1、Designation: C 1152/C 1152M 04e1Standard Test Method forAcid-Soluble Chloride in Mortar and Concrete1This standard is issued under the fixed designation C 1152/C 1152M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEA typo in the equation in paragraph 9.1 was corrected editorially February 2006.1. Scope1.1 This test method2provides procedu
3、res for the samplingand analysis of hydraulic-cement mortar or concrete forchloride that is acid soluble under the conditions of test. Inmost cases, acid-soluble chloride is equivalent to total chloride.1.2 The text of this standard references notes and footnotesthat provide explanatory information.
4、 These notes and foot-notes shall not be considered as requirements of this standard.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 an
5、d determine the applica-bility of regulatory limitations prior to use.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theinch-pound units are shown in brackets. The values stated ineach system are not exact equivalents; therefor
6、e, each systemshall be used independently of the other.2. Referenced Documents2.1 ASTM Standards:3C 42/C 42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC114 Test Methods for Chemical Analysis of HydraulicCementC 670 Practice for Preparing Precision and Bias Stateme
7、ntsfor Test Methods for Construction MaterialsC 702 Practice for Reducing Samples of Aggregate toTesting SizeC 823 Practice for Examination and Sampling of HardenedConcrete in ConstructionsC 1084 Test Method for Portland-Cement Content of Hard-ened Hydraulic-Cement ConcreteD 1193 Specification for R
8、eagent WaterE11 Specification for Wire Cloth and Sieves for TestingPurposes3. Significance and Use3.1 The amount of acid-soluble chloride in most hydraulic-cement systems is equal to the total amount of chloride in thesystem. However, some organic substances that may be intro-duced into mortar or co
9、ncrete contain chloride that is initiallyacid-insoluble that can eventually ionize and thus becomeacid-soluble or water-soluble after a period of exposure in thevery alkaline cement system.3.2 Sulfides are known to interfere with the determination ofchloride content. Blast-furnace slag aggregates an
10、d cementscontain sulfide sulfur in concentrations that can cause suchinterference and produce erroneously high test results. Treat-ment with hydrogen peroxide, as discussed in Test MethodsC114, is used to eliminate such interference.3.3 There are aggregates that contain chloride that is notavailable
11、 for corrosion. Such chloride will be detected by theuse of this method.44. Apparatus4.1 Sampling Equipment4.1.1 The apparatus required for obtaining samples bycoring or sawing is described in Test Method C 42/C 42M.4.1.2 Use the following apparatus for sampling by drilling(pulverization):4.1.2.1 Ro
12、tary Impact Drill and drill or pulverizing bits ofsufficient diameter to provide a representative sample ofsufficient size for testing.4.1.2.2 Spoon or other suitable means to remove pulverizedsample material from drill hole without contamination.4.1.2.3 Sample Containers capable of maintaining samp
13、lesin an uncontaminated state.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.69 on Miscellaneous Tests.Current edition approved June 1, 2004. Published July 2004. Originally approvedin 1990. Las
14、t previous edition approved in 2003 as C 1152 03.2This test method is based on a report by Clear, K. C., and Harrigan, E. T.,“Sampling and Testing for Chloride Ion in Concrete,” Report No. FHWA-RD77-85,Federal Highway Administration, Washington, DC, Aug. 1977 (Available as PB275-428/AS National Tech
15、nical Information Services).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.4For more information, see “The D
16、etermination of the Chloride Content ofConcrete,” by Brian B. Hope, John A. Page and John S. Poland, Cement andConcrete Research, Volume 15, Number 5, Pergamon Press, New York, September1985, pp. 863-870.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
17、959, United States.4.2 Sample Processing ApparatusThe apparatus requiredfor processing samples shall be chosen for its suitability for thepurposes of the investigation, and frequently includes a con-crete saw and one or more pulverizers.4.2.1 Samples more than 25 mm (1 in.) in maximumdimension shall
18、 be reduced in size by use of a jaw crusher orbroken into smaller pieces by hammering carefully to avoidloss of smaller pieces.4.2.2 Crush particles less than 25 mm (1 in.) in maximumdimension using a rotating puck grinding apparatus, or byusing a disk pulverizer, or mortar and pestle operated to re
