1、Standard Method of Test for Determining Chloride Ions in Concrete and Concrete Materials by Specific Ion Probe AASHTO Designation: T 332-07 (2016)1 Release: Group 1 (April 2016) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.
2、C. 20001 TS-3c T 332-1 AASHTO Standard Method of Test for Determining Chloride Ions in Concrete and Concrete Materials by Specific Ion Probe AASHTO Designation: T 332-07 (2016)1Release: Group 1 (April 2016) 1. SCOPE 1.1. This method covers the procedures for determining acid-soluble chloride ions in
3、 concrete and concrete mix ingredients. 1.2. The age of concrete, mortar, or hydrated portland cement at the time of sampling will have an effect on the acid-soluble chloride ion content. Therefore, unless early age studies are desired, it is recommended that the material be well cured and at least
4、28 days of age before sampling. 1.3. This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and heal
5、th practices and to determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 92, Wire-Cloth Sieves for Testing Purposes M 231, Weighing Devices Used in the Testing of Materials T 260, Sampling and Testing for Chloride Ion in Concrete and Co
6、ncrete Raw Materials 2.2. ASTM Standards: D1193, Standard Specification for Reagent Water E1, Standard Specification for ASTM Liquid-in-Glass Thermometers 3. SUMMARY OF TEST METHOD 3.1. A 3.0-g drilled concrete powder sample is digested in 20 mL of an acid digestion solution and stabilized by the ad
7、dition of 80 mL of a stabilizing solution. Millivolt readings, taken for the sample solution using a specific chloride ion probe, are converted mathematically into equivalent total percent chloride content or chloride content in kg/m3(lb/yd3) of concrete. 4. INTERFERENCES 4.1. The operational respon
8、se of the specific ion electrode is subject to interference by the presence of OH, S2, Br, I, and CNin the measured solution and is based on the electrode manufacturers allowable chloride interference ratio. 2016 by the American Association of State Highway and Transportation Officials.All rights re
9、served. Duplication is a violation of applicable law.TS-3c T 332-2 AASHTO 4.2. Sulfides are known to interfere with the determination of chloride in solution. This test procedure is, therefore, unsuitable for determining the chloride content of concrete containing mineral aggregates containing signi
10、ficant quantities of pyrite. 5. SIGNIFICANCE AND USE 5.1. This method provides a rapid means of sampling and testing for total chloride ions in concrete in the field. 6. APPARATUS 6.1. Impact HammerA heavy-duty rotary impact hammer with a drilling stop gauge is used. See Figures 1 through 3. Figure
11、1Overall View of the Drilling Stop Gauge to Be Mounted on the Impact Hammer 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-3 AASHTO Note: All dimensions shown in millimeters unless otherwise
12、 noted. Figure 2Details of the Split Ring Collar for the Drilling Stop Gauge Note: All dimensions shown in millimeters unless otherwise noted. Figure 3Details of the Depth Rods for the Drilling Stop Gauge 2016 by the American Association of State Highway and Transportation Officials.All rights reser
13、ved. Duplication is a violation of applicable law.TS-3c T 332-4 AASHTO 6.2. BitA vacuum bit with a diameter equivalent to 1.5 times the maximum aggregate size in the concrete is used. A 28-mm (1.25-in.) bit size is recommended for a maximum coarse aggregate size of 19 mm (0.75 in.). The bit grinds t
14、he concrete to a fineness of 99 percent passing the 850-m (No. 20) sieve conforming to M 92. The finely ground powder is drawn into the collection unit through a coaxial hole in the bit. 6.3. Sample Collection UnitA cylindrical polymethyl methacrylate vacuum chamber is connected to the carbide bit t
15、hrough a vacuum hose for sample collection. Vacuum is provided by a 2.25-HP wet/dry shop vacuum unit. Figures 4 through 8 present the details of the sample collection unit that is to be attached to the wet/dry shop vacuum unit. 6.4. FilterAn inexpensive coffee filter is adequate for collecting the p
16、owdered concrete samples in the polymethyl methacrylate chamber. 6.5. Plastic Bottles/ContainersWidemouth polypropylene bottles with screw caps in the following two sizes are needed: 6.5.1. For calibration solutions and for storing powdered concrete samples: 30 mL. 6.5.2. For digestion solution: 125
17、 mL. 6.6. Weighing Papers76 by 76 mm (3 by 3 in.) weighing papers are needed for determining the mass of the powdered concrete samples. 6.7. SpatulaA stainless steel small spoon spatula is needed for transferring small quantities of the powdered concrete samples from the plastic container for mass d
