ASTM A722/A722M-98(2003)

Standard Specification for Uncoated High-Strength Steel Bar for Prestressing Concrete

SCOPE
1.1 This specification covers uncoated high-strength steel bars intended for use in pretensioned and post-tensioned prestressed concrete construction or in prestressed ground anchors. Bars are of a minimum ultimate tensile strength level of 1035 MPa (150 000 psi).
1.2 Two types of bars are provided: Type I bar has a plain surface and Type II bar has surface deformations.
1.3 Supplementary requirements of an optional nature are provided. They shall apply only when specified by the purchaser.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

General Information

• Status: Historical
• Publication Date: 09-Apr-2003
• ICS: 77.140.15 - Steels for reinforcement of concrete
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.05 - Steel Reinforcement

Relations

• Replaces: ASTM A722/A722M-98 - Standard Specification for Uncoated High-Strength Steel Bar for Prestressing Concrete
• Effective Date: 10-Apr-2003
• Replaced By: ASTM A722/A722M-05 - Standard Specification for Uncoated High-Strength Steel Bar for Prestressing Concrete
• Effective Date: 01-Mar-2005
• Referred By: ASTM C935-19 - Standard Specification for General Requirements for Prestressed Concrete Poles Statically Cast
• Effective Date: 10-Apr-2003
• Referred By: ASTM C1089-19 - Standard Specification for Spun Cast Prestressed Concrete Poles
• Effective Date: 10-Apr-2003
• Referred By: ASTM C1804-20 - Standard Specification for Spun Cast Prestressed Concrete Bases for Tapered Steel Lighting Poles
• Effective Date: 10-Apr-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A 722/A 722M – 98 (Reapproved 2003)
Standard Specification for
Uncoated High-Strength Steel Bars for Prestressing
Concrete
ThisstandardisissuedunderthefixeddesignationA722/A722M;thenumberimmediatelyfollowingthedesignationindicatestheyear
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.6 Special inspection requirements, if desired (see Sec-
tion 12),
1.1 This specification covers uncoated high-strength steel
3.1.7 Special preparation for delivery, if desired (see Sec-
bars intended for use in pretensioned and post-tensioned
tion 11), and
prestressed concrete construction or in prestressed ground
3.1.8 Supplementary requirements, if desired.
anchors. Bars are of a minimum ultimate tensile strength level
of 1035 MPa (150 000 psi).
NOTE 1—A typical ordering description is as follows: 50 uncoated
1.2 Two types of bars are provided: Type I bar has a plain high-strength steel bars for prestressing concrete to ASTM A722/
A722M–__; 26 mm diameter, 12.20 m long, Type II; packed in
surface and Type II bar has surface deformations.
accordance with A700; meeting supplementary bending properties.
1.3 Supplementary requirements of an optional nature are
provided. They shall apply only when specified by the pur-
4. Materials and Manufacture
chaser.
4.1 Thebarsshallberolledfromproperlyidentifiedheatsof
1.4 The values stated in SI units are to be regarded as the
ingot cast or strand cast steel. The standard sizes and dimen-
standard. The values given in parentheses are for information
sions of Type I and II bars shall be those listed in Table 1 and
only.
Table 2, respectively.
2. Referenced Documents 4.2 The bars shall be subjected to cold-stressing to not less
than 80% of the minimum ultimate strength, and then shall be
2.1 ASTM Standards:
stress relieved, to produce the prescribed mechanical proper-
A370 TestMethodsandDefinitionsforMechanicalTesting
ties.
of Steel Products
A700 Practices for Packaging, Marking, and Loading
5. Chemical Composition
Methods for Steel Products for Domestic Shipment
5.1 An analysis of each heat of steel shall be made by the
E30 Test Methods for Chemical Analysis of Steel, Cast
4 manufacturer from test samples taken during the pouring of
Iron, Open-Hearth Iron, and Wrought Iron
each heat.
3. Ordering Information 5.1.1 Choice and use of chemical composition and alloying
elements, to produce the mechanical properties of the finished
3.1 Orders for material under this specification should
bar prescribed in 6.2, shall be made by the manufacturer,
include the following information:
subject to the limitations in 5.1.2.
3.1.1 Quantity,
5.1.2 On heat analysis, phosphorus and sulfur shall not
3.1.2 Name of material (uncoated high-strength bars for
exceed the following:
prestressing concrete),
Phosphorus 0.040 %
3.1.3 ASTM designation and year of issue,
Sulfur 0.050 %
3.1.4 Size and length,
3.1.5 Type, 5.2 Aproduct analysis may be made by the purchaser from
the finished bar representing each cast or heat of steel. The
phosphorus and sulfur contents thus determined shall not
exceed the limits specified in 5.1.2 by 0.008%.
This specification is under the jurisdiction ofASTM CommitteeA01 on Steel,
5.3 Test Methods E30 shall be used for referee purposes.
Stainless Steel, and RelatedAlloys and is the direct responsibility of Subcommittee
A01.05 on Steel Reinforcement.
6. Mechanical Properties
Current edition approved April 10, 2003. Published July 2003. Originally
approved in 1975. Last previous edition approved in 1998 as A722/A722M – 98.
6.1 All testing for mechanical properties shall be performed
