ASTM C1202-2012 Standard Test Method for Electrical Indication of Concretes Ability to Resist Chloride Ion Penetration《混凝土耐氯离子穿透能力电标的标准试验方法》.pdf

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1、Designation: C1202 12Standard 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, th

2、e 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 ind

3、ication 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 dis

4、cussedin 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 figur

5、es) 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-bi

6、lity of regulatory limitations prior to use.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 Making and Curing ConcreteT

7、est Specimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials2.2 AASHTO Standard: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

8、 amount ofelectrical current passed through 50-mm thick slices of100-mm nominal diameter cores or cylinders during a 6-hperiod. A potential difference 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 hydroxidesoluti

9、on. The total charge passed, in coulombs, has been foundto be related to the resistance of the specimen to chloride ionpenetration.4. Significance and Use4.1 This test method covers the laboratory evaluation of theelectrical conductance of concrete samples to provide a rapidindication of their resis

10、tance to chloride ion penetration. Inmost cases the electrical conductance results have shown goodcorrelation with chloride ponding tests, such as AASHTOT 259, on companion slabs cast from the same concretemixtures (Refs 1-5).4.2 This test method is suitable for evaluation of materialsand material p

11、roportions for design purposes and research anddevelopment.4.3 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 was

12、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 th

13、is 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.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is th

14、e direct responsibility of SubcommitteeC09.66 on Concretes Resistance to Fluid Penetration.Current edition approved Feb. 1, 2012. Published March 2012. Originallyapproved in 1991. Last previous edition approved in 2010 as C120210. DOI:10.1520/C1202-12.2The boldface numbers in parentheses refer to th

15、e 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 ASTM website.4Methods of S

16、ampling and Testing, 1986, American Association of StateHighway and Transportation Officials, 444 N. Capitol St., NW, Washington, DC20001.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2

17、959, United States.NOTE 1When using this test for determining acceptability of concretemixtures, statistically-based criteria and test age for prequalification, or foracceptance based on jobsite samples, should be stated in project specifi-cations. Acceptance criteria for this test should consider t

18、he sources ofvariability affecting the results and ensure balanced risk between supplierand purchaser. The anticipated exposure 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 X

19、1 provides a qualitativerelationship between the results of this test and the chloride ionpenetrability of concrete.4.6 Care should 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 this

20、test on some such concretes indicate low resistance to chlorideion penetration, while 90-day chloride ponding tests on com-panion 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

21、to 100 mm. Other specimendiameters may be tested with appropriate changes in theapplied voltage cell design (see 7.5 and Fig. 1).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 l

22、ess than95 mm, particular care must be taken in coating and mountingFIG. 1 Applied Voltage Cell (construction drawing)C1202 122the specimens to ensure that the conductive solutions are ableto contact the entire end areas during the test.5. Interferences5.1 This test method can produce misleading res

23、ults 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 penetration,than from tests on identical concrete mixtures (controls)without calcium nitrite. However, long-term chlori

24、de 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 this test similarly.Long term ponding tests are recommended if an admixture effect issuspected.5.2 Since the test r

25、esults are a function of the electricalresistance of the specimen, the presence of reinforcing steel orother embedded electrically conductive materials may have asignificant effect. The test is not valid for specimens containingreinforcing steel positioned longitudinally, that is, providing acontinu

26、ous 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-drainingcontainer with a minimum capacity of 500 mL.6.1.2 Beaker (1000 mL or larger) or other containerCapable of holding

27、concrete specimen(s) and water and offitting into vacuum desiccator (see 6.1.3).6.1.3 Vacuum Desiccator250-mm inside diameter orlarger. Desiccator must allow two hose connections through arubber stopper and sleeve or through a rubber stopper only.Each connection must be equipped with a stopcock.6.1.

