ASTM G109-99a(2005)
(Test Method)Standard Test Method for Determining the Effects of Chemical Admixtures on the Corrosion of Embedded Steel Reinforcement in Concrete Exposed to Chloride Environments
Standard Test Method for Determining the Effects of Chemical Admixtures on the Corrosion of Embedded Steel Reinforcement in Concrete Exposed to Chloride Environments
SIGNIFICANCE AND USE
This test method provides a reliable means for predicting the inhibiting or corrosive properties of admixtures to be used in concrete.
This test method is useful for development studies of corrosion inhibitors to be used in concrete.
This test method has been used elsewhere with good agreement between corrosion as measured by this test method and corrosion damage on the embedded steel (1, 2, 3, 4).4 This test method might not properly rank the performance of different corrosion inhibitors, especially at concrete covers over the steel less than 40 mm (1.5 in.) or water-to-cement ratios above 0.45. The concrete mixture proportions and cover over the steel are chosen to accelerate chloride ingress. Some inhibitors might have an effect on this process, which could lead to results that would differ from what would be expected in actual use (5).
SCOPE
1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures in a chloride environment.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are provided for information only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:G109–99a (Reapproved 2005)
Standard Test Method for
Determining the Effects of Chemical Admixtures on the
Corrosion of Embedded Steel Reinforcement in Concrete
Exposed to Chloride Environments
This standard is issued under the fixed designation G 109; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope C 876 Test Method for Half-Cell Potentials of Uncoated
Reinforcing Steel in Concrete
1.1 This test method covers a procedure for determining the
C 881/C 881M Specification for Epoxy-Resin-Base Bond-
effects of chemical admixtures on the corrosion of metals in
ing Systems for Concrete
concrete. This test method can be used to evaluate materials
C 1152/C 1152M Test Method for Acid-Soluble Chloride
intended to inhibit chloride-induced corrosion of steel in
in Mortar and Concrete
concrete. It can also be used to evaluate the corrosivity of
D 448 Classification for Sizes of Aggregate for Road and
admixtures in a chloride environment.
Bridge Construction
1.2 The values stated in SI units are to be regarded as the
D 632 Specification for Sodium Chloride
standard. The inch-pound units in parentheses are provided for
E 177 Practice for Use of the Terms Precision and Bias in
information only.
ASTM Test Methods
1.3 This standard does not purport to address all of the
E 691 Practice for Conducting an Interlaboratory Study to
safety concerns, if any, associated with its use. It is the
Determine the Precision of a Test Method
responsibility of the user of this standard to establish appro-
G3 PracticeforConventionsApplicabletoElectrochemical
priate safety and health practices and determine the applica-
Measurements in Corrosion Testing
bility of regulatory limitations prior to use.
G15 Terminology Relating to Corrosion and Corrosion
2. Referenced Documents
Testing
G33 Practice for Recording Data from Atmospheric Cor-
2.1 ASTM Standards:
rosion Tests of Metallic-Coated Steel Specimens
A 615/A 615M Specification for Deformed and Plain
G46 Guide for Examination and Evaluation of Pitting
Billet-Steel Bars for Concrete Reinforcement
Corrosion
C33 Specification for Concrete Aggregates
2.2 NACE Standards:
C 143/C 143M Test Method for Slump of Hydraulic Ce-
SSPC SP 5 (NACE No. 1) White Metal Blast Cleaning
ment Concrete
C 150 Specification for Portland Cement
3. Significance and Use
C 173/C 173M Test Method for Air Content of Freshly
3.1 This test method provides a reliable means for predict-
Mixed Concrete by the Volumetric Method
ing the inhibiting or corrosive properties of admixtures to be
C 192/C 192M Practice for Making and Curing Concrete
used in concrete.
Test Specimens in the Laboratory
3.2 This test method is useful for development studies of
C 231 Test Method for Air Content of Freshly Mixed
corrosion inhibitors to be used in concrete.
Concrete by the Pressure Method
3.3 This test method has been used elsewhere with good
C511 Specification for Mixing Rooms, Moist Cabinets,
agreement between corrosion as measured by this test method
Moist Rooms, and Water Storage Tanks Used in the
and corrosion damage on the embedded steel (1, 2, 3, 4). This
Testing of Hydraulic Cements and Concretes
test method might not properly rank the performance of
different corrosion inhibitors, especially at concrete covers
over the steel less than 40 mm (1.5 in.) or water-to-cement
This test method is under the jurisdiction of ASTM Committee G01 on
Corrosion, Deterioration, and Degradation of Materials and is the direct responsi-
ratios above 0.45. The concrete mixture proportions and cover
bility of Subcommittee G01.14 on Metals in Construction Materials.
Current edition approved May 1, 2005. Published May 2005. Originally
approved in 1992. Last previous edition approved in 1999 as G 109 – 99a .
e1
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from Society for Protective Coatings (SSPC), 40 24th St., 6th Floor,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Pittsburgh, PA 15222-4656.
