ASTM A779/A779M-05

Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-Relieved for Prestressed Concrete

ABSTRACT
This specification covers seven-wire, uncoated, compacted, stress-relieved steel strand for prestressed concrete. The chemical requirements, mechanical requirements, and dimensions and permissible variations are presented. The mechanical requirement includes breaking strength, load at 1% extension and elongation. Different test method shall be performed on the strand that includes dimension test, breaking strength test, load at 1% extension test, elongation test and workmanship.
SCOPE
1.1 This specification describes three grades of compacted, seven-wire, uncoated, stress-relieved strand for use in pre-tensioned and post-tensioned prestressed concrete construction.
1.2 Supplement I describes low-relaxation strand and low-relaxation testing.
1.3 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, the inch-pound units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other, without combining values in any way.

General Information

• Status: Historical
• Publication Date: 28-Feb-2005
• 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 A779/A779M-00 - Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-Relieved for Prestressed Concrete
• Effective Date: 01-Mar-2005
• Replaced By: ASTM A779/A779M-10 - Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-Relieved for Prestressed Concrete
• Effective Date: 01-Apr-2010

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: A779/A779M – 05
Standard Specification for
Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-
1
Relieved for Prestressed Concrete
This standard is issued under the fixed designationA779/A779M; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 3.1.3 strand—a group of wires having a center wire en-
closed tightly by six helically placed outer wires with a
1.1 This specification describes three grades of compacted,
uniform pitch of not less than 14 and not more than 18 times
seven-wire, uncoated, stress-relieved strand for use in pre-
the nominal diameter of the strand.
tensioned and post-tensioned prestressed concrete construc-
tion.
4. Classification
1.2 Supplement I describes low-relaxation strand and low-
4.1 Grade 1700 (245)—Nominal diameter of 18.0 mm (0.7
relaxation testing.
in.) with tensile failure stress of 1705 MPa (247 ksi) based on
1.3 The values stated in either inch-pound or SI units are to
nominal area of the strand.
be regarded as standard. Within the text, the inch-pound units
4.2 Grade 1800 (260)—Nominal diameter of 15.2 mm (0.6
are shown in parentheses. The values stated in each system are
in.) with tensile failure stress of 1815 MPa (263 ksi) based on
not exact equivalents; therefore, each system shall be used
nominal area of the strand.
independently of the other, without combining values in any
4.3 Grade 1860 (270)—Nominal diameter of 12.7 mm (0.5
way.
in.) with tensile failure stress of 1860 MPa (270 ksi) based on
2. Referenced Documents nominal area of the strand.
2
2.1 ASTM Standards:
5. Ordering Information
A370 Test Methods and Definitions for Mechanical Testing
5.1 It shall be the responsibility of the purchaser to specify
of Steel Products
all requirements that are necessary for material ordered to this
A751 Test Methods, Practices, andTerminology for Chemi-
specification. Such requirements shall include, but are not
cal Analysis of Steel Products
limited to, the following:
E328 Test Methods for Stress Relaxation for Materials and
5.1.1 Quantity (meters (feet)),
Structures
5.1.2 Grade of strand (Section 4),
3. Terminology 5.1.3 Special inspection requirements, if desired (see Sec-
tion 13),
3.1 Definitions of Terms Specific to This Standard:
5.1.4 Packaging,
3.1.1 compacted strand—strandthathasbeencompactedby
5.1.5 ASTM designation and date of issue, and
drawing through a die or a similar compacting process and
5.1.6 Special requirements, if any.
subsequently stress-relieved prior to winding into coils or
reelless packs.
NOTE 1—Atypical ordering description is as follows: 100 000 m Grade
3.1.2 lot—allofthecompactedstrandofthesamegradeand 260 compacted low-relaxation strand in approximately 3700 m reelless
packs to ASTM A779/A779M (328 000 ft Grade 1800 compacted
package size produced on the same production equipment and
low-relaxation strand in approximately 12 000 ft-reelless packs toASTM
submitted for inspection at the same time.
A779/A779M.)
1 6. Materials and Manufacture
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
6.1 The steel shall be of such quality that, when processed,
A01.05 on Steel Reinforcement.
the finished wire shall be free of detrimental flaws and undue
Current edition approved March 1, 2005. Published March 2005. Originally
segregation.
approved in 1980. Last previous edition approved in 2000 as A779/A779M – 00.
DOI: 10.1520/A0779_A0779M-05.
6.2 Wire from which the strand is to be fabricated shall be
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
in the cold-drawn condition and have a common dry-drawn
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
finish.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
*A Summary of Changes section appears at the end of this standard.
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A779/A779M – 05
TABLE 1 Breaking Strength Requirements
Nominal Diameter of Strand Specified Minimum Nominal Steel Area of Strand Nominal Mass (Weight) of
Breaking Strength Strands kg/1000 m (lb/1000 ft)
2 2
mm (in.) mm (in.)
of Strand, kN (lbf)
Grade 1860 (270)
12.7 (0.5) 209 (47 000) 112 (0.174) 890 (600)
Grade 1800 (260)
15.2 (0.6) 300 (67 440) 165 (0.256) 1295 (873)
Grade 1700 (245)
18.0 (0.7) 380 (85 430) 223 (0.346) 1750 (1176)
TABLE 2 Yield Strength Requirements
6.3 After stranding
...