1、Designation: C1202 10Standard 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 inch-pound units are to be regardedas the standard, except where SI units are given first followedby inch-pound units in parentheses. The values given inparentheses are for information only.1.3 This standard does not purport to address all of thesafety con
5、cerns, 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. Referenced Documents2.1 ASTM Standards:3C31/C31M Practice for Making and Curin
6、g Concrete TestSpecimens in the FieldC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC192/C192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Mat
7、erials2.2 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 amount ofelectrical current passed through 2-in. (51-mm) thick slices of4-in. (102-mm) nominal diameter cores or cylinders d
8、uring a6-h period. A potential difference of 60 V dc is maintainedacross the ends of the specimen, one of which is immersed ina sodium 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 ch
9、loride 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 resistance to chloride ion penetration. Inmost cases the electrical conductance results have shown goodcorrelation
10、 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 proportions for design purposes and research anddevelopment.4.3 Sample age has significant effects on the test
11、 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 developed originally for evalua-tions of alternative materials, but in practice its use has evolvedto applica
12、tions such as quality control and acceptance testing.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.66 on Concretes Resistance to Fluid Penetration.Current edition approved Feb. 1, 2010. Publish
13、ed March 2010. Originallyapproved in 1991. Last previous edition approved in 2009 as C1202 09. DOI:10.1520/C1202-10.2The boldface numbers 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 Cus
14、tomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Methods of Sampling and Testing, 1986, American Association of StateHighway and Transportation Officials, 444 N. Capitol St., NW, Washington, DC2000
15、1.1*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 19428-2959, United States.In such cases it is imperative that the curing procedures and theage at time of testing be clearly specified.4.5 Tabl
16、e 1 provides a qualitative relationship between theresults of this test and the chloride ion penetrability ofconcrete.4.6 Numerical results of this test (total charge passed, incoulombs) can be used as a basis for determining the accept-ability of a concrete mixture. Factors such as the ingredientma
17、terials used and method and duration of curing of testspecimens affect results of this test. (See Note 1)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
18、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 conditions and time before astructure will be put into service should be considered. O
19、ne approach toestablishing criteria is discussed in Ref 6.4.7 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 thistest on some such concretes indicate low resistance to chl
20、orideion penetration, while 90-day chloride ponding tests on com-panion slabs show a higher resistance.4.8 The details of the test method apply to 4-in. (102-mm)nominal diameter specimens. This includes specimens withactual diameters ranging from 3.75 in. (95 mm) to 4.0 in. (102mm). Other specimen d
21、iameters may be tested with appropriatechanges in the applied voltage cell design (see 7.5 and Fig. 1).4.8.1 For specimen diameters other than 3.75 in. (95 mm),the test result value for total charge passed must be adjustedfollowing the procedure in 11.2. For specimens with diametersless than 3.75 in
22、. (95 mm), particular care must be taken incoating and mounting the specimens to ensure that the con-ductive solutions are able to contact the entire end areas duringthe test.5. Interferences5.1 This test method can produce misleading results whencalcium nitrite has been admixed into a concrete. The
23、 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 chloride pondingtests indicate the concretes with calcium nitrite we
24、re 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 results are a function of the electricalresistance of the speci
25、men, 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 acontinuous electrical path between the two ends of the speci-men.6. A
26、pparatus6.1 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 concrete specimen(s) and water and offitting into vacuum desic
27、cator (see 6.1.3).6.1.3 Vacuum Desiccator250-mm (9.8-in.) inside diam-eter or larger. Desiccator must allow two hose connectionsthrough a rubber stopper and sleeve or through a rubber stopperonly. Each connection must be equipped with a stopcock.6.1.4 Vacuum Pump or AspiratorCapable of maintaininga
28、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 5mmHg (6 665 Pa) over range 0100 mm Hg (013300 Pa)pres
29、sure.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 coating.6.3 Specimen Sizing Equipment (not required if s
30、amples 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, againstwater and dilute sodium hydroxide and sodium
31、chloridesolutions at temperatures up to 200 F (90 C); examplesinclude RTV silicone rubbers, silicone rubber caulkings, othersynthetic rubber 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 (
32、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 reliable safety litera-ture. NaOH can cause very
33、 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.TABLE 1 Chloride Ion Penetrability Based on Cha
34、rge Passed (1)Charge Passed (coulombs) Chloride Ion Penetrability4,000 High2,0004,000 Moderate1,0002,000 Low1001,000 Very Low100 NegligibleC1202 1027.4 Filter PapersNo. 2, 90-mm (3.5-in.) diameter (notrequired if rubber gasket is used for sealant (see 7.1)orifsealant can be applied without overflowi
35、ng from shim ontomesh).7.5 Applied Voltage Cell (see Fig. 1 and Fig. 3)TwoFIG. 1 Applied Voltage Cell (construction drawing)FIG. 2 Vacuum Saturation ApparatusFIG. 3 Applied Voltage Cell-Face ViewC1202 103symmetric poly (methyl methacrylate) chambers, each contain-ing electrically conductive mesh and
36、 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.7.6 Temperature Measuring Devi
37、ce (optional)30to250F (0 to 120 C) range.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 0.1 V and current to 6 1 mA. Apparatus listed in7.7.1-7.7.5 is a possible system
38、 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 rating, tolerance6 0.1 %. Alternatively, a 0.01 V resistor, tolerance 6 0.1 %,ma
39、y 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 CableTwo conductor, No. 14 (1.6 mm), insulated,600 V.8. Test Specimens8.1 Sample prepa
40、ration 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) 4-in. (102-mm) diameter cast cylin-ders. For evaluation of structures, samples may be (a) coresfrom the structu
41、re or (b) 4-in. (102-mm) diameter cylinderscast and cured at the field site. Coring shall be done with adrilling rig equipped with a 4-in. (102-mm) diameter diamond-dressed core bit. Select and core samples following proceduresin Test Method C42/C42M. Cylinders cast in the laboratoryshall be prepare
42、d following procedures in Practice C192/C192M. When cylinders are cast in the field to evaluate astructure, care must be taken that the cylinders receive thesame treatment as the structure, for example, similar degree ofconsolidation, curing, and temperature history during curing.NOTE 4The maximum a
43、llowable 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 (1 in.) nominal maximum size.8.2 When results of this test method are used for evaluationof materials or
44、mixture proportions based on cast specimens forpurposes of quality control, mixture submittals, or acceptanceof concrete, prepare 4-in (102-mm) diameter cylindrical speci-mens in accordance with Practice C192/C192M for concretemixtures prepared in the laboratory or Practice C31/C31Mfrom samples of f
45、resh concrete obtained in the field. Unlessotherwise specified, moist cure specimens in accordance with8.2.1 for concrete mixtures containing only portland cementand in accordance with 8.2.2 for concrete mixtures containingsupplementary cementitious materials. Use the same methodand duration of curi
46、ng test specimens when comparing two ormore mixtures. The accelerated moist curing procedure in 8.2.3is permitted as an alternative to the extended moist curingprocedure for concrete mixtures containing supplementarycementitious materials (See Note 6).8.2.1 Moist CuringCure test specimens for at lea
47、st 28days in accordance with Practice C192/C192M or in accor-dance with the standard curing procedure of Practice C31/C31M for specimens prepared in the field.8.2.2 Extended Moist CuringCure test specimens for atleast 56 days in accordance with Practice C192/C192M forspecimens prepared in the labora
48、tory or in accordance with thestandard curing procedure of Practice C31/C31M for speci-mens prepared 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 proced
49、ure 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(100 6 3 F).NOTE 5The 56-day moist curing period is to allow for some supple-mentary cementitious 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, su
