ASTM A779/A779M-16

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: Published
• Publication Date: 31-Aug-2016
• 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

• Refers: ASTM A994-16 - Standard Guide for Editorial Procedures and Form of Product Specifications for Steel, Stainless Steel, and Related Alloys
• Effective Date: 01-May-2016
• Refers: ASTM A1061/A1061M-20 - Standard Test Methods for Testing Multi-Wire Steel Prestressing Strand
• Effective Date: 01-May-2020

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A779/A779M −16
Standard Specification 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.
3
1. Scope* 2.2 U.S. Military Standard
MIL-STD-129 Marking for Shipment and Storage
1.1 This specification covers two types and three grades of
3
2.3 U.S. Federal Standard
compacted, seven-wire, uncoated strand for use in prestressed
Fed. Std. No. 123 Marking for Shipments (Civil Agencies)
concrete construction. The two types of strand are low-
relaxation and stress-relieved (normal-relaxation). The three
3. Terminology
grades are 245 [1700], 260 [1800], and 270 [1860].
3.1 Definitions of Terms Specific to This Standard:
1.2 This specification is applicable for orders in either
3.1.1 compacted strand—strand that has been compacted by
inch-pound units (as Specification A779) or in SI units (as
drawing through a die or a similar compacting process and
Specification A779M).
subsequently stress-relieved prior to winding into reels or
1.3 The values stated in either inch-pound or SI units are to
reelless packs.
be regarded as standard.Within the text, the SI units are shown
3.1.2 lot—all of the compacted strand of the same grade in
in brackets. The values stated in each system may not be exact
the reels or reelless packs produced on the same production
equivalents;therefore,eachsystemshallbeusedindependently
equipment and submitted for inspection at the same time.
of the other. Combining values from the two systems may
result in non-conformance with the specification. 3.1.3 strand—a group of wires having a center wire en-
closed tightly by six helically placed outer wires with a
1.4 This international standard was developed in accor-
uniform pitch of not less than 14 and not more than 18 times
dance with internationally recognized principles on standard-
the nominal diameter of the strand.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Classification
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.1 Grade 245 [1700]—Nominal diameter of 0.7 in. [18.0
mm] with tensile strength of 247 ksi [1705 MPa] based on
2. Referenced Documents nominal area of the strand.
2
2.1 ASTM Standards: 4.2 Grade 260 [1800]—Nominal diameter of 0.6 in. [15.2
A751 Test Methods, Practices, and Terminology for Chemi- mm] with tensile strength of 263 ksi [1815 MPa] based on
cal Analysis of Steel Products nominal area of the strand.
A994 Guide for Editorial Procedures and Form of Product
4.3 Grade 270 [1860]—Nominal diameter of 0.5 in. [12.7
Specifications for Steel, Stainless Steel, and Related
mm] with tensile strength of 270 ksi [1860 MPa] based on
Alloys
nominal area of the strand.
A1061/A1061M Test Methods for Testing Multi-Wire Steel
Prestressing 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
1
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
specification. Such requirements to be considered include, but
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
are not limited to, the following:
A01.05 on Steel Reinforcement.
Current edition approved Sept. 1, 2016. Published September 2016. Originally
5.1.1 Quantity (feet [metres]),
approved in 1980. Last previous edition approved in 2012 as A779/A779M – 12.
DOI: 10.1520/A0779_A0779M-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Standards volume information, refer to the standard’s Document Summary page on Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
the ASTM website. 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−16
TABLE 1 Breaking Strength Requirements
Specified Minimum
Nominal Diameter of Strand Nominal Steel Area of Strand
Nominal Mass (Weight) of
Breaking Strength
2 2 Strands lb/1000 ft [kg/1000 m]
...

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 − 12 A779/A779M − 16
Standard Specification for
Steel Strand, Seven-Wire, Uncoated, Compacted for
1
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 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.
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 Prestressing 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 reels or reelless packs.
3.1.2 lot—all of the compacted strand of the same grade 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 245 [1700]—Nominal diameter of 0.7 in. [18.0 mm] with tensile strength of 247 ksi [1705 MPa] based on nominal
area of the strand.
4.2 Grade 260 [1800]—Nominal diameter of 0.6 in. [15.2 mm] with tensile strength of 263 ksi [1815 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 Sept. 1, 2012Sept. 1, 2016. Published October 2012September 2016. Originally approved in 1980. Last previous edition approved in 20102012
as A779/A779M – 10.A779/A779M – 12. DOI: 10.1520/A0779_A0779M-12.10.1520/A0779_A0779M-16.
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 − 16
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] 85 430 [380] 0.346 [223] 1176 [1750]
4.3 Grade 270 [1860]—Nominal diameter of 0.5 in. [12.7 mm] with tensile 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
specification
...