report on steel reinforcement— material properties and u.s. … · 2020. 5. 12. · the material...

ACI 439.4R-09

Reported by ACI Committee 439

Report on Steel Reinforcement—Material Properties and

U.S. Availability

Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=University of Texas Revised Sub Account/5620001114, User=wer, weqwe

Not for Resale, 01/26/2015 02:03:15 MSTNo reproduction or networking permitted without license from IHS

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Report on Steel Reinforcement—Material Properties and U.S. Availability

First PrintingOctober 2009

ISBN 978-0-87031-348-6

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ACI 439.4R-09 supersedes ACI 439.4R-89 and was adopted and published October2009.

Copyright © 2009, American Concrete Institute.All rights reserved including rights of reproduction and use in any form or by any

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439.4R-1

ACI Committee Reports, Guides, Manuals, and Commentariesare intended for guidance in planning, designing, executing,and inspecting construction. This document is intended for theuse of individuals who are competent to evaluate thesignificance and limitations of its content and recommendationsand who will accept responsibility for the application of thematerial it contains. The American Concrete Institute disclaimsany and all responsibility for the stated principles. The Instituteshall not be liable for any loss or damage arising therefrom.

Reference to this document shall not be made in contractdocuments. If items found in this document are desired by theArchitect/Engineer to be a part of the contract documents, theyshall be restated in mandatory language for incorporation bythe Architect/Engineer.


Reported by ACI Committee 439

ACI 439.4R-09

The material properties of the various types of steel reinforcementproduced for use in the United States are described. Types of steel reinforce-ment defined in this report include deformed reinforcing bars, plain anddeformed wire, welded wire reinforcement, bar mats, and prestressingreinforcement. The requirements, restrictions, and testing information ofthe pertinent ASTM specifications are reviewed. The availability of thevarious types and sizes of reinforcement in the U. S. is discussed.

Keywords: bend tests; bending (reinforcing steels); deformed reinforcement;deformed reinforcing bars; ductility; material properties; prestressingsteels; reinforced concrete; reinforcing steels; specifications; spiralreinforcement; tensile strength; welded reinforcement grids; welded wirefabric; welded wire reinforcement; yield strength.

CONTENTSChapter 1—Introduction and scope, p. 439.4R-2

1.1—Introduction1.2—Scope

Chapter 2—Notation and definitions, p. 439.4R-22.1—Notation2.2—Definitions

Chapter 3—Reinforcing bars, p. 439.4R-23.1—Introduction3.2—Material properties3.3—Availability3.4—Welding3.5—Material testing3.6—Spirals and mats3.7—Corrosion protection products

Joseph A. Bohinsky Paul S. Fredrickson Peter Meza Mario A. Rodriguez

Domingo J. Carreira* Todd R. Hawkinson Theodore A. Mize* Philip E. Ross

Augusta Carroll Steven H. Holdsworth Conrad Paulson Clifford A. Sabo

Louis J. Colarusso Allen J. Hulshizer Ryan W. Pelter Robert G. Smith

David H. DeValve Harry B. Lancelot, III Richard A. Ramsey Dyke W. Starnes

Gustav G. Erlemann† Kenneth A. Luttrell Roy H. Reiterman Kenneth W. Williamson

Salem S. Faza LeRoy A. Lutz* Robert C. Richardson William H. Zehrt, Jr.

Anthony L. Felder* A. Murray Lount†

*Subcommittee members who produced this report.†Deceased.

Mark. D. MarvinChair

William C. GallenzSecretary



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439.4R-2 ACI COMMITTEE REPORT

Chapter 4—Plain and deformed wire, p. 439.4R-104.1—Introduction4.2—Material properties4.3—Wire size designation4.4—Availability4.5—Corrosion protection products

Chapter 5—Welded wire reinforcement,p. 439.4R-11

5.1—Introduction5.2—Material properties5.3—Higher-strength welded wire reinforcement5.4—Welded wire reinforcement styles5.5—Availability5.6—Minimum quantity requirements5.7—Corrosion protection products

Chapter 6—Prestressing reinforcement,p. 439.4R-13

6.1—Introduction6.2—Material properties6.3—Availability6.4—Corrosion protection products6.5—Other prestressing reinforcement

Chapter 7—Developments in reinforcing steel,p. 439.4R-17

7.1—High relative rib area reinforcing bars7.2—Low-carbon, chromium steel reinforcing bars

Chapter 8—References, p. 439.4R-188.1—Referenced standards and reports8.2—Cited references

CHAPTER 1—INTRODUCTION AND SCOPE1.1—Introduction

The material properties of the various types of steelreinforcement produced for use in the U.S. are described.Types of steel reinforcement defined in this report includedeformed reinforcing bars, plain and deformed wire, weldedwire reinforcement, bar mats, and prestressing reinforcement.The requirements, restrictions, and testing information ofpertinent ASTM specifications are reviewed. The availabilityof the various types and sizes of reinforcement in the U.S.is discussed.

1.2—ScopeRequirements for reinforcement are stated in Section 3.5.1

of ACI 318-08 as: “Reinforcement shall be deformed reinforce-ment, except that plain reinforcement shall be permittedfor spirals or prestressing steel...” Deformed reinforcementis defined in Section 2.2 of ACI 318-08 as: “Deformedreinforcing bars, bar mats, deformed wire, welded wirereinforcement conforming to Section 3.5.3.” This reportexcludes discussion of structural steel, steel pipe, steeltubing, steel fibers, expanded metal, and fiber-reinforcedpolymers (FRP) and other nonmetallic reinforcement.

This report describes these types of steel reinforcement interms of availability and material properties, expressed ininch-pound units and metric units. The special requirements

of ACI 349 and 359 are also discussed. American Associa-tion of State Highway and Transportation Officials(AASHTO) requirements (2002, 2004) are not discussed inthis report because they generally follow ACI 318.

CHAPTER 2—NOTATION AND DEFINITIONS2.1—Notation

There is no notation used in this document.