19、strictto negligible levels the loss of fine particles.4.2.3 Sieve, 850-m No. 20, which shall comply withSpecification E11.4.3 Chloride Determination4.3.1 Balance, shall be capable of reproducing resultswithin 0.0002 g with an accuracy of 6 0.0002 g. Direct-reading balances shall have a sensitivity n
20、ot exceeding 0.0001g. Conventional two-pan balances shall have a maximumsensibility reciprocal of 0.0003 g. Any rapid weighing devicethat may be provided, such as a chain, damped motion, orheavy riders, shall not increase the basic inaccuracy by morethan 0.0001 g at any reading and with any load wit
21、hin the ratedcapacity of the balance.4.3.2 Stirrer, magnetic variable speed, with a TFE-fluorocarbon coated magnetic stirring bar.4.3.3 Chloride, Silver/Sulfide Ion Selective Electrode,orasilver billet electrode coated with silver chloride (see Note 1)with an appropriate reference electrode.4.3.4 Po
22、tentiometer, with millivolt scale readable to 1 mVor better. A digital readout is preferred but not required.NOTE 1See Note 67 of Test Methods C114 for a discussion ofsuitable electrodes and coating methods.4.4 Glazed PaperPaper to which fine particles do notadhere, for use as described in 7.1.5. Re
23、agents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee onAnalytical Reagents of theAmerican Chemical Society5.Other grades may be used, provided it is first ascer
24、tained thatthe reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.5.1.1 Sodium Chloride (NaCl).5.1.2 Silver Nitrate (AgNO3).5.1.3 Potassium Chloride (KCl), (required for silver billetelectrode only).5.1.4 Reagent Water conforming to the requir
25、ements ofSpecification D 1193 for Type III reagent water.5.1.5 Sodium Chloride, Standard Solution (0.05 N NaCl)Dry sodium chloride at 105 to 110 C to a constant mass.Weigh 2.9222 g of dried reagent. Dissolve in water and diluteto exactly 1 L in a volumetric flask and mix thoroughly. Thissolution is
26、the standard and requires no further standardization.5.1.6 Silver Nitrate, Standard Solution (0.05 N (AgNO3)Dissolve 8.4938 g of silver nitrate in water. Dilute to 1 L in avolumetric flask and mix thoroughly. Standardize against 5.00mL of standard 0.05 N sodium chloride solution diluted to 150mL wit
27、h water following the titration test method given in 8.1beginning with the second sentence. The exact normality shallbe calculated from the average of three determinations asfollows:N = 0.25/V, where:N = normality of AgNO3solution,0.25 = milliequivalents NaCl (5.0 3 0.05 N), andV = volume of AgNO3so
28、lution, mL.Commercially available standard solutions may be used pro-vided the normality is checked according to the standardizationprocedure.5.1.7 Methyl Orange IndicatorPrepare a solution contain-ing2gofmethyl orange per litre of 95 % ethyl alcohol.5.1.8 Nitric Acid (1+1).5.1.9 Hydrogen Peroxide (
29、30 %).6. Sampling6.1 Select the sample per Practice C 823 or as required forthe purpose of the investigation.6.1.1 Because of the small nominal maximum size of theaggregate in a mortar, pieces of mortar having a mass of 10 gor more will be representative of a rather large volume ofmortar.6.1.2 Take
30、concrete cores in accordance with Test MethodC 42/C 42M unless otherwise specified.NOTE 2Concrete cores taken in accordance with Test Method C 42/C 42M may be cut longitudinally to provide a 12-mm 12-in. thick sectiongenerally representative of the core, or cut laterally into 12-mm 12-in.thick disks
31、 representative of the concrete core at various depths. Concretefarthest from a surface into which chloride has penetrated often provideschloride data close to that of the originally placed fresh concrete. Thecooling water from core cutting may dissolve some of the chloride.6.1.3 Powdered concrete o
32、btained by use of a rotary impactdrill is frequently used in determining chloride concentrationwith depth in bridge decks, pavements, etc. Such samples maybe unrepresentative, especially when the nominal maximumcoarse aggregate size is 25 mm 1 in. or more. Thus, severalsuch samples should be combine
33、d, or the data used with care.Procedures for this method of sampling are as follows:6.1.3.1 Using the rotary impact drill, drill perpendicular tothe concrete surface or parallel to the axis of a cored specimento a specified depth or a depth sufficient to obtain a represen-tative sample of the concre
34、te mixture of at least 20 g ofpowdered material. To prevent sample contamination, avoidcontact of sample with hands and other sources of perspiration.Clean all sampling tools prior to each sampling operation (SeeNote 3). No lubricants shall be used during drilling.NOTE 3Sampling tools may be cleaned
