ASTM A882/A882M-96e1
(Specification)Standard Specification for Epoxy-Coated Seven-Wire Prestressing Steel Strand
Standard Specification for Epoxy-Coated Seven-Wire Prestressing Steel Strand
SCOPE
1.1 This specification covers ASTM Specification A 416 low-relaxation Grade 250 and Grade 270 seven-wire prestressing steel strand with protective fusion-bonded epoxy coating applied by the electrostatic deposition method or other method that will meet the coating requirements in Section 7.
Note 1—The manufacturer as identified throughout this specification is the coating applicator.
1.2 Supplementary Requirements S1 contains requirements for epoxy-coated and filled strand. Epoxy-coated and filled strand shall not be furnished unless ordered, or by arrangement between purchaser and manufacturer.
Note 2—This standard is a product specification and it does not delineate requirements regarding the use of epoxy-coated strand. Proper use of epoxy-coated strand includes design considerations, handling, installing, and stressing of strands, permissible concrete curing temperature, and procedures for repairing damaged coating and protection of the ends of strands. Information and procedures for such items are presented in a report by the PCI Ad Hoc Committee on Epoxy-Coated Strand.
1.3 This specification is applicable for orders in either inch-pound units (as Specification A 882) or SI units [as Specification A 882M].
1.4 The values stated in either inch-pound or SI units are to be regarded as standard. Within the test, the SI units are shown in brackets. The values stated in each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.
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e1
Designation: A 882/A882M – 96
Standard Specification for
Epoxy-Coated Seven-Wire Prestressing Steel Strand
This standard is issued under the fixed designation A 882/A882M; 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.
e NOTE—Editorial corrections were made in June 2001.
1. Scope Seven-Wire for Prestressed Concrete
B 117 Practice for Operating Salt Spray (Fog) Apparatus
1.1 This specification covers ASTM Specification A 416
D 968 Test Methods for Abrasion Resistance of Organic
low-relaxation Grade 250 and Grade 270 seven-wire prestress-
Coatings by Falling Abrasive
ing steel strand with protective fusion-bonded epoxy coating
G 14 Test Method for Impact Resistance of Pipeline Coat-
applied by the electrostatic deposition method or other method
ings (Falling Weight Test)
that will meet the coating requirements in Section 7.
G 20 Test Method for Chemical Resistance of Pipeline
NOTE 1—The manufacturer as identified throughout this specification is 7
Coatings
the coating applicator.
2.2 Federal Highway Administration Report:
1.2 Supplementary Requirements S1 contains requirements
FHWA-RD-74-18 Nonmetallic Coatings for Concrete Rein-
for epoxy-coated and filled strand. Epoxy-coated and filled
forcing Bars (February 1974)
strand shall not be furnished unless ordered, or by arrangement
3. Ordering Information
between purchaser and manufacturer.
3.1 The purchaser should specify:
NOTE 2—This standard is a product specification and it does not
3.1.1 Diameter, grade, and type of uncoated strand in
delineate requirements regarding the use of epoxy-coated strand. Proper
accordance with Specification A 416/A 416M (latest edition).
use of epoxy-coated strand includes design considerations, handling,
installing, and stressing of strands, permissible concrete curing tempera-
3.1.2 Smooth or grit impregnated coating (see 6.3).
ture, and procedures for repairing damaged coating and protection of the
3.1.3 Quantity (in feet [metres]).
ends of strands. Information and procedures for such items are presented
3.1.4 Requirements for certification (see Section A1.2.3).
in a report by the PCI Ad Hoc Committee on Epoxy-Coated Strand.
3.1.5 Requirements for material samples (see 4.3).
1.3 This specification is applicable for orders in either
3.1.6 Requirements for patching material (see 4.4).
inch-pound units (as Specification A 882) or SI units [as
NOTE 3—A typical ordering description for epoxy-coated strand is as
Specification A 882M].
follows: 84 000 feet [2560 m] of grit-impregnated epoxy-coated strand,
1.4 The values stated in either inch-pound or SI units are to
⁄2-in. [12.7-mm] diameter, Grade 270 K low-relaxation on wooden reels
be regarded as standard. Within the test, the SI units are shown
to ASTM Specification A 882 – [A 882M – ].
in brackets. The values stated in each system must be used
4. Materials
independently of the other. Combining values from the two
systems may result in nonconformance with this specification.
4.1 Prestressing steel strand to be coated shall meet the
requirements of Specification A 416/A 416M as specified by
2. Referenced Documents
the purchaser and shall be free of contaminants such as oil,
2.1 ASTM Standards:
grease, or paint.
A 370 Test Methods and Definitions for Mechanical Testing
4.1.1 Epoxy-coated strand shall have relaxation losses of
of Steel Products
not more than 4 % when initially loaded to 70 % of specified
A 416/A 416M Specification for Steel Strand, Uncoated
minimum breaking strength of the strand after 1000 h when
tested under conditions of Specification A 416/A 416M.