2.2—Definitionscompacted strand—prestressing strand that is drawn

through a circular die deforming the wires to produce astrand with a smaller circular shape.

indented strand—prestressing strand in which the outerwires have small indentations to permit more rapid transferof strand force to the concrete.

See ACI CT, ‘Concrete Terminology,’ for definitions atthe ACI Web site, http://www.concrete.org/Technical/CCT/FlashHelp/ACI_Terminology.htm.

CHAPTER 3—REINFORCING BARS3.1—Introduction

Reinforcing bars are the most popular type of nonprestressedreinforcing steel used in concrete construction. Approximately10 million tons of reinforcing bars are used in the U.S.every year. Nearly all reinforced concrete construction,including precast and prestressed structures, requires somereinforcing bars.

Most of the reinforcing bars used in construction aredeformed bars; that is, the bars have deformations to enhancethe bond of the steel to the surrounding concrete. Limits onthe deformation dimensions, such as the minimum deformationheight and maximum deformation spacing, are prescribed inASTM specifications. Plain reinforcing bars, which do nothave deformations, are only permitted by ACI 318 for spiralreinforcement as used in reinforced concrete columns.

3.2—Material propertiesThe mechanical property requirements, chemical composi-

tion restrictions, and other requirements of the ASTM spec-ifications for reinforcing bars are summarized in Tables3.1 through 3.3. Reinforcing bars are primarily a hot-rolledproduct. The bars are manufactured by a steel mill usingelectric-arc furnaces to melt scrap steel to produce billets.These billets are then heated and passed through a series ofrolls to make reinforcing bars. The deformations are formedon the bars during the final pass through the rolls.

Most of the properties of reinforcing bars of interest to theArchitect/Engineer are defined by ASTM specifications.The significance of certain properties as defined by ASTM,however, is not readily apparent, and some special propertiesrelated to structural design are not defined by ASTM. Therefore,a brief review of the significance of various mechanicalproperties on structural design is appropriate. Plots of idealizedstress-strain curves for ASTM A615 and ASTM A706reinforcing bars are shown for two strain ranges in Fig. 3.1.

Of prime importance in structural design is the yieldstrength of nonprestressed reinforcement. ACI 318 requiresdetermination of yield strengths over 60 ksi (420 MPa) at a



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REPORT ON STEEL REINFORCEMENT—MATERIAL PROPERTIES AND U.S. AVAILABILITY 439.4R-3

Table 3.1—Summary of minimum ASTM strength requirements for reinforcing steel

MaterialASTM

specification Grade designationMinimum yield strength,

psi (MPa)Minimum tensile strength,

psi (MPa)

Reinforcing barsA615/A615M

Grade 40 (280)Grade 60 (420)Grade 75 (520)

40,000 (280)60,000 (420)75,000 (520)

60,000 (420)90,000 (620)

100,000 (690)

A706/A706M Grade 60 (420) 60,000 (420)[78,000 (540) maximum] 80,000 (550)*

Stainless steel reinforcing bars A955/A955MGrade 40 (300)Grade 60 (420)Grade 75 (520)

40,000 (300)60,000 (420)75,000 (520)

70,000 (500)90,000 (620)

100,000 (690)

Low-carbon chromiumsteel reinforcing bars A1035/A1035M Grade 100 (690)

Grade 120 (830)100,000 (690)120,000 (830)

150,000 (1030)150,000 (1030)

Deformed bar mats A184/A184M Same as reinforcing bars

Zinc-coated (galvanized) bars A767/A767M Same as reinforcing bars

Epoxy-coated bars A775/A775MA934/A934M Same as reinforcing bars

Wire—plain A82/A82M 70,000 (485) 80,000 (550)

Wire—deformed A496/A496M 75,000 (515) 85,000 (585)

Welded wire Plain (W1.2 (MW8) and larger) (smaller than W1.2 (MW8))

A185/A185M 65,000 (450)

56,000 (385)

75,000 (515)

70,000 (485)

Deformed A497/A497M 70,000 (485) 80,000 (550)

Epoxy-coated wire/welded wire A884/A884M Same as wire or welded wire

Stainless steel wire/welded wire A1022/A1022M Same as wire or welded wire

Seven-wire strand for prestressing A416/A416M

Grade 250 (stress-relieved) 212,500 (1465) 250,000 (1725)

Grade 250 (low-relaxation) 225,000 (1555) 250,000 (1725)



Wire for prestressing A421/A421MStress-relieved 199,750 to 212,500 (1377 to 1465)† 235,000 to 250,000 (1620 to 1725)†

Low-relaxation 211,500 to 225,000 (1460 to 1550)† 235,000 to 250,000 (1620 to 1725)†

Bars for prestressing A722/A722MType I (plain) 127,500 (880) 150,000 (1035)

Type II (deformed) 120,000 (830) 150,000 (1035)

Compacted strand for prestressing‡ A779/A779M







Epoxy-coated seven-wire strand for prestressing‡ A882/A882M Same as seven-wire strand

Seven-wire indented strand for prestressing‡ A886/A886M

Grade 250I (1725I)(stress-relieved) 212,500 (1465) 250,000 (1725)

Grade 250I (1725I)(low-relaxation) 225,000 (1550) 250,000 (1725)

Grade 270I (1860I)(stress-relieved) 229,500 (1580) 270,000 (1860)

Grade 270I (1860I)(low-relaxation) 243,000 (1675) 270,000 (1860)

Two- and three-wire strand for prestressing A910/A910M

Grade 250(stress-relieved) 212,500 (1465) 250,000 (1725)

Grade 250(low-relaxation) 225,000 (1550) 250,000 (1725)

Grade 270(stress-relieved) 229,500 (1580) 270,000 (1860)

Grade 270(low-relaxation) 243,000 (1675) 270,000 (1860)

*But not less than 1.25 times the actual yield strength.†Minimum strength depends on wire sizes and type.‡Not listed in ACI 318.