18、eterminations. 6.8. BalancesAn electronic balance sensitive to 0.1 g is needed to determine the mass of the specimens. An electronic balance sensitive to 0.0001 g is needed to determine the mass of sodium chloride for the calibration and stabilizing solutions. 2016 by the American Association of Sta
19、te Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-5 AASHTO Legend Name 1. Collection cylinder 2. Ring 3. Vacuum cylinder 4. Cap 5. Clamp Note: All dimensions shown in millimeters unless otherwise noted. Figure 4Sample Collection Uni
20、t 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-6 AASHTO Details of Cap Name Required Material 1. Entry cylinder 1 Plexiglas 2. Cap base 1 Plexiglas Note: All dimensions shown in millimeter
21、s unless otherwise noted. Figure 5Sample Collection Unit (Details of Cap) Details of Ring Name Required Material 1. Ring 1 Plexiglas Note: All dimensions shown in millimeters unless otherwise noted. Figure 6Sample Collection Unit (Details of Ring) 2016 by the American Association of State Highway an
22、d Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-7 AASHTO Details of Collection Cylinder and Vacuum Cylinder Name Required Material 1. Collection cylinder 1 Plexiglas 2. Vacuum cylinder 1 Plexiglas Note: All dimensions shown in millimeters unle
23、ss otherwise noted. Figure 7Sample Collection Unit (Details of Collection Cylinder and Vacuum Cylinder) 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-8 AASHTO Details of Clamp (2 required)
24、Name Required Material 1. Spacer 2 Rubber 2. Shaft 1 Steel 3. Nut 1 Steel 4. Spring pin 1 Steel Note: All dimensions shown in millimeters unless otherwise noted. Figure 8Sample Collection Unit (Details of Clamp) 6.9. Specific Chloride Ion ElectrodeThe specific ion electrode for measuring the chlorid
25、e ion concentration in solution must conform to the following specifications: 6.9.1. Concentration measuring range 5 105to 1 mol or 1.8 to 35 mg/L. 6.9.2. The electrode resistance shall be less than 1.0 M. 6.9.3. Reproducibility shall be 2 percent. 6.9.4. Operating temperature range shall be 10 to 1
26、00C by thermometers specified in ASTM E1. Note 1A suitable specific chloride ion electrode is the Orion Combination Chloride Electrode Model 96-17B with chamber filling solution number 900017 (for use with chloride solution concentrations up to 355 mg/L). 6.10. MultimeterThe multimeter used in the p
27、rocedure must conform to the following specifications: 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 332-9 AASHTO 6.10.1. Maximum common mode voltage shall be 1500 VDC or peak AC; 6.10.2. Resol
28、ution at minimal range shall be 100 V; 6.10.3. Accuracy shall be (0.25 percent of the reading + 1 digit); 6.10.4. Operating temperature range shall be 0 to 50C (32 to 122F); and 6.10.5. Input impedance shall be greater than 2.0 M. Note 2The Orion Model 250A is a suitable meter. 7. MATERIALS AND REAG
29、ENTS 7.1. Sodium ChlorideReagent grade. 7.2. Ethyl AlcoholReagent grade. 7.3. Acetic AcidGlacial acetic acid having the following properties: Note 3In the use of acetic acid, the operator must use caution to avoid injuries to hands and eyes. Wear safety goggles and gloves. 7.3.1. Specific gravity at
30、 25C 1.05. 7.3.2. Chloride content: 0.4 mg/L. 7.3.3. Normality: 17.4. 7.4. Isopropyl AlcoholReagent grade having the following properties: 7.4.1. Specific Gravity at 25C: 0.781 to 0.783. 7.4.2. Boiling Point: 82.3 0.1C. 7.5. Distilled WaterDistilled water conforming to ASTM D1193, Type IV. 7.6. Conc
31、rete SamplesThe concrete sample to be analyzed shall be in powdered form, 99 percent passing the 850-m (No. 20) sieve, as taken from the rotary impact hammer extraction procedure. 7.7. Digestion SolutionThe digestion solution is prepared by combining acetic acid, isopropyl alcohol, and distilled wat
32、er. Take 800 mL of distilled water in a 1-L measuring flask, and add 60 mL of glacial acetic acid and 60 mL of isopropyl alcohol to the flask. Thoroughly stir the solution and make up the volume to 1 L by adding distilled water. Allow the solution to cool to room temperature. Dispense the solution i
33、n 20-mL volumes into the 125-mL polypropylene bottles. 7.8. Calibration SolutionsThe calibration solutions are prepared by dissolving sodium chloride in distilled water. The concentration levels are 1.25, 0.6, 0.3, 0.03, and 0.01 percent chloride ions by mass of concrete, based on a 3.0-g concrete s
34、ample. To obtain the respective concentration levels, dissolve the following quantities of sodium chloride each in 1 L of distilled water: 0.6169 g, 0.2961 g, 0.1481 g, 0.0148 g, and 0.0049 g. (This will result in solutions with chloride ion concentrations of 374, 180, 90, 9, and 3 mg/L, respectivel