4.2 The coating material shall meet the requirements listed
in Annex A1 of this specification. The coating material shall be
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
A01.05 on Steel Reinforcement.
Annual Book of ASTM Standards, Vol 01.04.
Current edition approved March 10, 1996. Published May 1996. Originally
Annual Book of ASTM Standards, Vol 03.02.
published as A 882/A 882M – 91. Last previous edition A 882/A 882M – 95.
Annual Book of ASTM Standards, Vol 06.01.
“Guidelines for the Use of Epoxy-Coated Strand,” PCI Journal, Precast/
Annual Book of ASTM Standards, Vol 06.02.
Prestressed Concrete Institute, Vol. 38, No. 4, July-August 1993, pp. 26–32.
Available from the National Technical Information Service, 5285 Port Royal
Annual Book of ASTM Standards, Vol 01.03.
Rd., Springfield, VA 22161.
Copyright © ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
A 882/A882M
of organic composition except for the pigment, or grit if the crown of the wires, on a straight length of the strand. The
applicable, which may be inorganic if used. magnetic gage shall be placed at one point in the strand and
4.2.1 If specified in the order, a written certification shall be readings shall be taken at the crown of each outer wire.
furnished to the purchaser that properly identifies the number
7.1.4 For each reel of strand, thickness measurements shall
of each batch of coating material used in the order, material,
be conducted at five locations spaced approximately even
quantity represented, date of manufacture, name and address of
along the manufactured length of the strand. Records of
manufacturer, a statement that the supplied coating material
inspection during manufacturing shall be available when re-
meets the requirements of Annex A1, and a statement that the
quested.
coating material used in each batch is the same material as that
7.2 Continuity of Coating:
which was qualified under the requirements of Annex A1.
7.2.1 After curing, the coating shall be free of holes, voids,
4.3 If specified in the order, a representative 8-oz. [0.23-kg]
cracks, and damaged areas discernible to the unaided eye.
sample of coating material shall be packaged in an airtight
7.2.2 During the coating process, a continuous holiday
container and identified by batch number, and supplied to the
detection procedure shall be employed using an appropriate
purchaser.
holiday detector that uses water as the conductor and follows
4.4 If specified in the order, patching material compatible
the procedure furnished by the manufacturer of the holiday
with the coating material and inert in concrete, and meeting the
detector. (A holiday is a pinhole in the coating not discernible
requirements of Annex A1 shall be supplied to the purchaser.
to the unaided eye.)
7.2.3 During the continuous holiday detection procedure, if
5. Surface Preparation
more than two holidays per hundred feet [30 m] are detected,
5.1 The surface of the steel strand to be coated shall be
the strand shall be rejected and corrective action shall be
cleaned chemically or by another method that will impart the
instituted. Coated strand with two holidays or less per hundred
same cleanliness to ensure that the coated strand meets the
feet [30 m] shall be patched in accordance with the patching
requirements of Section 7.
material manufacturer’s recommendation.
7.3 Adhesion of Coating:
6. Application of Coating
7.3.1 The adhesion and shear strength of the coating shall be
6.1 The coating shall be applied to the cleaned surface as
evaluated by bending a sample from a finished reel of coated
soon as possible after cleaning and before reoxidation of the
strand 180° around a mandrel diameter equal to 32 times the
surface discernible to the unaided eye occurs. However, in no
nominal diameter of the strand. Test specimens shall be at
case shall application of the coating be delayed more than 10
thermal equilibrium between 68 and 86°F [20 and 30°C].
minutes after cleaning, unless otherwise permitted by the
7.3.2 No cracking or disbonding of the coating shall be
purchaser.
visible to the unaided eye on the outside radius of the bent
6.2 The coating shall be applied by the electrostatic depo-
strand. Evidence of cracking or disbonding of the coating shall
sition method, or other method that will meet the coating
be considered cause for rejection of the coated strand repre-
requirements in Section 7, and fully cured in accordance with
sented by the bend test sample. Retests shall be conducted in
the recommendations of the manufacturer of the coating
accordance with 9.1.
material.
7.3.3 Fracture of the steel wire or strand in the bend test for
6.3 The coating may be smooth or grit-impregnated.
adhesion of coating shall not be considered as an adhesion
6.3.1 Inert particles (grit) shall be impregnated into the
failure of the coating, and another specimen from the same
surface of the coating when grit-impregnated strand is ordered.
production shift may be substituted.
Such particles shall not cause the coating to fail the require-
7.3.4 The adhesion of coating shall also be evaluated by a
ments of Section 7. The particles shall be inert in concrete and
tension test in accordance with Section 6 of Specification
non-reactive with concrete additives and soluble salts.
A 416. The coated strand shall satisfy the requirements for
6.3.2 The epoxy on the surface of grit-impregnated strand
breaking strength, yield strength (1 % extension), and ultimate
shall be capable of reaching a temperature of 150°F [66°C]
elongation described in Specification A 416/A 416M. No
without reducing the transfer of prestress by bond from the
cracks visible to the unaided eye shall occur in the coating up
strand to the surrounding concrete.
to an elongation of 1 % (yield strength).
