1、Designation: C1202 17aC1202 18Standard 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 rev
2、ision, the 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 electrical conductance of concrete to provide a r
3、apid indication of itsresistance to the penetration of chloride ions. This test method is applicable to types of concrete where correlations have beenestablished between this test procedure and long-term chloride ponding procedures such as those described in AASHTO T 259.Examples of such correlation
4、s are discussed in Refs 1-5.21.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes(excluding those in tab
5、les and figures) shall not be considered as requirements of the standard.1.4 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 safety, health, and healthenvironme
6、ntal practices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guid
7、es and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3C31/C31M Practice for Making and Curing Concrete Test Specimens in the FieldC42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams
8、 of ConcreteC192/C192M Practice for Making and Curing Concrete Test Specimens in the LaboratoryC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsC802 Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods
9、for ConstructionMaterials2.2 AASHTO Standard:T 259 Method of Test for Resistance of Concrete to Chloride Ion Penetration43. Summary of Test Method3.1 This test method consists of monitoring the amount of electrical current passed through 50-mm thick slices of 100-mmnominal diameter cores or cylinder
10、s during a 6-h period. A potential difference of 60 V dc is maintained across the ends of thespecimen, one of which is immersed in a sodium chloride solution, the other in a sodium hydroxide solution. The total chargepassed, in coulombs, has been found to be related to the resistance of the specimen
11、 to chloride ion penetration.1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.66 onConcretes Resistance to Fluid Penetration.Current edition approved Dec. 1, 2017July 1, 2018. Published Decembe
12、r 2017October 2018. Originally approved in 1991. Last previous edition approved in 2017 as C1202 17.17a. DOI: 10.1520/C1202-17A.10.1520/C1202-18.2 The boldface numbers in parentheses refer to the list of references at the end of this standard.3 For referencedASTM standards, visit theASTM website, ww
13、w.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 Methods of Sampling and Testing, 1986, American Association of State Highway and Transportation Officials, 444 N. Ca
14、pitol St., NW, Washington, DC 20001.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM rec
15、ommends 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 official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C
16、700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 This test method covers the laboratory evaluation of the electrical conductance of concrete samples to provide a rapidindication of their resistance to chloride ion penetration. In most cases the electrical conductance r
17、esults have shown goodcorrelation with chloride ponding tests, such as AASHTO T259, on companion slabs cast from the same concrete mixtures (Refs1-5).4.2 This test method is suitable for evaluation of materials and material proportions for design purposes and research anddevelopment.4.3 Sample age h
18、as significant effects on the test results, depending on the type of concrete and the curing procedure. Mostconcretes, if properly cured, become progressively and significantly less permeable with time.4.4 This test method was developed originally for evaluations of alternative materials, but in pra
19、ctice its use has evolved toapplications such as quality control and acceptance testing. Factors such as ingredient materials used in concrete mixtures and themethod and duration of curing test specimens affect the results of this test (See(see Note 1). When this method is used for mixturequalificat
20、ion and acceptance testing, it is imperative that the curing procedures and the age at time of testing be clearly specified.NOTE 1When using this test for determining acceptability of concrete mixtures, statistically-based criteria and test age for prequalification, or foracceptance based on jobsite
21、 samples, should be stated in project specifications. Acceptance criteria for this test should consider the sources of variabilityaffecting the results and ensure balanced risk between supplier and purchaser. The anticipated exposure conditions and time before a structure will beput into service sho
22、uld be considered. One approach to establishing criteria is discussed in Ref 6.4.5 Table X1.1 in Appendix X1 provides a qualitative relationship between the results of this test and the chloride ionpenetrability of concrete.4.6 Care should be taken in interpreting results of this test when it is use
23、d on surface-treated concretes, for example, concretestreated with penetrating sealers. The results from this test on some such concretes indicate low resistance to chloride ionpenetration, while 90-day chloride ponding tests on companion slabs show a higher resistance.4.7 The details of the test me
24、thod apply to 100-mm nominal diameter specimens. This includes specimens with actual diametersranging from 95 to 100 mm. Other specimen diameters may be tested with appropriate changes in the applied voltage cell design(see 7.5 and Fig. 1).4.7.1 For specimen diameters other than 95 mm, the test resu
25、lt value for total charge passed must be adjusted following theprocedure in 11.2. For specimens with diameters less than 95 mm, particular care must be taken in coating and mounting thespecimens to ensure that the conductive solutions are able to contact the entire end areas during the test.5. Inter
26、ferences5.1 This test method can produce misleading results when calcium nitrite has been admixed into a concrete. The results fromthis test on some such concretes indicate higher coulomb values, that is, lower resistance to chloride ion penetration, than fromtests on identical concrete mixtures (co
27、ntrols) without calcium nitrite. However, long-term chloride ponding tests indicate theconcretes with calcium nitrite were at least as resistant to chloride ion penetration as the control mixtures.NOTE 2Other admixtures might affect results of this test similarly. Long term ponding tests are recomme
