ASTM G109-2007 Standard Test Method for Determining Effects of Chemical Admixtures on Corrosion of Embedded Steel Reinforcement in Concrete Exposed to Chloride Environments《测定混凝土暴露.pdf

1、Designation: G 109 07Standard Test Method forDetermining Effects of Chemical Admixtures on Corrosionof Embedded Steel Reinforcement in Concrete Exposed toChloride Environments1This standard is issued under the fixed designation G 109; the number immediately following the designation indicates the ye

2、ar 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure for determining t

3、heeffects 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 in a chloride environment.1.2 The values stated i

4、n SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.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 he

5、alth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 615/A 615M Specification for Deformed and PlainCarbon-Steel Bars for Concrete ReinforcementC33 Specification for Concrete AggregatesC 143/C 143M Test Method for Slump o

6、f Hydraulic-Cement ConcreteC 150 Specification for Portland CementC 173/C 173M Test Method for Air Content of FreshlyMixed Concrete by the Volumetric MethodC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 231 Test Method for Air Content of Freshly MixedConcrete b

7、y the Pressure MethodC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC 876 Test Method for Half-Cell Potentials of UncoatedReinforcing Steel in ConcreteC 881/C 881M Specification for Epoxy-Resin-Base Bond-i

8、ng Systems for ConcreteC 1152/C 1152M Test Method for Acid-Soluble Chloride inMortar and ConcreteD 448 Classification for Sizes of Aggregate for Road andBridge ConstructionD 632 Specification for Sodium ChlorideE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 691 Practice

9、for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG3 Practice for ConventionsApplicable to ElectrochemicalMeasurements in Corrosion TestingG15 Terminology Relating to Corrosion and CorrosionTestingG33 Practice for Recording Data from Atmospheric Cor-rosion Tests of Me

10、tallic-Coated Steel SpecimensG46 Guide for Examination and Evaluation of PittingCorrosion2.2 NACE Standards:3SSPC-SP 5/NACE No. 1 White Metal Blast Cleaning3. Significance and Use3.1 This test method provides a reliable means for predict-ing the inhibiting or corrosive properties of admixtures to be

11、used in concrete.3.2 This test method is useful for development studies ofcorrosion inhibitors to be used in concrete.3.3 This test method has been used elsewhere with goodagreement between corrosion as measured by this test methodand corrosion damage on the embedded steel (1-4).4This testmethod mig

12、ht not properly rank the performance of differentcorrosion inhibitors, especially at concrete covers over the steelless than 40 mm (1.5 in.) or water-to-cement ratios above 0.45.The concrete mixture proportions and cover over the steel are1This test method is under the jurisdiction of ASTM Committee

13、 G01 onCorrosion of Metals and is the direct responsibility of Subcommittee G01.14 onCorrosion of Metals in Construction Materials.Current edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1992. Last previous edition approved in 2005 as G 10999a(2005).2For referenced ASTM

14、 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.3Available from The Society for Protective Coatings (SSPC), 40 24th St., 6thFloor

15、, Pittsburgh, PA 15222-4656.4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chosen to accelerate chloride ingress. Some inhibitors mighthav

16、e an effect on this process, which could lead to results thatwould differ from what would be expected in actual use (5).4. Apparatus4.1 The apparatus required for the evaluation of corrosioninhibitors includes a high impedance voltmeter (at least oneMohm) capable of measuring to 0.01 mV, a 100 V (65

17、%)resistor.5. Reagents and Materials5.1 Cement, that conforms to Type I or Type II of Specifi-cation C 150. Coarse aggregate shall conform to SpecificationC33and Classification D 448, with nominal maximum sizebetween 9.5 and 19 mm (38 and34 in.).NOTE 1Preferred maximum size aggregate is 12.5 mm (0.5

18、 in.).5.2 Steel Reinforcement Bars, deformed, meeting the re-quirement of Specification A 615/A 615M; with a diameterbetween 10 mm (0.4 in.) and 16 mm (0.6 in.), and a length of360 mm (14 in.), drilled and tapped at one end to be fitted withcoarse-thread stainless steel and nuts, as described in 5.3

19、 and5.4. These bars shall be used to manufacture the test specimens,as described in Section 6.NOTE 2Interlaboratory test program and statistical data in Section 11are based upon 13-mm (0.5-in.) steel bars, 12.5-mm maximum sizeaggregate, and 19-mm (0.75-in.) and 25-mm (1 in.) cover.5.3 316 Stainless