Standards volume information, refer to the standard’s Document Summary page on The boldfaced numbers in parentheses refer to the list of references at the end
the ASTM website. of this test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
G109–99a (2005)
over the steel are chosen to accelerate chloride ingress. Some 5.11 EpoxySealer,forapplicationtotheconcretespecimens
inhibitors might have an effect on this process, which could after manufacture. This sealer shall be of Type III, Grade 1,
lead to results that would differ from what would be expected Class C in accordance with Specification C 881/C 881M.
in actual use (5). 5.12 Plastic Dams, 75-mm (3-in.) wide and 150-mm (6-in.)
long with a minimum height of 75 mm (3 in.) for placement on
4. Apparatus
the test specimens. The wall thickness shall be 61mm( ⁄8 6
⁄32 in.
4.1 The apparatus required for the evaluation of corrosion
5.13 Silicone Caulk, for sealing the outside of the plastic
inhibitors includes a high impedance voltmeter (at least one
dam to the top of the concrete specimen.
Mohm) capable of measuring to 0.01 mV, a 100-ohm (65%)
5.14 Reference Electrode, such as a saturated calomel or
resistor.
silver/silver chloride electrode for measuring the corrosion
5. Reagents and Materials
potential of the bars, as defined in TerminologyG15.
5.15 Hexane
5.1 Cement, that conforms to Type I or Type II of Specifi-
cation C 150. Coarse aggregate shall conform to Specification
6. Preparation of Test Specimens
C33 and Classification D 448, with nominal maximum size
3 3 6.1 Power wire brush or sand blast the bars to near white
between 9.5 and 19 mm ( ⁄8 and ⁄4 in.).
metal (see Specification SSPC SP-50), clean by soaking in
NOTE 1—Preferred maximum size aggregate is 12.5 mm (0.5 in.).
hexane, and allow to air dry.
5.2 Steel Reinforcement Bars, deformed, meeting the re-
NOTE 3—Pickling the bars with 10 % sulfuric acid for 10 to 15 min and
quirement of Specification A 615/A 615M; with a diameter
rinsing with potable water prior to wire brushing is recommended when
between 10 mm (0.4 in.) and 16 mm (0.6 in.), and a length of
the bars have an excessive amount of rust.
360 mm (14 in.), drilled and tapped at one end to be fitted with
6.2 Use the same method to clean all bars in the test
coarse-thread stainless steel and nuts, as described in 5.3 and
program.
5.4.Thesebarsshallbeusedtomanufacturethetestspecimens,
6.3 Drill and tap one end of each bar, attach a stainless steel
as described in Section 6.
screw and two nuts, as described in 5.3 and 5.4, and tape each
NOTE 2—Interlaboratory test program and statistical data in Section 11
endofthebarwithelectroplater’stapesothata200-mm(8-in.)
are based upon 13-mm (0.5-in.) steel bars, 12.5-mm maximum size
portion in the middle of the bar is bare. Place a 90-mm (3.5 in.)
aggregate, and 19-mm (0.75-in.) and 25-mm (1 in.) cover
length of neoprene tubing, as described in 5.8, over the
5.3 316 Stainless Steel Screws, with diameter smaller than
electroplater’s tape at each end of the bar, and fill the length of
bar diameter (coarse thread<5mm (0.2 in.)), 25 to 35-mm (1
tubingprotrudingfromthebarendswiththetwo-partepoxy,as
to 1.5-in.) long (one per bar).
described in 5.5.
5.4 316 Stainless Steel Nuts, two per bar to fit stainless steel
NOTE 4—For example, for a 12.5-mm (0.5 in.) aggregate, place the top
screws, as described in 5.3.
bar 25 mm (1 in.) from the surface. For a 9.5-mm (0.375-in.) aggregate,
5.5 Two-part Waterproof Epoxy — This epoxy shall meet
place the bar 19 mm (.75 in.) from the top surface.
the chemical resistance requirements of a Type IV, Grade 3,
6.4 Specimen size is 280 3 150 3115mm(11 3 6 3 4.5
Class E of Specification C 881/C 881M.
in.).
5.6 Sulfuric Acid, 10 % by mass, for pickling (optional).
6.5 Place the bars in the molds so that 40 mm (approxi-
5.7 Electroplater’s Tape
mately 1.5 in.) of the bars are protected within each exit end
5.8 NeopreneTubing, with 3-mm ( ⁄8-in.) wall thickness and
from the concrete (minimizes edge effects). This will expose
the same ID as the diameter of the bar used.
200mm(8in.)ofsteel.Placethebarswiththelongitudinalribs
5.9 Sodium Chloride, complying with Specification D 632.
so that they are nearer the side of the beam, that is, both ridges
5.10 Salt Solution, prepared by dissolving 3 parts of sodium
are equidistant from the top or bottom of the specimen.
chloride (as described in 5.9) in 97 parts of water mass.
6.6 Make the concrete specimens (controls and those with
admixtures to be tested) in accordance with Practice C 192/
The sole source of supply of the apparatus known to the committee at this time
is PC-Epoxy made by Protective Coating Co., Allentown, PA. If you are aware of
The sole source of supply of the apparatus known to the committee at this time
alternative suppliers, please provide this information to ASTM International
is Epoxy Concrete Scaler # 12560 made by Devcon. If you are aware of alternative
Headquarters.Your comments will receive careful consideration at a meeting of the
suppliers, please provide this information to ASTM International Headquarters.
responsible technical committee , which you may attend.