28、nded if an admixture effect is suspected.5.2 Since the test results are a function of the electrical resistance of the specimen, the presence of reinforcing steel or otherembedded electrically conductive materials may have a significant effect. The test is not valid for specimens containing reinforc
29、ingsteel positioned longitudinally, that is, providing a continuous electrical path between the two ends of the specimen.6. Apparatus6.1 Vacuum Saturation Apparatus (see Fig. 2 for example):6.1.1 Separatory Funnel, or other sealable, bottom-draining container with a minimum capacity of 500 mL.6.1.2
30、Beaker (1000 mL or larger) or other containerCapable of holding concrete specimen(s) and water and of fitting intovacuum desiccator (see 6.1.3).6.1.3 Vacuum DesiccatorThe volume of desiccator shall be large enough to maintain sample immersion throughout thesaturation process. Desiccator must allow t
31、wo hose connections through 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 maintaining a an absolute pressure of less than 50 mm Hg (6650 Pa) indesiccator.desiccator (see Note 4).NOTE 3SinceBecaus
32、e vacuum will be drawn over water, a vacuum pump should be protected with a water trap, or pump oil should be changed aftereach operation.NOTE 4Absolute pressure is zero-referenced against a perfect vacuum. At sea level, atmospheric pressure is an absolute pressure of 760 mm Hg.Gauge pressure is zer
33、o-referenced against atmospheric air pressure, so it is equal to the absolute pressure minus atmospheric pressure. An absolutepressure of 50 mm Hg will correspond to a gauge pressure of -710 mm at sea level. Some gauges may display this value as +710 mm.6.1.5 Vacuum Gage or ManometerAccurate to the
34、nearest 65 mm Hg (6665 Pa) over range 0100 mm Hg (013300 Pa) theentire of measured pressure.C1202 1826.2 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, and
35、Disposable BrushesFor mixing and applying coating.6.3 Specimen Sizing Equipment (not required if samples are cast to final specimen size).6.3.1 Movable Bed Water-Cooled Diamond Saw or Silicon Carbide Saw.7. Reagents, Materials, and Test Cell7.1 Specimen-Cell SealantCapable of sealing concrete to pol
36、y (methyl methacrylate), for example, Plexiglas, against waterand dilute sodium hydroxide and sodium chloride solutions at temperatures up to 90 C; 90C; examples include RTV siliconerubbers, silicone rubber caulkings, other synthetic rubber sealants, silicone greases, and rubber gaskets.7.2 Sodium C
37、hloride Solution3.0 % by mass (reagent grade) in distilled water.7.3 Sodium Hydroxide Solution0.3 N (reagent grade) in distilled water.7.3.1 Bring the NaOH solution to room temperature prior to use (Note 45).FIG. 1 Applied Voltage Cell (Construction Drawing)C1202 183NOTE 5Mixing 0.3 N NaOH solution
38、generates heat, affecting the conductivity of the solution and the results of the test.7.3.2 WarningBefore using NaOH, review: (1) the safety precautions for using NaOH; (2) first aid for burns; and (3) theemergency response to spills, as described in the manufacturers Material Safety Data Sheet or
39、other reliable safety literature.NaOH can cause very severe burns and injury to unprotected skin and eyes. Suitable personal protective equipment should alwaysbe used. These should include full-face shields, rubber aprons, and gloves impervious to NaOH. Gloves should be checkedperiodically for pin h
40、oles.7.4 Filter PapersNo. 2, 90-mm diameter (not required if rubber gasket is used for sealant (see 7.1) or if sealant can be appliedwithout overflowing from shim onto mesh).7.5 Applied Voltage Cell (see Fig. 1 and Fig. 3)Two symmetric poly (methyl methacrylate) chambers, each containingelectrically
41、 conductive mesh and external connectors. One design in common use is shown in Fig. 1 and Fig. 3. However, otherdesigns are acceptable, provided that overall dimensions (including dimensions of the fluid reservoir) are the same as shown inFig. 1 and width of the screen and shims are as shown.7.6 Tem
42、perature Measuring Device (optional)0 to 120C range.7.7 Voltage Application and Data Readout ApparatusCapable of holding 60 6 0.1 V dc across applied voltage cell over entirerange of currents and of displaying voltage accurate to 60.1 V and current to 61 mA.Apparatus listed in 7.7.1 7.7.5 is a possi
43、blesystem meeting this requirement.7.7.1 VoltmeterDigital (DVM), 3 digit, minimum 099.9 V range, rated accuracy 60.1 %.7.7.2 VoltmeterDigital (DVM), 412 digit, 0200 mV range, rated accuracy 60.1 %.7.7.3 Shunt Resistor100 mV, 10Arating, tolerance 6 0.1 %.Alternatively, a 0.01resistor, tolerance 6 0.1
44、 %, may be used,but care must be taken to establish very low resistance 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 entire rangeof currents.7.7.5 CableTwo conductor, AWG No. 14 (1.6 mm), insulated, 600 V.FIG. 2 Vacuum Saturat
45、ion ApparatusFIG. 3 Applied Voltage Cell-Face ViewC1202 1848. Test Specimens8.1 Sample preparation and selection depends on the purpose of the test. For evaluation of materials or their proportions,samples may be (a) cores from test slabs or from large diameter cylinders or (b) 100-mm diameter cast
46、cylinders. For evaluationof structures, samples shall be cores from the structure. Coring shall be done with a drilling rig equipped with a 100-mm diameterdiamond-dressed core bit. Select and core samples following procedures in Test Method C42/C42M. Cylinders cast in thelaboratory shall be prepared
47、 following procedures in Practice C192/C192M.NOTE 6The maximum allowable aggregate size has not been established for this test. Users have indicated that test repeatability is satisfactory onspecimens from the same concrete batch for aggregates up to 25.0 mm nominal maximum size.8.2 When results of
48、this test method are used for evaluation of materials or mixture proportions based on cast specimens forpurposes of quality control, mixture submittals, or acceptance of concrete, prepare at least two 100-mm diameter cylindricalspecimens in accordance with Practice C192/C192M for concrete mixtures p
49、repared in the laboratory or Practice C31/C31M fromsamples of fresh concrete obtained in the field. Moist cure specimens in accordance with 8.2.1 for concrete mixtures containingonly portland cement. For concrete mixtures containing supplementary cementitious materials use extended moist curing inaccordance with 8.2.2 (see Note 67) unless the accelerated moist curing method of 8.2.3 is specified (see Note 78). Alternativesto these curing methods and durations are permitted when specified. Use the same method and duration of curing for pr
