ASTM A779/A779M-12

Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted 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 covers two types and three grades of compacted, seven-wire, uncoated strand for use in prestressed concrete construction. The two types of strand are low-relaxation and stress-relieved (normal-relaxation). The three grades are 245 [1700], 260 [1800] and 270 [1860].  
1.2 This specification is applicable for orders in either inch-pound units (as Specification A779) or in SI units (as Specification A779M).  
1.3 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the specification.

General Information

• Status: Historical
• Publication Date: 31-Aug-2012
• 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-10 - Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-Relieved for Prestressed Concrete
• Effective Date: 01-Sep-2012
• Replaced By: ASTM A779/A779M-16 - Standard Specification for Steel Strand, Seven-Wire, Uncoated, Compacted for Prestressed Concrete
• Effective Date: 01-Sep-2016

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 −12
StandardSpecification for
Steel Strand, Seven-Wire, Uncoated, Compacted for
1
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. Terminology
1.1 This specification covers two types and three grades of
3.1 Definitions of Terms Specific to This Standard:
compacted, seven-wire, uncoated strand for use in prestressed
3.1.1 compacted strand—strand that has been compacted by
concrete construction. The two types of strand are low-
drawing through a die or a similar compacting process and
relaxation and stress-relieved (normal-relaxation). The three
subsequently stress-relieved prior to winding into reels or
grades are 245 [1700], 260 [1800] and 270 [1860].
reelless packs.
1.2 This specification is applicable for orders in either
3.1.2 lot—all of the compacted strand of the same grade in
inch-pound units (as Specification A779) or in SI units (as
the reels or reelless packs produced on the same production
Specification A779M).
equipment and submitted for inspection at the same time.
1.3 The values stated in either inch-pound or SI units are to
3.1.3 strand—a group of wires having a center wire en-
be regarded as standard.Within the text, the SI units are shown
closed tightly by six helically placed outer wires with a
in brackets. The values stated in each system may not be exact
uniform pitch of not less than 14 and not more than 18 times
equivalents;therefore,eachsystemshallbeusedindependently
the nominal diameter of the strand.
of the other. Combining values from the two systems may
result in non-conformance with the specification.
4. Classification
2. Referenced Documents
4.1 Grade 245 [1700]—Nominal diameter of 0.7 in. [18.0
2
mm] with tensile strength of 247 ksi [1705 MPa] based on
2.1 ASTM Standards:
nominal area of the strand.
A751 Test Methods, Practices, and Terminology for Chemi-
cal Analysis of Steel Products
4.2 Grade 260 [1800]—Nominal diameter of 0.6 in. [15.2
A994 Guide for Editorial Procedures and Form of Product
mm] with tensile strength of 263 ksi [1815 MPa] based on
Specifications for Steel, Stainless Steel, and Related
nominal area of the strand.
Alloys
4.3 Grade 270 [1860]—Nominal diameter of 0.5 in. [12.7
A1061/A1061M Test Methods for Testing Multi-Wire Steel
mm] with tensile strength of 270 ksi [1860 MPa] based on
Strand
3
nominal area of the strand.
2.2 U.S. Military Standard
MIL-STD-129 Marking for Shipment and Storage
3 5. Ordering Information
2.3 U.S. Military Standard
Fed. Std. No. 123 Marking for Shipments (Civil Agencies)
5.1 It shall be the responsibility of the purchaser to specify
all requirements that are necessary for material ordered to this
specification. Such requirements to be considered include, but
1
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
are not limited to, the following:
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
5.1.1 Quantity (feet [metres]),
A01.05 on Steel Reinforcement.
Current edition approved Sept. 1, 2012. Published October 2012. Originally
5.1.2 Type of strand (low-relaxation or stress-relieved
approved in 1980. Last previous edition approved in 2010 as A779/A779M – 10.
(normal-relaxation)),
DOI: 10.1520/A0779_A0779M-12.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 5.1.3 Grade and nominal diameter of strand (Section 4),
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.1.4 Load-elongation curve, if desired (12.2.1),
