ASTM A886/A886M-99
(Specification)Standard Specification for Steel Strand, Indented, Seven-Wire Stress-Relieved for Prestressed Concrete
Standard Specification for Steel Strand, Indented, Seven-Wire Stress-Relieved for Prestressed Concrete
SCOPE
1.1 This specification covers seven-wire uncoated, indented, stress-relieved steel strand for use in pretensioned prestressed concrete construction. Grade 250I and Grade 270I have minimum ultimate strengths of 250 ksi [1725 MPa] and 270 ksi [1860 MPa], respectively, based on the nominal area of the strand.
1.2 Supplement I describes low-relaxation strand and relaxation testing for that product. Low-relaxation strand shall be furnished when specifically ordered, and it may be furnished in place of regular strand if mutually agreed to by the purchaser and supplier.
1.3 This specification is applicable for orders in either inch-pound units (as Specification A886) or in SI units (as Specification A886M).
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standards. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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 886/A 886M – 99
Standard Specification for
Steel Strand, Indented, Seven-Wire Stress-Relieved for
Prestressed Concrete
ThisstandardisissuedunderthefixeddesignationA886/A886M;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 2.3 U.S. Federal Standards:
Fed. Std. No. 123 Marking for Shipments (CivilAgencies)
1.1 Thisspecificationcoversseven-wireuncoated,indented,
stress-relieved steel strand for use in pretensioned prestressed
3. Terminology
concrete construction. Grade 250I and Grade 270I have mini-
3.1 Definitions of Terms Specific to This Standard:
mum ultimate strengths of 250 ksi [1725 MPa] and 270 ksi
3.1.1 strand, n—all strand shall be of the seven-wire type
[1860 MPa], respectively, based on the nominal area of the
having a center wire enclosed tightly by six helically placed
strand.
outerwireswithuniformpitchofnotlessthan12andnotmore
1.2 Supplement I describes low-relaxation strand and relax-
than 16 times the nominal diameter of the strand.
ation testing for that product. Low-relaxation strand shall be
furnished when specifically ordered and furnished in place of
4. Ordering Information
stress-relieved strand if mutually agreed to by the purchaser
4.1 Orders for seven-wire stress-relieved strand under this
and supplier.
specification should include the following information:
1.3 This specification is applicable for orders in either
4.1.1 Quantity (meters [feet]),
inch-pound units (as Specification A886) or in SI units (as
4.1.2 Diameter of strand (millimeters [inches]),
Specification A886M).
4.1.3 Grade of strand,
1.4 The values stated in either inch-pound units or SI units
4.1.4 Packaging,
are to be regarded separately as standards. Within the text, the
4.1.5 ASTM designation and year of issue, and
inch-pound units are shown in parentheses. The values stated
4.1.6 Special requirements, if any.
in each system are not exact equivalents; therefore, each
system must be used independently of the other. Combining
NOTE 1—Atypicalorderingdescriptionisasfollows:25600m(84000
values from the two systems may result in nonconformance ft) 12.70-mm (0.5-in.), Grade 1860I (2701) strand, in 3658-m (12 000-ft)
spoolless packs to ASTM A886/A886M—_______.
with the specification.
5. Materials and Manufacture
2. Referenced Documents
5.1 Base Metal—The base metal shall be carbon steel of
2.1 ASTM Standards:
such quality that when it is drawn to wire, subjected to the
A370 TestMethodsandDefinitionsforMechanicalTesting
indentation process, fabricated into strand, and then stress-
of Steel Products
relieved, it shall have the properties and characteristics pre-
E328 MethodsforStressRelaxationTestsforMaterialsand
scribed in this specification.
Structures
5.2 Wire—The wire from which the strand is to be fabri-
2.2 U.S. Military Standards:
cated shall have a common dry-drawn finish.
MIL-STD-129 Marking for Shipment and Storage
MIL-STD-163 Steel Mill Products Preparation for Ship-
NOTE 2—Thisproductisacompositeofsevenwiresandisproducedto
ment and Storage
mechanical properties only, the chemistry of all wires or any individual
wireisnotpertinenttothisapplication,andheatidentityisnotnecessarily
maintained. It is possible that wire from more than one heat may be used
This specification is under the jurisdiction ofASTM CommitteeA-1 on Steel, inthemanufactureofareelorpack.Traceabilityisbasedonpackidentity
Stainless Steel, and RelatedAlloys and is the direct responsibility of Subcommittee
as maintained and reported by the manufacturer.
A01.05 on Steel Reinforcement.
5.3 Indentations—The outer wires shall have indentations
Current edition approved Sept. 10, 1999. Published December 1999. Originally
published as A886/A886M–88. Last previous edition A886/A886M–98. designed to reduce longitudinal movement of the strand within
Annual Book of ASTM Standards, Vol 01.03.
the concrete, and conform to the provisions in Section7. The
Annual Book of ASTM Standards, Vol 03.01.
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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.
