Table X1.1 in Appendix X1 provides a qualitativerelationship between the results of this test and the chloride ionpenetrability of concrete.4.6 Care sh

22、ould be taken in interpreting results of this testwhen it is used on surface-treated concretes, for example,concretes treated with penetrating sealers. The results from thistest on some such concretes indicate low resistance to chlorideion penetration, while 90-day chloride ponding tests on com-pani

23、on slabs show a higher resistance.4.7 The details of the test method apply to 100-mm nominaldiameter specimens. This includes specimens with actualdiameters ranging from 95 to 100 mm. Other specimendiameters may be tested with appropriate changes in theapplied voltage cell design (see 7.5 and Fig. 1

24、).4.7.1 For specimen diameters other than 95 mm, the testresult value for total charge passed must be adjusted followingthe procedure in 11.2. For specimens with diameters less than95 mm, particular care must be taken in coating and mountingthe specimens to ensure that the conductive solutions are a

25、bleto contact the entire end areas during the test.5. Interferences5.1 This test method can produce misleading results whencalcium nitrite has been admixed into a concrete. The resultsfrom this test on some such concretes indicate higher coulombvalues, that is, lower resistance to chloride ion penet

26、ration,than from tests on identical concrete mixtures (controls)without calcium nitrite. However, long-term chloride pondingtests indicate the concretes with calcium nitrite were at least asresistant to chloride ion penetration as the control mixtures.NOTE 2Other admixtures might affect results of t

27、his test similarly.Long term ponding tests are recommended if an admixture effect issuspected.5.2 Since the test results are a function of the electricalresistance of the specimen, the presence of reinforcing steel orother embedded electrically conductive materials may have asignificant effect. The

28、test is not valid for specimens containingreinforcing steel positioned longitudinally, that is, providing acontinuous electrical path between the two ends of the speci-men.6. Apparatus6.1 Vacuum Saturation Apparatus (see Fig. 2 for example):6.1.1 Separatory Funnel, or other sealable, bottom-draining

29、container with a minimum capacity of 500 mL.6.1.2 Beaker (1000 mL or larger) or other containerCapable of holding concrete specimen(s) and water and offitting into vacuum desiccator (see 6.1.3).6.1.3 Vacuum DesiccatorThe volume of desiccator shallbe large enough to maintain sample immersion througho

30、ut thesaturation process. Desiccator must allow two hose connec-tions through a rubber stopper and sleeve or through a rubberstopper only. Each connection must be equipped with astopcock.6.1.4 Vacuum Pump orAspiratorCapable of maintaining apressure of less than 50 mm Hg (6650 Pa) in desiccator.NOTE

31、3Since vacuum will be drawn over water, a vacuum pumpshould be protected with a water trap, or pump oil should be changed aftereach operation.6.1.5 Vacuum Gage or ManometerAccurate to 65mmHg (6665 Pa) over range 0100 mm Hg (013300 Pa)pressure.6.2 Coating Apparatus and Materials:6.2.1 CoatingRapid se

32、tting, electrically nonconductive,capable of sealing side surface of concrete cores.6.2.2 Balance or Scale, Paper Cups, Wooden Spatulas, andDisposable BrushesFor mixing and applying coating.6.3 Specimen Sizing Equipment (not required if samples arecast to final specimen size).6.3.1 Movable Bed Water

33、-Cooled Diamond Saw or SiliconCarbide Saw.7. Reagents, Materials, and Test Cell7.1 Specimen-Cell SealantCapable of sealing concrete topoly (methyl methacrylate), for example, Plexiglas, againstwater and dilute sodium hydroxide and sodium chloridesolutions at temperatures up to 90 C; examples include

34、 RTVsilicone rubbers, silicone rubber caulkings, other syntheticrubber sealants, silicone greases, and rubber gaskets.7.2 Sodium Chloride Solution3.0 % by mass (reagentgrade) in distilled water.7.3 Sodium Hydroxide Solution0.3 N (reagent grade) indistilled water.7.3.1 Bring the NaOH solution to room

35、 temperature prior touse (Note 4).NOTE 4Mixing 0.3 N NaOH solution generates heat, affecting theconductivity of the solution and the results of the test.7.3.2 WarningBefore using NaOH, review: (1) the safetyprecautions for using NaOH; (2) first aid for burns; and (3) theemergency response to spills,