Your comments will receive careful consideration at a meeting of the responsible
Minnesota Mining and Manufacturing Company (3M), 1999 Mt. Read Boule-
technical committee , which you may attend.
vard, Rochester, NY 14615, has been found suitable for this purpose. If you are
The sole source of supply of the apparatus known to the committee at this time
aware of alternative suppliers, please provide this information to ASTM Interna-
is 3M Marine Adhesive 5200. If you are aware of alternative suppliers, please
tional Headquarters.Your comments will receive careful consideration at a meeting
provide this information toASTM International Headquarters. Your comments will
of the responsible technical committee , which you may attend.
receive careful consideration at a meeting of the responsible technical committee ,
which you may attend.
G109–99a (2005)
C 192M, using the same source of materials. Determine the air
content,usingeitherTestMethodC 231orC 173/C 173M.The
water-to-cementratio(w/c)shallnotexceed0.5.Theminimum
slump is 50 mm (2 in.) (See Test Method C 143/C 143M).
Place and consolidate the concrete in the molds containing the
bars in accordance with Practice C 192/C 192M.
NOTE 5—The concrete parameters used in the inter-laboratory test were
3 3
as follows: cement content of 355 6 3 kg/m (600 6 5 lb/yd ), 0.50 6
0.01 w/c (ssd aggregates), and 6 6 1 % air.
6.7 Add the admixture to be tested at the manufacturer’s
recommended 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 all
mixtures.
6.8 Aminimum of three replicates shall be made. Make the
same 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
NOTE—All measurements in in. (not to scale) (25.4 mm = 1 in.).
chloride analysis.
FIG. 2 Concrete Beam (Side View)
NOTE 6—A larger number of replicates is preferred.
6.9 Apply a wood float finish after consolidation. After
removal from the forms, cure the specimens for 28 days in a epoxy will make the initial exposure to chloride more severe, and more
closely follow the interlaboratory test program conditions.
moist room in accordance with Test Method C 192/C 192M
and SpecificationC511.
6.11 Attach wires and resistors.
6.10 Upon removal from the moist room, hand wire brush
the specimens on the concrete top surface (wood floated
7. Procedure
surface). Allow the specimens to dry for two weeks in a 50 %
7.1 Support each test specimen on two nonelectrically
relative humidity (RH) environment before sealing the four
conducting supports at least 13-mm (0.5-in.) thick, thus allow-
vertical sides with an epoxy sealer, as described in 5.11,in
ing air flow under most of the specimen. Start the test one
accordance with the manufacturer’s recommendation. Place a
month after the samples are removed from the 100 % RH
plastic dam with dimensions, as described in 5.12,onthe
atmosphere(moistroom).Pondthespecimensfortwoweeksat
specimen, as shown in Fig. 1, and about 13 mm (0.5 in.) from
23 6 3°C (73 6 5°F) with the salt solution, as described in
each side so that it does not extend over the taped sections of
5.10. The volume of this solution is approximately 400 mL at
the bars (see Fig. 2). Use a silicone caulk to seal the dam from
a depth of 40 mm (1.5 in.). Use a plastic loose fitting cover to
theoutside,andapplyepoxysealertothetopsurfaceoutsideof
minimize evaporation. Maintain a relative humidity around the
the dam.
specimens of 50 6 5 %. After two weeks, vacuum off the
NOTE 7—Allowing the specimens to dry before applying the concrete
solution and allow the samples to dry for two weeks. Repeat
this cycle.
7.2 Measure the voltage across the resistor at the beginning
of the second week of ponding using the voltmeter defined in
4.1. Calculate the current, I, from the measured voltage across
j
the 100-ohm resistor, V, measured in volts (see Note 8) as:
j
I 5 V /100
j j
NOTE 8—With the common terminal on the bottom bar, negative
voltages correspond to positive galvanic current (that is, the top bar is the
anode).
7.3 At the same time, measure the corrosion potential of the
bars against a reference electrode that is placed in the dam
containing the salt solution (see PracticeG3 and Test Method
C 876). Connect the voltmeter between the reference electrode
(ground or common terminal) and the bars.
8. Period of Testing
8.1 Monitor the current as a function of time once every
four weeks, as described in 7.2, until the average integrated
NOTE—All measurements in in. (25.4 mm = 1 in.).
FIG. 1 Concrete Beam macrocell current of the control specimens is 150 C or greater,
G109–99a (2005)
as determined in 10.1.8, and at least half the samples show
where:
integrated macrocell currents equal to or greater than 150 C
TC = total corrosion (coulombs),
(see Note 9).
t = time (seconds) at which measurement of the macro-
j
cell current is carried out, and
NOTE 9—The value of 150 C is consistent with a macrocell current of
i = macrocell current (amps) at time, t.
j j
10 µA over six mon
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