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Table 3.2—ASTM mechanical property requirements for reinforcing bars

Type of steel and ASTM designation

Gradedesignation

Minimum yield strength, psi (MPa)*

Minimum tensile strength, psi (MPa)

Range of bar size designation†

Minimum percentage of elon-gation in 8 in. (203.2 mm)

Pin diameter for bend test‡

(db = nominal diameter of bar)

Carbon,A615/A615M

40 (280) 40,000 (280) 60,000 (420)

3 (10) 113-1/2db 4 (13)

125 (16)

6 (19) 5db

60 (420) 60,000 (420) 90,000 (620)

3 (10)

93-1/2db4 (13)

5 (16)6 (19)

5db7 (22)8

8 (25)9 (29)

7

7db10 (32)11 (36)14 (43) (90 degrees)

9db18 (57)

75 (520) 75,000 (520) 100,000 (690)

6 (19)7 5db7 (22)

8 (25)9 (29)

6

7db10 (32)11 (36)14 (43) (90 degrees)

9db18 (57)

Low-alloy,A706/A706M 60 (420)

60,000 minimum (420)

78,000 maximum (540)

80,000§ (550)

3 (10)

143db4 (13)

5 (16)6 (19)

4db7 (22)

128 (25)9 (29)

6db10 (32)11 (36)14 (43)

10 8db18 (57)

Stainless,A955/A955M

40 (300) 40,000 (300) 70,000 (500)

3 (10)

203-1/2db4 (13)

5 (16)

6 (19) 5db

60 (420) 60,000 (420) 90,000 (620)

3 (10)

20

3-1/2db4 (13)5 (16)6 (19)

5db7 (22)8 (25)9 (29)

7db10 (32)11 (36)14 (43) (90 degrees)

9db18 (57)

75 (520) 75,000 (520) 100,000 (690)

6 (19)

20

5db7 (22)8 (25)9 (29)

7db10 (32)11 (36)14 (43) (90 degrees)

9db18 (57)



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stress that corresponds to a strain of 0.35% and limits yieldstrength used in design to a maximum of 80 ksi (550 MPa).An exception to this maximum is made for transverse spiralsthat can be used to a maximum of 100 ksi (690 MPa). Thepurpose of these requirements is to provide for reliable appli-cation of the strength design approach. ASTM specificationsrequire that the yield strength be determined at a prescribedstrain when the steel does not have a well-defined yieldpoint. Variability in mechanical properties was investigatedby Mirza and MacGregor (1979). For information on bendtests, see Kudder and Gustafson (1983).

3.2.1 Ductility—Tensile-test ductility requirements (after-fracture measurement of the elongation of a tensile specimen)as specified by ASTM resulted in the production of reinforcingbars that have generally experienced very few fracturesduring fabrication or in service in reinforced concretestructures, even in the case of structures subjected to seismic,blast, or wind forces. It is important in any inelastic analysisto realize that useful ductility is limited to the strain corre-sponding to the maximum stress on the stress-strain curve,and this may be less than half the ultimate ductility. Inaddition, the ductility may be reduced if the reinforcementbuckles under load reversals.

Ductility of reinforcing bars is not an important parameterin reinforced concrete members subjected primarily tocompression, but ductility is important in slabs and beams orin columns with significant bending or axial tension. Anexample would be a structure subjected to seismic, blast, orwind forces where the percentage of reinforcing steel is lowand there is a possibility of steel rupture before concretecrushing (McDermott 1998). Rupture of longitudinal steelhas generally been precluded in flexural members by usingsteels with ductility as defined by ASTM and by imposing

Low-carbonchromium,

A1035/A1035M

100 (690)

100,000 (690)

80,000 (550)at 0.35% strain

150,000 (1030)

3 (10)

7

3-1/2db4 (13)5 (16)6 (19)

5db7 (22)8 (25)9 (29)

7db10 (32)11 (36)14 (43)

6(90 degrees)

9db18 (57)

120 (830)

120,000 (830)

90,000 (620)at 0.35% strain

150,000 (1030)

3 (10)

7

3-1/2db4 (13)5 (16)6 (19)

5db7 (22)8 (25)9 (29)

7db10 (32)11 (36)14 (43)

6(90 degrees)

9db18 (57)*Yield point or yield strength; refer to ASTM specifications.†Bar numbers are based on the number of eighths of an inch included in the nominal diameter of the bars (bar numbers approximate the number of millimeters of the nominal diameterof the bar).‡Test bends over 180 degrees unless noted otherwise.§Tensile strength should not be less than 1.25 times the actual yield strength.

Table 3.2—ASTM mechanical property requirements for reinforcing bars (cont.)

Fig. 3.1—Idealized stress-strain curves for reinforcing bars.Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=University of Texas Revised Sub Account/5620001114, User=wer, weqwe


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lower limits on steel percentage, such as given in Section 10.5of ACI 318-08 (McDermott 1974). Ductility is important inmembers subjected to membrane tension, as in some structuralcomponents, such as shearwalls or diaphragms that may besubjected to seismic, blast, or wind forces.

3.2.2 Properties not defined by ASTM—ASTM specificationsfor reinforcing bars do not include restrictions regardingstrength under fatigue or impact properties when loadingintroduces high strain rates. Reinforcing bars are not subjectto fatigue or impact failures in most structures. Refer toHelgason and Hansen (1974) for information on fatiguestrength of reinforcing bars. No practical methods for testing

impact properties of reinforcing bars have been devised;Charpy tests (ASTM D5942, withdrawn 1998) on machinedspecimens do not reflect impact properties of a deformedbar. High strain rates result in higher yield strengths and, toa lesser extent, higher tensile strengths. Ductility is generallynot sensitive to the strain rate (Cowell 1965; Siess 1962;Crum 1959; McDermott 1974; Malvar 1998; Malvar andCrawford 1998).

