ASTM A722/A722M-98
(Specification)Standard Specification for Uncoated High-Strength Steel Bar for Prestressing Concrete
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 prestressed concrete construction. 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. The standard sizes and dimensions of Type I and II bars shall be those listed in Tables 1 and 2, respectively.
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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: A 722/A 722M – 98
Standard Specification for
Uncoated High-Strength Steel Bars for Prestressing
Concrete
This standard is issued under the fixed designation A 722/A 722M; 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 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 A 722/
A 722M – ; 26 mm diameter, 12.20 m long, Type II; packed in accordance
surface and Type II bar has surface deformations.
with A 700; 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 The bars shall be rolled from properly identified heats of
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-
A 370 Test Methods and Definitions for Mechanical Testing
ties.
of Steel Products
A 700 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
E 30 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,
5.2 A product analysis may be made by the purchaser from
3.1.5 Type,
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 of ASTM Committee A-1 on Steel,
5.3 Method E 30 shall be used for referee purposes.
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
A01.05 on Steel Reinforcement.
6. Mechanical Properties
Current edition approved April 10, 1998. Published December 1998. Originally
published as A 722 – 75. Last previous edition A 722/A 722M – 97a.
6.1 All testing for mechanical properties shall be performed
Annual Book of ASTM Standards, Vol 01.03.
3 in accordance with the requirements of Methods and Defini-
Annual Book of ASTM Standards, Vol 01.05.
Annual Book of ASTM Standards, Vol 03.05. tions A 370.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
A 722/A 722M – 98
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
A 7.1 Material furnished as Type II bar shall have deforma-
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 The minimum height and minimum projected area of the
15 ⁄8 1.46 0.98 181 0.28
deformations shall conform to the requirements shown in Table
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
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
finished-bar manufacturer to demonstrate that a bar cut at any
Nominal diameters are for identification only. Values have been converted from
metric to inch-pound units.
point along its length may be coupled to any other length of bar
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
shall be provided or designed by the finished-bar manufacturer.
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 The minimum yield strength of Type I and Type II bars
the number of individual deformations and fractional parts of
shall be 85 % and 80 %, respectively, of the minimum ultimate
deformations on any one side of the bar specimen. A measured
tensile strength of the bars. The yield strength shall be
length of the bar specimen shall be considered the distance
determined by either of the methods described in Test Methods
from a point on a deformation to a corresponding point on any
and Definitions A 370; however, in the extension under load
other deformation on the same side of the bar.
method, the total strain shall be 0.7 %, and in the offset method
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. Determinations shall be based on three measurements
in a gage length equal to 20 bar diameters, or 7.0 % in a gage
per deformation: one at the center of the overall length, and the
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
selected following the final processing operation. A
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 3
20 ⁄4 13.3 0.52 1.0 0.04 3.4 0.13
the middle third of the gage length, as indicated by scribe 26 1 17.8 0.70 1.3 0.05 4.4 0.17
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.
46 1 ⁄4 30.1 1.19 2.2 0.09 7.3 0.29
65 2 ⁄2 44.5 1.75 2.9 0.11 9.7 0.38
6.5.2 If the results of an original tension test fail to meet
A
specified requirements, two ad
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.