NOTE 4—Warning: At temperatures above 165°F [74°C], currently
7.3.5 Sample length for the bend test shall be at least 5 ft, 0
available epoxy begins to soften and lose its ability to transfer load from
in. long [1500 mm]. Sample length for the tension test shall
strand to concrete by bond. At 200°F [93°C] practically all transfer
follow the requirements of Test Methods and Definitions
capacity will be lost.
A 370.
7. Requirements for Coated Strands
7.4 Bond with Concrete or Grout:
7.1 Thickness of Coating: 7.4.1 Pull-out tests shall be conducted on grit-impregnated
7.1.1 The film thickness of the coating after curing shall be coated strand to ensure proper bond properties. Pull-out speci-
25 to 45 mils [0.64 to 1.14 mm]. mens shall be cast in concrete cylinders with dimensions
7.1.2 The thickness of the coating film shall be determined shown in Table 1. The untensioned strand shall be embedded
with a magnetic gauge or other method, with 65 % allowable concentrically along the longitudinal axis of the specimen. The
error, capable of measuring along a curved surface. minimum force at 0.001 in. [0.025 mm] slip shall be applied as
7.1.3 The thickness of the coating film shall be measured on shown in Fig. 1, by a hydraulic or mechanical jack when
A 882/A882M
TABLE 1 Requirements for Pull-Out Tests
there is no unnecessary interference with the manufacturer’s
operation.
Minimum Force
Cylinder Embedment
Strand Diameter at 0.001 in.
11. Rejection
Diameter Length
[0.025 mm] Slip
11.1 Except as specified in 9.1, coated strand reels repre-
in. mm in. mm in. mm lbf kN
sented by test samples that do not meet the requirements of this
⁄4 (0.250) 6.35 6 152 8.5 216 1700 7.56
specification shall be rejected.
⁄16 (0.313) 7.94 6 152 8.0 203 1960 8.72
⁄8 (0.375) 9.53 6 152 7.5 190 2210 9.83
11.2 A reel of coated strand that is rejected for thickness or
⁄16 (0.438) 11.11 6 152 6.5 165 2230 9.92
continuity of coating shall be accepted if the non-conforming
⁄2 (0.500) 12.70 6 152 6.0 152 2350 10.45
sections are removed and the remaining material meets the
(0.600) 15.25 6 152 5.5 140 2590 11.52
coating requirements of this specification.
12. Certification
concrete reaches a compressive strength between 4000 and
12.1 If outside inspection is waived, a manufacturer’s cer-
5000 psi [30 and 35 MPa], and measured with a calibrated load
tification that the material has been tested in accordance with
indicator at a slip of 0.001 in. [0.025 mm]. A dial gage shall be
and meets the requirements of this specification shall be the
used at the unloaded end to indicate slip. Minimum force at
basis of acceptance of the material. The certification shall
0.001 in. [0.025 mm] slip shall be at least equal to or greater
include the specification number, year-date of issue, and
than the values shown in Table 1.
revision letter, if any.
8. Number of Tests
12.2 The manufacturer shall, when requested in the order,
furnish a representative load-elongation curve for each size and
8.1 Tests for adhesion of coating shall be conducted at the
grade of strand shipped and a copy of the manufacturer’s
end of each manufactured length.
quality control tests.
8.2 Pull-out tests shall be conducted once every 50 000 ft
[15 240 m] of grit-impregnated strand produced.
13. Handling and Identification
9. Retests
13.1 All strapping bands shall be padded or suitable banding
shall be used to prevent damage to the coating. All reels of
9.1 If the specimen for coating thickness, continuity, adhe-
coated strand shall be handled in such a manner as not to
sion of coating, and pull-out tests fail to meet the specified
damage the coating on the strand.
requirements, two retest samples adjacent to the first sample
13.2 Coating damage due to handling shall be repaired in
from the same reel shall be conducted for each failed test. If the
accordance with the recommendation of the manufacturer of
results of both retests meet the specified requirements, the reels
patching material. The repaired coating shall conform to the
represented by the samples shall be accepted.
requirements of Section 7 of this specification.
10. Inspection
13.3 The reel number shall be maintained throughout the
fabrication and coating process to the point of shipment for
10.1 The inspector representing the purchaser shall have
traceability.
free entry while work on the contract of the purchaser is being
performed. The manufacturer shall afford the inspector all
14. Keywords
reasonable facilities to satisfy him that the material is being
furnished in accordance with this specification. All tests and 14.1 coating requirements; corrosion resistance; epoxy coat-
inspection shall be made at the place of manufacture prior to ing; prestressed concrete; steel wire; strand (tendons)
shipment, unless otherwise specified, and shall be conducted so
A 882/A882M
FIG. 1 Recommended Arrangement for Pull-Out Testing
SUPPLEMENTARY REQUIREMENTS
I. EPOXY–COATE
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