3.3—AvailabilityReinforcing bars that conform to ASTM A615/A615M for

carbon steel (previously called billet-steel) are the mostcommonly produced and specified type. The vast majority of

Table 3.3—Reinforcing bars: ASTM chemical composition restrictions and other requirementsASTM

specification Chemical composition restrictions Other requirements

A615/A615M

0.06% maximum phosphorus (heat)0.075% maximum phosphorus (finished bar)

Tensile retests permitted on two random specimens when:a) Yield strength of original specimen is within 1000 psi (7 MPa) ofspecification minimum;b) Tensile strength of original specimen is within 2000 psi (14 MPa) ofspecification minimum; orc) Elongation of original specimen is within two percentage units ofspecification minimum.Bend retests permitted on two random specimens.

Bar mark for type of steel: S

A706/A706M

Chemical composition limited to:

Same retest provisions as described previously for A615/A615M.

The manufacturer should report the chemical composition and carbonequivalent for each heat of steel to the purchaser or his representative.

Bar mark for type of steel: W

(“S” and “W” for bars meeting both A615/A615M and A706/A706M)

ElementMaximum%

(heat)Maximum %(finished bar)

Carbon 0.30 0.33

Manganese 1.50 1.56

Phosphorus 0.035 0.043

Sulfur 0.045 0.053

Silicon 0.50 0.55

Carbon equivalent (C.E.) limited to 0.55% calculated by

C.E. = %C + + + + – –

A955/A955M

Chemical composition, %

Same retest provisions as described previously for A615/A615M.

In addition, report:1) Heat treat condition;2) Magnetic permeability (if appropriate);3) Hardness (if appropriate); and4) Corrosion test (if appropriate).

UNSdesignation S24000 S24100 S30400 S31603 S31653 S31803

Type XM-29 XM-28 304 316L 316LN ....

Carbon 0.08 0.15 0.08 0.03 0.08 0.03

Manganese 11.50-14.50

11.00-14.00 2.00 2.00 2.00 2.00

Phosphorus 0.060 0.060 0.045 0.045 0.045 0.045

Sulfur 0.030 0.030 0.030 0.030 0.030 0.020

Silicon 1.0 1.0 1.0 1.0 1.0 1.0

Chromium 17.00-19.00

16.50-19.00

18.00-20.00

16.00-18.00

16.00-18.00

21.00-23.00

Nickel 2.25-3.75

0.50-2.50

8.00-10.50

10.00-14.00

10.00-14.00

4.50-6.50

Molybdenum .... .... .... 2.00-3.00

2.00-3.00

2.50-3.50

Nitrogen 0.20-0.40

0.20-0.45 0.10 0.10 0.10-

0.160.08-0.20

A1035/ A1035M

Chemical composition limited to:

Same retest provisions as described previously for A615/A615M

Bar mark for type of steel: CS

ElementCarbonChromiumManganeseNitrogenPhosphorusSulfurSilicon

Maximum %0.158.0 to 10.91.50.050.0350.0450.50

%Mn6

------------- %Cu40

------------ %Ni20

----------- %Cr10

----------- %Mo50

------------- %V10

---------



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construction uses carbon-steel bars. Carbon-steel bars arereadily available throughout the U.S. Most of the producersroll reinforcing bars in 60 ft (18 m) stock lengths. Obtaininglengths longer than 60 ft (18 m) normally requires makingspecial arrangements with the supplier having that capability.Alternatively, longer lengths can be obtained by using mechan-ical splices that develop the full strength of the reinforcing bars.

Reinforcing bars are typically furnished as shop-fabricated toa construction project. Shop fabrication means the bars havebeen cut to lengths, bent, bundled, and tagged for identification.Companies that furnish shop-fabricated reinforcing bars arecommonly called fabricators. Reinforcing bars are fabricatedfrom information developed by the fabricator from theproject drawings. Fabricators obtain stock-length and coiledreinforcing bars directly from steel mills.

In 1997, steel mills that produced reinforcing bars beganto phase in the production of bars conforming to soft metricsizes. Within a few years, the shift to exclusive production ofsoft metric reinforcing bars was essentially achieved. Virtuallyall reinforcing bars currently produced in the U.S. are softmetric. Soft metric conversion enables the industry tofurnish the same reinforcing bars to inch-pound and metricconstruction projects, eliminating the need for the steel millsand fabricators to maintain a dual inventory. The sizes of softmetric reinforcing bars are physically the same as the corre-sponding sizes of inch-pound bars. Soft metric bar sizes,which are designated No. 10, No. 13, No. 16, and so on,correspond to inch-pound bar sizes No. 3, No. 4, No. 5, andso on. The metric bar designations are simply a relabeling ofthe inch-pound bar designations. Table 3.2 shows the one-to-one correspondence of the soft metric bar designationnumbers to the inch-pound bar designation numbers.

Producers may require orders in large quantities—usuallyheat lots—to roll lengths over 60 ft (18 m). Stock material in20, 30, and 40 ft (6, 9, and 12 m) lengths is normally available,usually in the smaller bar sizes (No. 3 through No. 6 [No. 10through No. 19]). Stock material in Grade 60 (420) for No. 3and No. 4 (No. 10 and No. 13) bars is available in 1500 and3000 lb (700 and 1400 kg) coils (approximate weight or mass).Coil stock is commonly used by fabricators with automaticbending equipment for the fabrication of ties and stirrups.Coils of reinforcing bars in sizes No. 3 through No. 5 (No. 10through No. 16) are also used by fabricators that specializein fabricating spirals.

In general, ASTM A615/A615M Grade 40 (280)(minimum specified yield strength = 40,000 psi [280 MPa])in bar sizes No. 3 through No. 6 (No. 10 through No. 19) andGrade 60 (420) (minimum specified yield strength = 60,000 psi[420 MPa]) in bar sizes No. 3 through No. 11 (No. 10through No. 36) are readily available in lengths up to 60 ft(18 m) in all parts of the country. Grade 60 (420) in bar sizesNo. 14 and No. 18 (No. 43 and No. 57) is generally available, butthese bar sizes are not usually kept in a fabricator’s inventory.