35、y, which in turn correspond to the above-noted percentages by mass of concrete.) Dispense 20 mL of each of the calibration solutions into a separate 30-mL polypropylene bottle, and label each bottle accordingly. 2016 by the American Association of State Highway and Transportation Officials.All right
36、s reserved. Duplication is a violation of applicable law.TS-3c T 332-10 AASHTO 7.9. Stabilizing SolutionThe stabilizing solution is a diluted standard chloride solution. It is prepared as follows: Dissolve 0.1545 g of sodium chloride in distilled water in a 1-L flask and make up the volume to 1 L wi
37、th distilled water. Take 40 mL of this solution and dilute it further to 1 L by adding distilled water. 7.10. Solution TemperatureThe temperature of the solution during testing significantly affects the determined chloride concentration. To minimize errors caused by temperature variations, ensure th
38、at the calibration, digestion, and stabilizing solutions are maintained at 22.2 1.1C (72 2F). 8. FIELD SAMPLING 8.1. Obtain a sample from the concrete structure using the rotary impact hammer with depth gauge and the carbide vacuum bit. 8.2. Using the sample collection unit, collect at least 10.0 g
39、of powdered concrete in the filter. A hole, drilled about 28.6 mm (11/8in.) in diameter and 12.7 mm (1/2in.) deep, will yield approximately 25 g of powdered concrete sample. 8.3. Place the filter containing the sample in the 30-mL polypropylene bottle. 9. CALIBRATION PROCEDURE 9.1. The measurement o
40、f the calibration solutions determines the response characteristics of the specific ion electrode in combination with the multimeter. Mathematical regression of the responses produces a representative equation for the combination used to determine the chloride contents of powdered concrete samples.
41、A minimum of five calibration solution concentrations is needed to adequately calibrate the equipment combination. Any alterations to equipment combinations shall require recalibration and the formulation of a new calibration equation. 9.2. Determine the electrode response to chloride ion concentrat
42、ion of the calibration solutions as described below. Start with the calibration solution with the lowest chloride ion concentration. 9.2.1. Place chloride ion electrode halfway into the calibration solution, and wait for 3 min to allow the millivolt reading to stabilize. The millivolt reading is sta
43、ble when it oscillates by less than 0.5 mV. Record at least five readings and calculate average value to be used for determining the calibration equation. 9.2.2. Repeat the above process (Step 9.2.1) for each of the remaining calibration solutions. 9.3. The calibration equation is determined as foll
44、ows: 9.3.1. Calculate the log10of the mg/L chloride concentrations of the calibration solutions, e.g., log10(374 mg/L Cl) = 2.573. 9.3.2. Perform a linear regression of the millivolt responses (X) versus the log10of the chloride concentrations of the respective calibration solutions (Y), producing E
45、quation 1 in the following format: log10(mg/L Cl) = constant + coefficient mV (1) Note 4The constant and coefficient will vary with varying equipment combinations. However, the constant is numerically characterized by x.xxx and the coefficient is characterized by 0.0xxx, where x represents digits. T
46、he slope should be between 54 and 60 mV/decade at 25C. If not, consult the troubleshooting section of the electrode operation manual or the manufacturer. 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.T
47、S-3c T 332-11 AASHTO 9.3.3. The percent chloride is determined from the logarithmic inverse of the regression equation (Equation 1) minus the chloride added by the stabilizing solution, converted to percent chloride by mass of concrete, as follows in Equation 2: 0.0 mV%Cl = 10 3.0 mg/L (0.00333)x xx
48、x xxx+(2) 9.4. Although unnecessary for calibration, measurements of the calibration solutions, at both the beginning and the end of testing, are recommended as a check on the operational integrity of the instrument combination. A deviation in the calibration solution millivolt response indicates a
49、problem involving one or more of the following: 9.4.1. Contamination of calibration solutions; 9.4.2. Contamination of the internal filling solution of the specific ion electrode; 9.4.3. Defective specific ion electrode; and 9.4.4. Defective multimeter. 9.5. The percent chloride is based on a 3.0-g powdered concrete sample, and the mg/L chloride is the resulting concentration of a 100-mL solution. The allowable deviations of the specific ion electrode for various chloride ion concentrations