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.1.5 Outside inspection, if required (Section 13),
3
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
5.1.6 Packaging (16.1), and
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
dodssp.daps.dla.mil. 5.1.7 ASTM designation and date of issue.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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A779/A779M−12
TABLE 1 Breaking Strength Requirements
Nominal Diameter of Strand Specified Minimum Nominal Steel Area of Strand Nominal Mass (Weight) of
Breaking Strength Strands lb/1000 ft [kg/1000 m]
2 2
in. [mm] in. [mm ]
of Strand, lbf [kN]
Grade 270 [1860]
0.5 [12.7] 47 000 [209] 0.174 [112] 600 [890]
Grade 260 [1800]
(0.6 [15.2] 67 440 [300] 0.256 [165] 873 [1295]
Grade 245 [1700]
0.7 [18.0] 8
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A779/A779M − 10 A779/A779M − 12
Standard Specification for
Steel Strand, Seven-Wire, Uncoated, Compacted, Stress-
1
Relieved Compacted for Prestressed Concrete
This standard is issued under the fixed designation A779/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*
1.1 This specification describes covers two types and three grades of compacted, seven-wire, uncoated, stress-relieved uncoated
strand for use in pre-tensioned and post-tensioned prestressed concrete construction. The two types of strand are low-relaxation
and stress-relieved (normal-relaxation). The three grades are 245 [1700], 260 [1800] and 270 [1860].
1.2 Supplement I describes low-relaxation strand and low-relaxation testing. This specification is applicable for orders in either
inch-pound units (as Specification A779) or in SI units (as Specification A779M).
1.3 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, the inch-poundSI units
are shown in parentheses.brackets. The values stated in each system aremay not be exact equivalents; therefore, each system shall
be used independently of the other, without combining values in any way.other. Combining values from the two systems may result
in non-conformance with the specification.
2. Referenced Documents
2
2.1 ASTM Standards:
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A994 Guide for Editorial Procedures and Form of Product Specifications for Steel, Stainless Steel, and Related Alloys
A1061/A1061M Test Methods for Testing Multi-Wire Steel Strand
3
2.2 U.S. Military Standard
MIL-STD-129 Marking for Shipment and Storage
3
2.3 U.S. Federal Standard
Fed. Std. No. 123 Marking for Shipments (Civil Agencies)
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 compacted strand—strand that has been compacted by drawing through a die or a similar compacting process and
subsequently stress-relieved prior to winding into coilsreels or reelless packs.
3.1.2 lot—all of the compacted strand of the same grade and package size in the reels or reelless packs produced on the same
production equipment and submitted for inspection at the same time.
3.1.3 strand—a group of wires having a center wire enclosed tightly by six helically placed outer wires with a uniform pitch
of not less than 14 and not more than 18 times the nominal diameter of the strand.
4. Classification
4.1 Grade 1700 (245)—245 [1700]—Nominal diameter of 18.0 mm (0.7 in.)0.7 in. [18.0 mm] with tensile failure stress of 1705
MPa (247 ksi)strength of 247 ksi [1705 MPa] based on nominal area of the strand.
1
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.05
on Steel Reinforcement.
Current edition approved April 1, 2010Sept. 1, 2012. Published July 2010October 2012. Originally approved in 1980. Last previous edition approved in 20052010 as
A779/A779M – 05.A779/A779M – 10. DOI: 10.1520/A0779_A0779M-10.10.1520/A0779_A0779M-12.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://dodssp.daps.dla.mil.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A779/A779M − 12
4.2 Grade 1800 (260)—260 [1800]—Nominal diameter of 15.2 mm (0.6 in.)0.6 in. [15.2 mm] with tensile failure stress of 1815
MPa (263 ksi)strength of 263 ksi [1815 MPa] based on nominal area of the strand.
4.3 Grade 1860 (270)—270 [1860]—Nominal diameter of 12.7 mm (0.5 in.)0.5 in. [12.7 mm] with tensile failure stress of 1860
MPa (270 ksi)strength of 270 ksi [1860 MPa] based on nominal area of the strand.
5. Ordering Information
5.1 It shall be the responsibility of the purchaser to specify all requirements that are necessary for material ordered to this
...