20、Steel Screws, with diameter smaller thanbar diameter (coarse thread5mm(0.2 in.), 25 to 35-mm (1to 1.5-in.) long (one per bar).5.4 316 Stainless Steel Nuts, two per bar to fit stainless steelscrews, as described in 5.3.5.5 Two-part Waterproof Epoxy5,6This epoxy shall meetthe chemical resistance requi

21、rements of a Type IV, Grade 3,Class E of Specification C 881/C 881M.5.6 Sulfuric Acid, 10 % by mass, for pickling (optional).5.7 Electroplaters Tape.6,75.8 Neoprene Tubing, with 3-mm (18-in.) wall thickness andthe same ID as the diameter of the bar used.5.9 Sodium Chloride, complying with Specificat

22、ion D 632.5.10 Salt Solution, prepared by dissolving 3 parts of sodiumchloride (as described in 5.9) in 97 parts of water mass.5.11 Epoxy Sealer, for application to the concrete specimensafter manufacture. This sealer shall be of Type III, Grade 1,Class C in accordance with Specification C 881/C 881

23、M.6,85.12 Plastic Dams, 75-mm (3-in.) wide and 150-mm (6-in.)long with a minimum height of 75 mm (3 in.) for placement onthe test specimens. The wall thickness shall be 61mm(18 6132 in.5.13 Silicone Caulk, for sealing the outside of the plasticdam to the top of the concrete specimen.6,95.14 Referenc

24、e Electrode, such as a saturated calomel orsilver/silver chloride electrode for measuring the corrosionpotential of the bars, as defined in Terminology G15.5.15 Hexane.6. Preparation of Test Specimens6.1 Power wire brush or sand blast the bars to near whitemetal (see SSPC-SP 5/NACE No. 1), clean by

25、soaking inhexane, and allow to air dry.NOTE 3Pickling the bars with 10 % sulfuric acid for 10 to 15 min andrinsing with potable water prior to wire brushing is recommended whenthe bars have an excessive amount of rust.6.2 Use the same method to clean all bars in the testprogram.6.3 Drill and tap one

26、 end of each bar, attach a stainless steelscrew and two nuts, as described in 5.3 and 5.4, and tape eachend of the bar with electroplaters tape so that a 200-mm (8-in.)portion in the middle of the bar is bare. Place a 90-mm (3.5 in.)length of neoprene tubing, as described in 5.8, over theelectroplat

27、ers tape at each end of the bar, and fill the length oftubing protruding from the bar ends with the two-part epoxy, asdescribed in 5.5.6.4 Specimen size is 280 3 150 3 115 mm (11 3 6 34.5 in.). Place two bars, as described in 5.2, 25 mm (1 in.) fromthe bottom, and one bar at the top such that the di

28、stance fromits top to the top surface of the specimen is twice the maximumaggregate size, as shown in Fig. 1.NOTE 4For example, for a 12.5-mm (0.5 in.) aggregate, place the topbar 25 mm (1 in.) from the surface. For a 9.5-mm (0.375-in.) aggregate,place the bar 19 mm (0.75 in.) from the top surface.5

29、The sole source of supply of the apparatus known to the committee at this timeis PC-Epoxy, made by Protective Coating Co., Allentown, PA.6If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at

30、 a meeting of the responsible technical committee,1which you may attend.7The sole source of supply of the apparatus known to the committee at this timeis Minnesota Mining and Manufacturing Company (3M), 1999 Mt. Read Boulevard,Rochester, NY 14615.8The sole source of supply of the apparatus known to

31、the committee at this timeis Epoxy Concrete Scaler # 12560, made by Devcon.9The sole source of supply of the apparatus known to the committee at this timeis 3M Marine Adhesive 5200.NOTEAll measurements in inches (25.4 mm = 1 in.).FIG. 1 Concrete BeamG1090726.5 Place the bars in the molds so that 40

32、mm (approxi-mately 1.5 in.) of the bars are protected within each exit endfrom the concrete (minimizes edge effects). This will expose200 mm (8 in.) of steel. Place the bars with the longitudinal ribsso that they are nearer the side of the beam, that is, both ridgesare equidistant from the top or bo

33、ttom of the specimen.6.6 Make the concrete specimens (controls and those withadmixtures to be tested) in accordance with Practice C 192/C 192M, using the same source of materials. Determine the aircontent, using either Test Method C 231 or C 173/C 173M. Thewater-to-cement ratio (w/c) shall not excee

34、d 0.5. The minimumslump is 50 mm (2 in.) (See Test Method C 143/C 143M).Place and consolidate the concrete in the molds containing thebars in accordance with Practice C 192/C 192M.NOTE 5The concrete parameters used in the interlaboratory test wereas follows: cement content of 355 6 3 kg/m3(600 6 5 l