ASTM A615/A615M also includes provisions for Grade 75(520) in bar sizes No. 6 through No. 11 (No. 19 through No. 36),No. 14 (No. 43), and No. 18 (No. 57). The minimum yieldstrength-strain requirement in A615/A615M is compatiblewith ACI 318; that is, the Grade 75 (520) minimum yield

strength of 75,000 psi (520 MPa) corresponds to a strain of0.35%. Typically, Grade 75 (520) reinforcing bars are used incolumns made with high-strength concrete.

ASTM A706/A706M for low-alloy steel reinforcing barswas issued in 1974 to meet specific needs for controlledtensile properties for seismic-resistant design and construction,and controlled chemical composition for weldability(Gustafson and Felder 1991). During the 20 years followingissuance of ASTM A706/A706M, the demand, and conse-quently, the availability, of A706/A706M bars was notclearly defined. A trend appears to have started towardincreased and exclusive use of low-alloy steel reinforcingbars. In 1995, for example, the California Department ofTransportation (Caltrans) revised its Standard Specifications(Caltrans 1995) to require low-alloy steel reinforcing bars toconform to ASTM A706/A706M for virtually all reinforcedconcrete structures. The only exceptions to the revisedrequirements issued by Caltrans that allow the use of carbon-steel bars that conform to ASTM A615/A615M are slopeand channel paving, certain types of concrete barriers, andtemporary railing. Several other public agencies within theState of California have followed the lead of Caltrans byrequiring low-alloy steel bars for construction projects. In1996, the Nevada Department of Transportation imple-mented a policy that requires A706/A706M bars in theconstruction of essentially all reinforced concrete structures.The Illinois Department of Transportation followed suit in2005 by permitting only A706/A706M bars for all reinforcedconcrete structures. Usage of low-alloy reinforcing bars hasalso increased in other sectors, such as other governmentagencies and privately-financed building construction.

Rail-steel and axle-steel reinforcing bars are covered byASTM A996/A996M. Because rail-steel and axle-steel barsare only available in a few areas of the country, these typesof bars are not discussed in detail herein. Requirements foruse of rail-steel or axle-steel bars may be found in ASTMA996/A996M and in Section 3.5.3 of ACI 318-08.

Reinforcing bars with special chemical or physical propertiesmay be produced for particular applications, such as nuclearpower plants and anchor rods for transmission towers.Reinforcing bars with special material properties requirelarge-quantity orders.

3.4—WeldingProvisions for welding are specifically excluded from

ASTM A615/A615M. Low-alloy steel reinforcing barsconforming to ASTM A706/A706M are intended forwelding; hence, the specification contains restrictions onchemical composition and carbon equivalent.

If it is necessary to make welded splices of ASTM A615/A615M reinforcing bars, it is important that the provisions ofAWS D1.4/AWS D1.4M be followed to obtain a ductileconnection. AWS D1.4/AWS D1.4M requires the calculationof the carbon equivalent, which in turn requires that thechemical composition of the bars to be welded be knowneither from information provided by the producer or bytesting a sample. Certified Mill Test Reports should berequested in the project specifications when the construction



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project contains welded reinforcing bars. ASTM A615/A615M reinforcing bars with higher carbon equivalentpercentages require a prescribed amount of preheat. Trace-ability of reinforcing bars to their Certified Mill Test Reportsafter fabrication is an important quality-control issue whenwelding ASTM A615/A615M bars. Welding of reinforcingbars conforming to ASTM A706/A706M should also beperformed in accordance with AWS D1.4/AWS D1.4M.ASTM A706/A706M limits the carbon equivalent to 0.55%,and AWS D1.4/AWS D1.4M requires little or no preheat forbars at or below this limit.

Connection of crossing bars by small arc welds, known astack welds, is not recommended. These welds can causestress concentrations that may lead to reduced strength andductility. If tack welding is authorized by the Architect/Engineer, the welds should be made in conformance with allthe requirements of AWS D1.4/AWS D1.4M (refer to ACI318-08, Section 7.5.4.).

3.5—Material testingAcceptance tests for compliance with ASTM specifications

require that the yield strength, tensile strength, andpercentage of elongation as well as the nominal weight(mass), bend test, deformation requirements, and phosphorouscontent be determined for a representative specimen of eachsize from each heat of reinforcing bar rolled. ASTM A370prescribes these test methods and procedures.

For reinforced concrete building projects designed inaccordance with ACI 318, the Architect/Engineer shouldspecify the reinforcing bars in accordance with ASTMA615/A615M, A706/A706M, or A996/A996M. The specialprovisions for seismic design in Chapter 21 of ACI 318-08require reinforcing bars to comply with ASTM A706/A706M. Chapter 21 of 318-08, however, permits the use ofGrades 40 and 60 (300 and 420) ASTM A615/A615M barswith the following limitations:

1. The actual yield strength cannot exceed the specifiedyield strength by more than 18,000 psi (120 MPa); and

2. The actual tensile strength cannot be less than 1.25times the actual yield strength.

Table 3.4 shows the standard fabricated bar bends and endhooks used in construction. These standard bends and endhooks have been established by ACI 315 in conjunction withthe Concrete Reinforcing Steel Institute, based on provisionsin ACI 318. For some bar sizes, the diameters of the bendsand hooks are larger than the minimum values specified byACI 318. The dimensions of the bar bends and hooks are thefinished bend diameters, which are measured on the inside ofthe bend. Pin sizes used by fabricators are based on Section 7.2of ACI 318-08. The slight straightening of the bent bar, knownas springback, results in a larger finished bend diameter.

Note in Table 3.4 that the pin diameters for the ASTMbend tests are slightly smaller (typically one-half or one bardiameter smaller) than the finished bend diameters used inconstruction. The basis for the smaller pin diameters is tohave a specimen tested to more severe requirements thanthose used in construction.

