ASTM_G_180_-_13.pdf

Designation:G18013Standard Test Method forCorrosion Inhibiting Admixtures for Steel in Concrete byPolarization Resistance in Cementitious Slurries1This standard is issued under the fixed designation G180;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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.Scope1.1 This test method covers a procedure for determining theeffects of chemical admixtures on the corrosion of metals inconcrete.This test method can be used to evaluate materialsintended to inhibit chloride-induced corrosion of steel inconcrete.It can also be used to evaluate the corrosivity ofadmixtures by themselves or in a chloride environment.Thistest is not applicable for emulsions.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.Referenced Documents2.1 ASTM Standards:2C150 Specification for Portland CementC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD632 Specification for Sodium ChlorideE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG3 Practice for Conventions Applicable to ElectrochemicalMeasurements in Corrosion TestingG5 Reference Test Method for Making PotentiodynamicAnodic Polarization MeasurementsG59 Test Method for Conducting Potentiodynamic Polariza-tion Resistance MeasurementsG193 Terminology and Acronyms Relating to Corrosion3.Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice see Terminology G193.4.Significance and Use4.1 This test method provides a means for assessingcorrosion-inhibiting concrete admixtures.4.2 This test method is useful for development of admix-tures intended to reduce corrosion of reinforcing steel inconcrete.4.3 This test method is useful in determining the corrosivityof admixtures toward steel reinforcing if the admixture sampleis compared to a control without admixtures.4.4 Good performance,a reduction in corrosion rate versuschloride alone by at least one order of magnitude in this test,isa strong indication that an admixture is a corrosion inhibitor.However,poor performance requires additional testing todetermine if the admixture improves corrosion resistance.4.5 This test method shall not be used to predict perfor-mance in the field.4.6 The filtering process makes this test not suitable for theevaluation of emulsions.5.Apparatus5.1 The test cell as described in Test Method G5.5.2 Potentiostat,as described in Test Method G5,capable ofvarying potential at a constant scan rate and measuring theresulting current.5.3 A method of recording the varying potential and result-ing current is needed.5.4 Electrode holder such as described in Fig.3 of TestMethod G5.5.5 Electrodes:5.5.1 Working electrode,prepared from a 12.7 mm length of9.5 mm diameter rod stock.Carbon steel C1215 should beused.NOTE1If specimen forms are used other than those called for by thistest method,for example flat sheet specimens,care should be taken not tointroduce crevices which can lead to erroneous results.1This test method is under the jurisdiction of ASTM Committee G01 onCorrosion of Metals and is the direct responsibility of Subcommittee G01.14 onCorrosion of Metals in Construction Materials.Current edition approved May 1,2013.Published May 2013.Originallyapproved in 2004.Last previous edition approved in 2007 as G180 07.DOI:10.1520/G0180-13.2For 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 Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.6 Auxiliary ElectrodesTwo graphite rods or platinized-niobium or platinum mesh.5.7 Reference ElectrodesA saturated calomel electrodewith a controlled rate of leakage(about 3 L/h)is recom-mended.6.Reagents and Materials6.1 Type I/II cement(C3A content between 6 and 10%),according to Specification C150.6.2 Filter paper with 1.1 m retention.6.3 PTFE stir bars.6.4 Carbon steel C1215 samples,cylindrical in shape,with5.1 cm2exposed area.36.5 Sodium chloride,reagent grade,according to Specifica-tion D632.6.6 Calcium hydroxide,reagent grade.6.7 Admixtures to be tested.6.8 Carbon dioxide free compressed air.47.Experimental Procedure7.1 Prepare a cement slurry consisting of 1000 g of waterand 200 g cement.Mix thoroughly,stir for 60 min and filter.NOTE2An admixtu