35、b/yd3), 0.50 60.01 w/c (ssd aggregates), and 6 6 1 % air.6.7 Add the admixture to be tested at the manufacturersrecommended dosages. A water reducer is allowed, if needed,to achieve the desired slump. Record the admixtures used.Except for the test admixtures, use the same admixtures in allmixtures.6

36、.8 A minimum of three replicates shall be made. Make thesame number of replicates per admixture tested and control(see Note 6). An addition cylinder 100 3 200 mm (4 3 8 in.)in diameter shall be produced for background chloride analy-sis.NOTE 6A larger number of replicates is preferred.6.9 Apply a wo

37、od float finish after consolidation. Afterremoval from the forms, cure the specimens for 28 days in amoist room in accordance with Test Method C 192/C 192Mand Specification C511.6.10 Upon removal from the moist room, hand wire brushthe specimens on the concrete top surface (wood floatedsurface). All

38、ow the specimens to dry for two weeks in a 50 %relative humidity (RH) environment before sealing the fourvertical sides with an epoxy sealer, as described in 5.11,inaccordance with the manufacturers recommendation. Place aplastic dam with dimensions, as described in 5.12,onthespecimen, as shown in F

39、ig. 1, and about 13 mm (0.5 in.) fromeach side so that it does not extend over the taped sections ofthe bars (see Fig. 2). Use a silicone caulk to seal the dam fromthe outside, and apply epoxy sealer to the top surface outside ofthe dam.NOTE 7Allowing the specimens to dry before applying the concret

40、eepoxy will make the initial exposure to chloride more severe, and moreclosely follow the interlaboratory test program conditions.6.11 Attach wires and resistors.7. Procedure7.1 Support each test specimen on two nonelectricallyconducting supports at least 13-mm (0.5-in.) thick, thus allow-ing air fl

41、ow under most of the specimen. Start the test onemonth after the samples are removed from the 100 % RHatmosphere (moist room). Pond the specimens for two weeks at23 6 3C (73 6 5F) with the salt solution, as described in5.10. The volume of this solution is approximately 400 mL ata depth of 40 mm (1.5

42、 in.). Use a plastic loose fitting cover tominimize evaporation. Maintain a relative humidity around thespecimens of 50 6 5 %. After two weeks, vacuum off thesolution and allow the samples to dry for two weeks. Repeatthis cycle.7.2 Measure the voltage across the resistor at the beginningof the secon

43、d week of ponding using the voltmeter defined in4.1. Calculate the current, Ij, from the measured voltage acrossthe 100 V resistor, Vj, measured in volts (see Note 8) as:Ij5 Vj/100NOTE 8With the common terminal on the bottom bar, negativevoltages correspond to positive galvanic current (that is, the

44、 top bar is theanode).7.3 At the same time, measure the corrosion potential of thebars against a reference electrode that is placed in the damcontaining the salt solution (see Practice G3and Test MethodC 876). Connect the voltmeter between the reference electrode(ground or common terminal) and the b

45、ars.8. Period of Testing8.1 Monitor the current as a function of time once everyfour weeks, as described in 7.2, until the average integratedmacrocell current of the control specimens is 150 C or greater,as determined in 10.1.8, and at least half the samples showintegrated macrocell currents equal t

46、o or greater than 150 C(see Note 9).NOTE 9The value of 150 C is consistent with a macrocell current of10 A over six months. The value of 10 A was measured by alllaboratories on all specimens showing corrosion (controls and sampleswith calcium chloride at 19-mm (34-in.) cover). This degree of integra

47、tedmacrocell current is sufficient to ensure the presence of sufficientcorrosion for visual evaluation.8.2 In those cases where the admixtures being tested arecorrosive, end the test three full cycles after an averageintegrated macrocell current of 75 C is observed and theintegrated macrocell curren

48、t of at least half the specimensbeing tested is equal or greater than 75 C.NOTEAll measurements in inches (not to scale) (25.4 mm = 1 in.).FIG. 2 Concrete Beam (Side View)G1090739. Examination of Embedded Bars9.1 At the conclusion of testing, break the specimens andexamine the reinforcement bars for

49、 extent of corrosion, mea-sure the corroded area, and record the percentage of corrodedarea recorded, as described in Practice G33.NOTE 10Photograph the bars at the end of the test to provide a recordof the corrosion damage.9.2 Determine the acid soluble chloride content at the depthcorresponding to the cover over the top-reinforcing bar, usingTest Method C 1152/C 1152M.9.3 Determine the acid soluble chloride content in thespecimen produced for background chloride analysis, usingTest Method C 1152/C 1152M. This value is to be subtractedfrom the acid solubl