Additional testing criteria and restrictions on reinforcingbars have evolved to meet the special design and qualityassurance/quality control requirements for safety-relatedportions of nuclear power plants. ACI 359 permits only theuse of reinforcing bars meeting ASTM A615/A615M orA706/A706M. In addition, ACI 359 requires more frequenttensile testing than the ASTM specifications, that is, onetension test at a maximum frequency of 50 tons (45 t) perheat per bar size versus ASTM’s one test per heat per barsize. The basis for this exception is that ACI 359 considersthe ASTM test frequency inadequate for its special designrequirements because commercial heat sizes may be as muchas 250 tons (230 t) or more.

Another difference in ACI 359 concerns retest criteria fortension tests. ASTM A615/A615M and A706/A706M permitretests on two random specimens if the results of an originaltension specimen are within specified limits (Table 3.3).ACI 359 requires retests on two random specimens, but nolimits on the original test specimen results are imposed.

ACI 349 is similar to ACI 359 in that it permits onlyASTM A615/A 615M or A706/A706M bars. ACI 349 alsorequires one tension test for each 50 tons (45 t) of each barsize produced from each heat of steel.

3.6—Spirals and mats3.6.1 Spirals—Spiral reinforcement for columns is fabricated

from reinforcing bars conforming to ASTM A615/A615M orA706/A706M. Spirals may also be made from plain wire thatcomplies with ASTM A82/A82M or deformed steel wirethat complies with ASTM A496/A496M.

The fabrication of spirals (with the accompanying spacingdevices, if required) is generally done by reinforcing barfabricators. Not all fabricators of reinforcing bars producespirals; consequently, lead times may be extended in somelocations during times of peak demand.

3.6.2 Bar mats—This type of reinforcement usesdeformed reinforcing bars that conform to ASTM A615/A615M or A706/A706M. Bar mats are defined in ASTMA184/A184M as two layers of bars that are assembled atright angles to each other by welding. ASTM A184/A184Moutlines the requirements for welding, the testing of thewelds, tolerances, marking, and inspection.

The use of bar mats is advantageous when there is significantrepetition of identical mats; however, due to low usage, barmats may not be readily available in some geographic areas.Many reinforcing bar fabricating shops do not normallyproduce bar mats.

3.7—Corrosion protection productsACI 318 permits the use of epoxy-coated and zinc-coated

(galvanized) reinforcing bars as corrosion-protectionsystems in reinforced concrete structures. The bars to becoated should conform to Section 3.5.3.1 of ACI 318-08.ASTM A955/A955M covers stainless steel reinforcing bars.

Epoxy-coated reinforcing bars should conform to ASTMA775/A775M or A934/A934M. Two industry practicesexist: one is to coat straight bars and then fabricate the coatedbars (ASTM A775/A775M); the other is to prefabricate the



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bars and then coat them (ASTM A934/A934M). TheConcrete Reinforcing Steel Institute has a voluntary certifi-cation program for epoxy coating applicator plants.

Zinc-coated reinforcing bars should conform to ASTMA767/A767M. The Architect/Engineer should be aware ofoptional provisions in ASTM A767/A767M and specifythese requirements when appropriate. For instance, bars areusually galvanized after fabrication. In this case, the specifi-cation establishes minimum finished bend diameters for barsthat are fabricated before galvanizing, except that the barsmay be bent tighter if they are stress-relieved by a prescribedheat treatment process. Hence, the Architect/Engineershould specify which bars require special finished benddiameters; these are usually the smaller bar sizes for stirrupsand ties. ASTM A767/A767M includes two classes withdifferent weights of zinc coating. Class I (3.5 oz/ft2 [1070 g/m2])is normally specified for general construction. ACI 349 doesnot permit the use of zinc-coated reinforcing bars.

No uncoated reinforcing steel, or any other embeddedmetal dissimilar to zinc, should be permitted in the samestructural concrete member with or in close proximity togalvanized reinforcing bars, except as part of a cathodicprotection system. Galvanized bars should not be electricallycoupled to uncoated bars.

Standards ASTM A767/A767M, A775/A775M, andA934/A934M provide nonmandatory information regardingfield handling of coated bars. The specifier should prescribe

requirements in the project specification for: handling andplacing; job-site storage; tie wire; bar supports; touching upthe ends of bars cut at the job site; prohibiting flame-cuttingof epoxy-coated bars; limits on the amount of repairabledamaged coating; the repair of all damaged coating; andinternal vibrators for consolidating concrete. These fieldrequirements are provided in ACI 301.

Epoxy-coated bars are generally available throughout theU.S. Zinc-coated (galvanized) reinforcing bars are availablein limited areas. Because of inspection and the coating appli-cation process, delivery times might be extended comparedwith uncoated reinforcing bars.

ASTM A955/A955M includes three minimum yieldstrengths for stainless steel reinforcing bars: Grades 40, 60,and 75 (Grades 300, 420, and 520). The bar sizes are thesame as those in A615/A615M. Typically, stainless steel barslack a well-defined yield point. As a result, ASTM A955/A955M requires that the yield strength be determined as thestress corresponding to a prescribed strain of 0.35%. Interestis developing, mainly among several State Departments ofTransportation, in using stainless steel bars in corrosiveenvironments. Although the initial cost of stainless steel barsis relatively high, proponents contend the use of such barsbecomes attractive when a long service life and life-cyclecosts are factored into the economics of a project. Stainlesssteel bars have also been used in reinforced concrete struc-tures where nonmagnetic materials were required.