35、 with a brush, cloth, ethyl5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and t
36、he United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.C 1152/C 1152M 04e12alcohol rinse, water rinse, or other method that will not contaminate thesample.6.1.3.2 Transfer powdered sample into sample containerusing a spoon or other suitable mea
37、ns.7. Sample Preparation7.1 Pulverize the sample so that all the material will pass a850-m No. 20 sieve. Thoroughly blend the material byconing as described in Practice C 702 from one glazed paper toanother at least 10 times.8. Procedure8.1 Determine the mass of approximately 10 g of sample tothe ne
38、arest 0.01 g and transfer to a 250 mL beaker. Disperse thesample with 75 mL of water. Slowly add 25 mL of dilute (1+1)nitric acid and stir with a glass rod, breaking up any lumps ofsample. If the smell of hydrogen sulfide is strongly present, add3 mL of hydrogen peroxide (See Note 4). Add 3 drops of
39、methyl orange indicator to the beaker and stir. Cover the beakerwith a watch glass and allow to stand for 1 to 2 minutes. If thesolution above the settled solids is not pink colored, add morenitric acid dropwise while stirring until a pink or reddish colorpersists, then add 10 additional drops of ni
40、tric acid and stir.Heat the covered beaker rapidly to boiling and remove fromhot plate. Do not allow sample to boil more than a few seconds(See Note 5). Make a blank determination using 75 mL ofwater in place of sample.NOTE 4Slags and slag cements contain sulfide sulfur in concentra-tions that can i
41、nterfere with chloride determination unless oxidized withhydrogen peroxide.NOTE 5To prevent loss of chloride by volatilization, it is important tokeep the beaker covered during heating and digestion. Ten seconds ofboiling is sufficient. Excessive amounts of acid can erode the silverchloride coating
42、on the silver billet electrode prematurely. A slurry that isonly slightly acidic is sufficient.8.2 Filter the sample through a 9-cm coarse-textured filterpaper in a 250 mL or 500 mL Buchner funnel and filtrationflask using suction. Rinse the beaker and the filter paper twicewith small portions of wa
43、ter. Transfer the filtrate from the flaskto a 250 mL beaker and rinse the flask once with water. Theoriginal beaker may be used (See Note 6). Cool the filtrate toroom temperature. The volume should not exceed 175 mL.NOTE 6It is not necessary to clean all the slurry residue from the sidesof the beake
44、r, nor is it necessary that the filter remove all the fine material.The titration may take place in a solution that contains a small amount ofsolid matter.8.3 For instruments equipped with a dial readout it isnecessary to establish an approximate 9equivalence point9 byimmersing the electrodes in a b
45、eaker of water and adjusting theinstrument to read about 20 mV lower than mid-scale. Recordthe approximate millivoltmeter reading. Remove the beakerand wipe the electrodes with absorbent paper.8.4 Pipet 2.00 mL of standard 0.05 N NaCl solution into thecooled sample beaker (See Note 7). Place the bea
46、ker on amagnetic stirrer and add a TFE-fluorocarbon coated stir bar.Immerse the electrodes into the solution, taking care that thestir bar does not strike the electrodes. Begin stirring gently.Place the delivery tip of the 10 mL buret filled to the zero markwith standardized 0.05 N AgNO3in (preferab
47、ly) or above thesample solution (See Note 8).NOTE 7It is advisable to maintain constant temperature duringmeasurement, as the solubility of silver chloride varies markedly withtemperature at low concentrations.NOTE 8If the tip of the buret is out of the solution, any adheringdroplet should be rinsed
48、 into the beaker with a few millilitres of waterfollowing each titration increment.8.5 Gradually titrate, record the amount of standard 0.05 Nsilver nitrate solution required to bring the millivoltmeterreading to -60.0 mV of the equivalence point determined in thewater.8.6 Continue the titration wit
49、h 0.20 mL increments. Recordthe buret reading and the corresponding millivoltmeter reading.Allow sufficient time between each addition for the electrodesto reach equilibrium with the sample solution (See Note 9).NOTE 9Experience has shown that acceptable readings are obtainedwhen the minimum scale reading does not change within a 5-s period.8.7 As the equivalence point is approached, the equaladditions of silver nitrate solution will cause larger and largerchanges in the millivoltmeter readings. Past the equivalencepoint, the change per increment will
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