28、4 Vacuum Pump or AspiratorCapable of maintaininga pressure of less than 50 mm Hg (6650 Pa) in desiccator.NOTE 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 6 5mmH

29、g (6 665 Pa) over range 0100 mm Hg (013300 Pa)pressure.6.2 Coating Apparatus and Materials:6.2.1 CoatingRapid setting, 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 coatin

30、g.6.3 Specimen Sizing Equipment (not required if samples arecast to final specimen size).6.3.1 Movable Bed Water-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, ag

31、ainstwater and dilute sodium hydroxide and sodium chloridesolutions at temperatures up to 90 C; examples include RTVsilicone rubbers, silicone rubber caulkings, other syntheticrubber sealants, silicone greases, and rubber gaskets.7.2 Sodium Chloride Solution3.0 % by mass (reagentgrade) in distilled

32、water.7.3 Sodium Hydroxide Solution0.3 N (reagent grade) indistilled water.7.3.1 WarningBefore using NaOH, review: (1) the safetyprecautions for using NaOH; (2) first aid for burns; and (3) theemergency response to spills, as described in the manufactur-ers Material Safety Data Sheet or other reliab

33、le safety litera-ture. NaOH can cause very severe burns and injury to unpro-tected skin and eyes. Suitable personal protective equipmentshould always be used. These should include full-face shields,rubber aprons, and gloves impervious to NaOH. Gloves shouldbe checked periodically for pin holes.7.4 F

34、ilter 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)Twosymmetric poly (methyl methacrylate) chambers, each contain-ing electrically conductiv

35、e 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 same asshown in Fig. 1 and width of the screen and shims are asshown.FIG. 2 Vacuum Satura

36、tion Apparatus FIG. 3 Applied Voltage Cell-Face ViewC1202 1237.6 Temperature Measuring Device (optional)0 to 120 Crange.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 accurateto 6 0

37、.1 V and current to 6 1 mA. Apparatus listed in7.7.1-7.7.5 is a possible system meeting this requirement.7.7.1 VoltmeterDigital (DVM), 3 digit, minimum 099.9V range, rated accuracy 6 0.1 %.7.7.2 VoltmeterDigital (DVM), 412 digit, 0200 mVrange, rated accuracy 6 0.1 %.7.7.3 Shunt Resistor100 mV, 10A r

38、ating, tolerance6 0.1 %. Alternatively, a 0.01 V 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 constant at 60 6 0.1 V over entirerange of currents.7.7.5 CableTw

39、o 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 their propor-tions, samples may be (a) cores from test slabs or from largediameter cylinders or (b) 100-mm diameter cast cylinde

40、rs. Forevaluation of structures, samples shall be cores from thestructure. 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/C42M.Cylinders cast in the laboratory shall be prepared followin

41、gprocedures in Practice C192/C192M.NOTE 4The 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 upto 25.0 mm nominal maximum size.8.2 When results of this test

42、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 with Practice C192/C192M for con-crete mixtures prepared in

43、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 cementitious materials useextended moist curing in accordance w

44、ith 8.2.2 (see Note 5)unless the accelerated moist curing method of 8.2.3 is specified(see Note 6). Alternatives to these curing methods and dura-tions are permitted when specified. Use the same method andduration of curing for preparing mixture submittals, for subse-quent acceptance testing, and fo

45、r 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 Extended Moist CuringCure test specimens for 56days in accordance w

46、ith 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

47、 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 in lime-saturated water at 38.0 6 2.0 C.NOTE 5The 56-day moist curing period is to allow for some supple-mentary ce

48、mentitious materials to develop potential properties because oftheir slower rate of hydration. Concrete containing supplementary cemen-titious materials may continue to show reductions in results of this testbeyond 56 days, and in some cases, it may be appropriate to test at laterages, such as 3 mon

49、ths.NOTE 6The accelerated moist curing procedure has been found usefulin providing an earlier indication of potential property development withslower hydrating supplementary cementitious materials (7). Because thetwo different curing methods may not provide the same results, thespecifier of the test may require a correlation between results for extendedmoist cured and accelerated moist cured specimens and establish appro-priate acceptance criteria when the accelerated moist curing procedure isused or permitted. Comparisons between results of