Table 3.4—ACI 318 standard minimum bends and ASTM bend requirements

ASTM specification Bar designation number Grades designations

Bend pin diameter(db = nominal bar diameter)

ASTM*

ACI

Standard† Stirrup/tie‡

A615/A615M

3, 4, 5 (10, 13, 16) 40, 60 (280, 420) 3-1/2db 6db 4db

6 (19) 40, 60, 75 (280, 420, 520) 5db 6db 6db

7, 8 (22, 25) 60, 75 (420, 520) 5db 6db 6db

9, 10, 11 (29, 32, 36) 60, 75 (420, 520) 7db 8db N/A

14, 18 (43, 57) 60, 75 (420, 520) 9db (90 degrees) 10db N/A

A706/A706M

3, 4, 5 (10, 13, 16) 60 (420) 3db 6db 4db

6, 7, 8 (19, 22, 25) 60 (420) 4db 6db 6db

9, 10, 11 (29, 32, 36) 60 (420) 6db 8db N/A

14, 18 (43, 57) 60 (420) 8db 10db N/A

A955/A955M

3, 4, 5 (10, 13, 16) 40, 60 (300, 420) 3-1/2db 6db 4db

6 (19) 40, 60, 75 (300, 420, 520) 5db 6db 6db

7, 8 (22, 25) 60, 75 (420, 520) 5db 6db 6db

9, 10, 11 (29, 32, 36) 60, 75 (420, 520) 7db 8db N/A

14, 18 (43, 57) 60, 75 (420, 520) 9db (90 degrees) 10db N/A

A1035/A1035M

3, 4, 5 (10, 13, 16) 100, 120 (690, 830) 3-1/2db 6db 6db

6, 7, 8 (19, 22, 25) 100, 120 (690, 830) 5db 6db 6db

9, 10, 11 (29, 32, 36) 100, 120 (690, 830) 7db 8db N/A

14, 18 (43, 57) 100, 120 (690, 830) 9db (90 degrees) 10db N/A*ASTM bend tests 180 degrees unless otherwise specified.†ACI standard bends 90 and 180 degrees.‡ACI stirrup/tie bends 90 and 135 degrees for bars No. 3 to No. 8 (No. 10 to No. 25) only.



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CHAPTER 4—PLAIN AND DEFORMED WIRE4.1—Introduction

Low-carbon cold-worked wire is used extensively inconstruction. Wire for concrete reinforcement may be plain,as defined by ASTM A82/A82M, or deformed, as defined byASTM A496/A496M. The ASTM mechanical requirementsare given in Table 4.1. Plain or deformed wire is used asconcrete reinforcement in building and bridge structures.This reinforcement is also used in sewer pipes, precastcomponents, and slabs-on-ground.

Plain steel wire used as concrete reinforcement ispermitted by ACI 318 for use in caisson, column, or pierspirals and in welded wire reinforcement (WWR) where thewelded intersections provide the bond strength. Deformedsteel wire is permitted in ACI 318 for use as general concretereinforcement. The deformations along the surface of thewire provide the bond strength. For deformed wire used inWWR, the deformations and the welded intersectionscombine to provide the bond strength.

4.2—Material propertiesLow-carbon wire is cold-worked by either drawing or

rolling the wire from hot-rolled rods. Thus, wire is differentfrom reinforcing bars, which are a hot-rolled product. Therods have a low carbon content—under 0.30% and areusually in the range of 0.08 to 0.16% carbon.

Low-carbon hot-rolled rod is drawn through dies toproduce plain wire of the desired size, or rolled throughdeforming rolls to produce deformed wire of the desired size.The drawing and rolling processes increase the yield andtensile strengths. Most low-carbon plain wire used inconcrete reinforcement is drawn through one or two dies,and most low-carbon deformed wire is rolled through at leasttwo sets of rolls. Because the dies and rolls wear during themanufacturing process, dimensional tolerances within theASTM standards provide for an allowable size range aboveand below the exact wire size. Plain wire size is determinedby measuring wire diameter, and deformed wire size is deter-mined by measuring wire weight per unit length.

Because the wire has a low carbon content, it generally hasgood welding characteristics and excellent bendabilityproperties. There are no specific requirements for weldingwire to wire in the field. The strength of cold-worked wiremay be reduced when field-welded.

ASTM A82/A82M and A496/A496M require that yieldstrength for plain or deformed wire be determined at a strain

of 0.50%. In accordance with Sections 3.5.3 and 3.5.4 of ACI318-08, however, the yield strength should be determined at astress corresponding to a strain of 0.35% for all material witha yield strength greater than 60,000 psi (420 MPa) up to80,000 psi (550 MPa). Plots of idealized stress-strain curvesfor various yield strength wires are shown in Fig. 4.1. A plotof the A615/A615M reinforcing bar is included as a reference.

Research at the University of Nebraska (Amorn et al. 2007)has shown that deformed wire, in the form of WWR with nowelds in the high stress region, has similar fatigue resistanceto that of reinforcing bars. There is presently no known dataavailable on impact resistance of low-carbon steel wire.

Table 4.1—ASTM mechanical property requirements for plain and deformed wireType of wire Minimum yield strength, psi (MPa) Minimum tensile strength, psi (MPa) Pin diameter for bend tests*

Plain(ASTM A82/A82M) 70,000 (485) 80,000 (550)

W7 (MW45) and smaller......................1dbLarger than W7 (MW45)......................2db

Deformed(ASTM A496/A496M) 75,000 (515) 85,000 (585)

D6 (MD39) and smaller.......................2dbLarger than D6 (MD39).......................4db

Plain stainless steel(ASTM 1022/A1022M) 70,000 (485) 80,000 (550) Same as for ASTM A82/A82M

Deformed stainless steel(ASTM 1022/A1022M) 75,000 (515) 85,000 (585) Same as for ASTM A496/A496M

*db = nominal diameter of specimen. Bend tests through 180 degrees for plain wire (ASTM A82/A82M) and 90 degrees for deformed wire (A496/A496M).

Fig. 4.1—Idealized stress-strain curves for cold-rolledASTM A82/A82M and ASTM A496/A496M wire.