Annual Book of ASTM Standards, Vol 01.03.
in accordance with the requirements of Test Methods and
Annual Book of ASTM Standards, Vol 01.05.
Discontinued. See 1994 Annual Book of ASTM Standards, Vol 03.05. Definitions A370.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 722/A 722M – 98 (2003)
TABLE 1 Dimensions for Type I (Plain) Bar
6.5.3 If any test specimen fails because of mechanical
A
Nominal Diameter Nominal Mass (Weight) Nominal Area reasons such as failure of testing equipment, it shall be
2 2
discarded and another specimen taken.
mm in. kg/m lb/ft mm in.
6.5.4 If any test specimen develops flaws, it shall be
19 ⁄4 2.23 1.50 284 0.44
22 ⁄8 3.04 2.04 387 0.60 discarded and another specimen of the same size bar from the
25 1 3.97 2.67 503 0.78
same heat substituted.
29 1 ⁄8 5.03 3.38 639 0.99
32 1 ⁄4 6.21 4.17 794 1.23
7. Requirements for Deformations
35 1 ⁄8 7.52 5.05 955 1.48
7.1 Material furnished as Type II bar shall have deforma-
A
The nominal area is determined from the nominal diameter in inches. Values
tions spaced uniformly along the length of the bar. The
have been converted from inch-pound units to metric units.
deformations on opposite sides of the bar shall be similar in
size and shape. The average spacing or distance between
TABLE 2 Dimensions for Type II (Deformed) Bar
A B
deformations on both sides of the bar shall not exceed seven
Nominal Diameter Nominal Mass (Weight) Nominal Area
tenths of the nominal diameter of the bar.
2 2
mm in. kg/m lb/ft mm in.
7.2 Theminimumheightandminimumprojectedareaofthe
15 ⁄8 1.46 0.98 181 0.28
deformationsshallconformtotherequirementsshowninTable
20 ⁄4 2.22 1.49 271 0.42
26 1 4.48 3.01 548 0.85
3.
32 1 ⁄4 6.54 4.39 806 1.25
7.3 Mechanical Coupling—For those bars having deforma-
36 1 ⁄8 8.28 5.56 1019 1.58
3 tions arranged in a manner to permit coupling of the bars with
46 1 ⁄4 13.54 9.10 1664 2.58
65 2 ⁄2 27.10 18.20 3331 5.16 a screw-on type coupler, it shall be the responsibility of the
A
Nominaldiametersareforidentificationonly.Valueshavebeenconvertedfrom finished-bar manufacturer to demonstrate that a bar cut at any
metric to inch-pound units.
pointalongitslengthmaybecoupledtoanyotherlengthofbar
B
The nominal area is determined from the bar weight less 3.5 % for the
and that a coupled joint supports the minimum specified
ineffective weight of the deformations.
ultimate tensile strength of the coupled bars. The coupler type
shallbeprovidedordesignedbythefinished-barmanufacturer.
6.2 Tensile Properties:
8. Measurements of Deformations
6.2.1 Finished bars shall have a minimum ultimate tensile
8.1 The average spacing of deformations shall be deter-
strength of 1035 MPa (150 000 psi).
mined by dividing a measured length of the bar specimen by
6.2.2 TheminimumyieldstrengthofTypeIandTypeIIbars
the number of individual deformations and fractional parts of
shallbe85%and80%,respectively,oftheminimumultimate
deformations on any one side of the bar specimen.Ameasured
tensile strength of the bars. The yield strength shall be
length of the bar specimen shall be considered the distance
determinedbyeitherofthemethodsdescribedinTestMethods
from a point on a deformation to a corresponding point on any
and Definitions A370; however, in the extension under load
other deformation on the same side of the bar.
method,thetotalstrainshallbe0.7%,andintheoffsetmethod
8.2 The average height of deformations shall be determined
the offset shall be 0.2%.
from measurements made on not less than two typical defor-
6.2.3 The minimum elongation after rupture shall be 4.0%
mations.Determinationsshallbebasedonthreemeasurements
in a gage length equal to 20 bar diameters, or 7.0% in a gage
perdeformation:oneatthecenteroftheoveralllength,andthe
length equal to 10 bar diameters.
other two at the quarter points of the overall length.
6.3 Test Specimens—Tension tests shall be made using
8.3 To indicate adequately the conformity to the dimen-
full-size bar test specimens. Machined reduced section test
sional requirements, measurements shall be taken at random
specimens are not permitted. All unit stress determinations
from one bar from each 30 Mg (33 tons) of each lot or fraction
shall be based on the nominal area shown in Table 1 or the
thereof.
effective area shown in Table 2.
6.4 Number of Tests—The number of tensile specimens
TABLE 3 Deformation Dimensions for Type II Bar
tested shall be one from each 36 Mg (39 tons) or fraction
Deformation Dimensions
thereof, of each size of bar rolled from each heat but not less
Nominal
Maximum Minimum Minimum
than two from each heat. The specimens shall be randomly
Diameter
Average Average Projected
A
selected following the final processing operation.
Spacing Height Area
6.5 Retests:
2 2
mm in. mm in. mm in. mm /mm in. /in.
6.5.1 If any tensile property of any tension test specimen is
15 ⁄8 11.1 0.44 0.7 0.03 2.4 0.09
less than that specified, and any part of the fracture is outside
20 ⁄4 13.3 0.52 1.0 0.04 3.4 0.13
26 1 17.8 0.70 1.3 0.05 4.4 0.17
the middle third of the gage length, as indicated by scribe
32 1 ⁄4 22.5 0.89 1.6 0.06 5.4 0.21
scratches marked on the specimen before testing, a retest shall
36 1 ⁄8 25.1 0.99 1.8 0.07 6.1 0.24
be allowed. 3
46 1 ⁄4 30.1 1.19 2.2 0.09 7.3 0.29
65 2 ⁄2 44.
...