A 886/A 886M – 99
TABLE 2 Breaking Strength Requirements
surface of the outer wires shall be suitably deformed mechani-
cally by rolling to produce a series of indentations. Indenta- Diameter of Strand Mass [Weight]
Steel
Breaking Strength of Strand,
tionsshallbeintwoormorelinesspaceduniformlyaroundthe
Area of Strand,
of Strand, kN (lbf) kg/1000 m
2 2
mm in.
mm (in. )
wire. Indentations in adjacent lines shall be staggered through-
(lb/1000 ft)
out the length of the wire.At least 90% of the indentations in
Grade 1725I [250I]
any 0.6 m (2 ft) length of strand shall meet the pitch and shape
6.4 (0.250) 40.0 (9 000) 23.2 (0.036) 182 (122)
requirements ofTable 1.The center wire need not be indented.
7.9 (0.313) 64.5 (14 500) 37.4 (0.058) 294 (197)
9.5 (0.375) 89.0 (20 000) 51.6 (0.080) 405 (272)
5.4 Stress-Relieving—After stranding, all strand shall be
11.1 (0.438) 120.1 (27 000) 69.7 (0.108) 548 (367)
subjected to a stress-relieving continuous heat treatment to
12.7 (0.500) 160.1 (36 000) 92.9 (0.144) 730 (490)
produce the prescribed mechanical properties. Temper colors
15.2 (0.600) 240.2 (54 000) 139.4 (0.216) 1094 (737)
which result from the stress-relieving operation are considered
Grade 1860I (270I)
normal for the finished appearance of this strand.
7.9 (0.313) 74.3 (16 500) 39.4 (0.061) 313 (210)
9.5 (0.375) 102.3 (23 000) 54.8 (0.085) 432 (290)
6. Mechanical Property Requirements
11.1 (0.438) 137.9 (31 000) 74.2 (0.115) 582 (390)
12.7 (0.500) 183.7 (41 300) 98.7 (0.153) 775 (520)
6.1 Methods of testing for mechanical properties are de-
15.2 (0.600) 266.7 (58 600) 140.0 (0.217) 1102 (740)
scribed in Supplement VII of Methods and Definitions A370.
6.2 Breaking Strength—The breaking strength of the fin-
A
ished strand shall conform to the requirements prescribed in
TABLE 3 Yield Strength Requirements
Table 2.
Diameter of Strand Minimum Load at
Initial Load,
6.3 Yield Strength—Yield strength in kN (lb) is measured 1 % Extension, kN
kN (lbf)
mm (in.)
(lbf)
1% extension under load. The load at this extension shall be
Grade 1725I(250I)
recorded as yield strength and shall meet the requirements
prescribed in Table 3. 6.4 (0.250) 4.0 (900) 34.0 (7 650)
7.9 (0.313) 6.5 (1 450) 54.7 (12 300)
6.3.1 The extension under load shall be measured by an
9.5 (0.375) 8.9 (2 000) 75.6 (17 000)
extensometer calibrated with the smallest division not larger
11.1 (0.438) 12.0 (2 700) 102.3 (23 000)
than 0.0001 mm/mm (0.001 in./in.) of gage length.
12.7 (0.500) 16.0 (3 600) 136.2 (30 600)
15.2 (0.600) 24.0 (5 400) 204.2 (45 900)
6.4 Elongation—The total elongation under load shall be
Grade 1860I(270I)
not less than 3.5% and shall be measured in a gage length of
not less than 600 mm (24 in.). In practice the total elongation 7.9 (0.313) 7.3 (1 650) 62.4 (14 030)
9.5 (0.375) 10.2 (2 300) 87.0 (19 550)
value may be determined by adding to the 1% yield extension
11.1 (0.438) 13.8 (3 100) 117.2 (26 350)
the percent extension or movement between the jaws gripping
12.7 (0.500) 18.4 (4 130) 156.1 (35 000)
the strand after yield determination. The percent is calculated
15.2 (0.600) 26.1 (5 860) 221.5 (49 800)
A
on the new base length of jaw-to-jaw distance.
Yield strength minimum is 85 % of specified minimum breaking strength.
7. Dimensions and Permissible Variations
7.3.3 Variationincross-sectionalareaandinstressresulting
7.1 The size of the finished strand shall be expressed as the
therefromshallnotbecauseforrejectionprovidedthediameter
diameter of the strand in decimals of an inch [millimetre].All
differences of the individual wires and the diameters of the
nominal dimensional requirements for wires and strands shall
strand are within the tolerances specified.
refer to the wire and strand before indenting.
7.4 Indentations:
7.2 The diameter of the center wire of any strand must be
7.4.1 Two acceptable types of indented wire are shown in
larger than the diameter of any outer wire in accordance with
Fig. 1 (a) and ( b) with dimensions given in Table 1.
Table 4.
7.4.2 Other types of indented wire are permitted, by agree-
7.3 Permissible Variations in Diameter:
ment between the purchaser and supplier.
7.3.1 AllGrade250Istrandshallconformtoasizetolerance
8. Workmanship, Finish, and Appearance
of 60.40 mm (60.016 in.) from the nominal diameter mea-
sured across the crowns of the wire. 8.1 Joints:
7.3.2 AllGrade270Istrandshallconformtoasizetolerance 8.1.1 There shall be no strand joints or strand splices in any
of +0.65 mm, −0.15 mm (+0.026 in., −0.006 in.) from the length of the completed strand unless specifically permitted by
nominal diameter measured across the crowns of the wire.
the purchaser.
TABLE 1 Nominal Dimensions of Indentations
Wire Diameter, d Stra
...
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