36、 as described in the manufactur-ers Material Safety Data Sheet or other reliable safety litera-ture. NaOH can cause very severe burns and injury to unpro-tected skin and eyes. Suitable personal protective equipmentC1202 17a2should always be used. These should include full-face shields,rubber aprons,

37、 and gloves impervious to NaOH. Gloves shouldbe checked periodically for pin holes.7.4 Filter PapersNo. 2, 90-mm diameter (not required ifrubber gasket is used for sealant (see 7.1) or if sealant can beapplied without overflowing from shim onto mesh).7.5 Applied Voltage Cell (see Fig. 1 and Fig. 3)T

38、wosymmetric poly (methyl methacrylate) chambers, each contain-ing electrically conductive mesh and external connectors. Onedesign in common use is shown in Fig. 1 and Fig. 3. However,other designs are acceptable, provided that overall dimensions(including dimensions of the fluid reservoir) are the s

39、ame asshown in Fig. 1 and width of the screen and shims are asshown.7.6 Temperature Measuring Device (optional)0 to 120Crange.7.7 Voltage Application and Data Readout ApparatusCapable of holding 60 6 0.1 V dc across applied voltage cellover entire range of currents and of displaying voltage accurate

40、to 60.1 V and current to 61 mA. Apparatus listed in 7.7.1 7.7.5 is a possible system meeting this requirement.FIG. 1 Applied Voltage Cell (Construction Drawing)C1202 17a37.7.1 VoltmeterDigital (DVM), 3 digit, minimum 099.9V range, rated accuracy 60.1 %.7.7.2 VoltmeterDigital (DVM), 412 digit, 0200 m

41、Vrange, rated accuracy 60.1 %.7.7.3 Shunt Resistor100 mV, 10A rating, tolerance6 0.1 %. Alternatively, a 0.01 resistor, tolerance 6 0.1 %,may be used, but care must be taken to establish very lowresistance connections.7.7.4 Constant Voltage Power Supply 080 V dc, 02 A,capable of holding voltage cons

42、tant at 60 6 0.1 V over entirerange of currents.7.7.5 CableTwo conductor, AWG No. 14 (1.6 mm),insulated, 600 V.8. Test Specimens8.1 Sample preparation and selection depends on the pur-pose of the test. For evaluation of materials or theirproportions, samples may be (a) cores from test slabs or froml

43、arge diameter cylinders or (b) 100-mm diameter cast cylin-ders. For evaluation of structures, samples shall be cores fromthe structure. Coring shall be done with a drilling rig equippedwith a 100-mm diameter diamond-dressed core bit. Select andcore samples following procedures in Test Method C42/C42

44、M.Cylinders cast in the laboratory shall be prepared followingprocedures in Practice C192/C192M.NOTE 5The maximum allowable aggregate size has not been estab-lished for this test. Users have indicated that test repeatability issatisfactory on specimens from the same concrete batch for aggregates upt

45、o 25.0 mm nominal maximum size.8.2 When results of this test method are used for evaluationof materials or mixture proportions based on cast specimens forpurposes of quality control, mixture submittals, or acceptanceof concrete, prepare at least two 100-mm diameter cylindricalspecimens in accordance

46、 with Practice C192/C192M for con-crete mixtures prepared in the laboratory or Practice C31/C31M from samples of fresh concrete obtained in the field.Moist cure specimens in accordance with 8.2.1 for concretemixtures containing only portland cement. For concrete mix-tures containing supplementary ce

47、mentitious materials useextended moist curing in accordance with 8.2.2 (see Note 6)unless the accelerated moist curing method of 8.2.3 is specified(see Note 7). Alternatives to these curing methods and dura-tions are permitted when specified. Use the same method andduration of curing for preparing m

48、ixture submittals, for subse-quent acceptance testing, and for comparing two or moremixtures.8.2.1 Moist CuringCure test specimens for 28 days inaccordance with Practice C192/C192M or in accordance withthe standard curing procedure of Practice C31/C31M forspecimens prepared in the field.8.2.2 Extend

49、ed Moist CuringCure test specimens for 56days in accordance with Practice C192/C192M for specimensprepared in the laboratory or in accordance with the standardcuring procedure of Practice C31/C31M for specimens pre-pared in the field.8.2.3 Accelerated Moist CuringProvide 7 days of moistcuring in accordance with Practice C192/C192M for specimensprepared in the laboratory or in accordance with the standardcuring procedure of Practice C31/C31M for specimens pre-pared in the field. After 7 days of moist curing, immerse thespecimens for 21 days