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4.3—Wire size designationThe designation of wire sizes involves a letter-number

combination. ASTM uses “W” or “MW” to designate plainwire, and “D” or “MD” for deformed wire. The numberfollowing the W or D gives the cross-sectional area of thewire in hundredths of a square inch, and MW or MD givesthe cross-sectional area in square millimeters. For instance, aW5.0 (MW32) wire is a plain wire with a cross-sectional area of0.05 in.2 (32 mm2). D31.0 (MD200) indicates a deformed wirewith a cross-sectional area of 0.31 in.2 (200 mm2).

4.4—AvailabilityPlain wire (ASTM A82/A82M) used for WWR is generally

available in wire sizes from W0.5 (MW3) (0.080 in. [2.03mm] diameter) through W45 (MW290) (0.757 in. [19.22mm] diameter). Plain wire is used in the manufacture ofwelded wire for concrete reinforcement and is generallylimited to a minimum size of W1.4 (MW9) (0.135 in. [3.4 mm]diameter). Wire sizes smaller than W1.4 (MW9) are typicallyused in masonry reinforcement, and are normally galvanized.

Spirals fabricated from wire are subject to the sameavailability and lead time requirements as spirals usingASTM A615/A615M or A706/A706M hot-rolled plain bars.

Deformed wire (ASTM A496/A496M), most commonlyused in the manufacture of deformed WWR, is normallyavailable in wire sizes from D4 through D20 (MD26 throughMD129) (larger wire sizes from some producers are availableup to D45 [MD290]). Although some deformed welded wireis available in smaller sizes, Section 3.5.3.5 of ACI 318-08limits the minimum deformed wire size to D4 (MD26).

4.5—Corrosion protection productsASTM A884/A884M covers epoxy-coated wire and

WWR. Epoxy-coated wire is used as a corrosion protectionsystem in reinforced concrete structures or componentsexposed to chlorides. Availability varies depending ongeographic location; local manufacturers should becontacted for additional information.

Cold-worked wire can be galvanized to conform to ASTMA641/A641M. ASTM A123/A123M covers hot-dip galva-nizing of wire as well as other reinforcement. Local manu-facturers should be contacted for additional information.

ASTM A933/A933M covers vinyl-coated wire andWWR. Local manufacturers should be contacted for addi-tional information.

ASTM A1022/A1022M covers stainless steel wire andwelded wire for concrete reinforcement. Stainless steel wireand WWR are used in applications requiring resistance tocorrosion, controlled magnetic permeability, or both. Localmanufacturers should be contacted for additional information.

CHAPTER 5—WELDED WIRE REINFORCEMENT5.1—Introduction

Welded wire reinforcement, the material and its manufac-turing process, are covered by ASTM A185/A185M forWWR made from plain wire, and ASTM A497/A497M forWWR made from deformed wire or a combination ofdeformed and plain wire. Welded wire reinforcement wasformerly identified as welded wire fabric. Applications

include reinforcement for footings, foundations, slabs-on-ground, slabs on metal deck, two-way structural slabs, andwalls. Welded wire reinforcement is manufactured in flatsheets and rolls. Welded wire reinforcement sheets can bebent into various shapes such as stirrup baskets for beams,and closed shear and confinement cages for beams andcolumns. Welded wire reinforcement rolls made of small-diameter wire, up to W2.9 (MW19), are used for slabs-on-ground in some geographic regions.

Welded wire reinforcement is used extensively in theprecast concrete industry. Rolls are used for reinforcedconcrete pipe, and sheets are used for box culverts, wallpanels, and many other precast components.

Plain WWR uses the welded intersections to provide bondstrength and anchorage in the concrete. ACI 318 limits wirespacing in plain WWR to a maximum of 16 in. (400 mm)except for shear reinforcement where the maximum spacingis 24 in. (610 mm). Deformed WWR uses the combination ofdeformations along the surface of the wire and the weldedintersections to provide bond strength and anchorage in theconcrete.

5.2—Material propertiesASTM A185/A185M and A497/A497M define: the

minimum weld shear strength; tension, bend, and weld sheartest methods and apparatus; and permissible variations,packaging, and identification requirements. ASTM-specifiedminimum mechanical property requirements for steel wiresin WWR are summarized in Table 5.1.

ACI 318 requires a yield strength of 60,000 psi (420 MPa)for design unless the WWR is specified and furnished with aminimum yield strength measured at 0.35% strain. In thiscase, the tested minimum yield strength can be used as notedin the following section.

Recent research at the University of Nebraska (Amorn etal. 2007) showed that deformed wire, in the form of WWRwith no welds in the high stress region, has similar fatigueresistance to that of reinforcing bars. The fatigue resistanceis slightly reduced when welds are present in the high-stress

Table 5.1—ASTM mechanical property requirements for steel wires in welded wire reinforcement

Wire size

Minimum yield strength,*psi (MPa)

Minimum tensile strength,

psi (MPa)

Minimum weld shear strength,†

lb (N)

Welded plain wire (ASTM A185/A185M)

W1.4 (MW9) toW45 (MW290)

65,000(450)

75,000(515)

35,000Aw (241Aw)

Welded deformed wire (ASTM A497/A497M)

D4 (MD26)to D45 (MD290)

70,000(485)

80,000(550)

35,000Aw(241Aw)

Welded plain and deformed stainless steel wire (ASTM A1022/A1022M)

W1.2 (MW8)to W45 (MW290)

65,000(450)

75,000(515)

35,000Aw(241Aw)

D1 (MD4.5)to D45 (MD290)

70,000(485)

80,000(550)

35,000 Aw(241Aw)

*The minimum yield strength is determined at a strain of 0.005.†Aw = nominal area of larger wire in in.2 (mm2). The ratio of the area of the smallerwire to the area of the larger wire must be at least 0.40.



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region. There are presently no known data available onimpact resistance of WWR.

5.3—Higher-strength welded wire reinforcementThe yield strengths in ASTM A82/A82M for plain wire

and in A496/A496M for deformed wire are based on a strainof 0.5%. ACI 318 permits the use of design yield strengthsup to 80,000 psi (550 MPa) for flexural, shear, and confine-ment reinforcement if the yield strength is measured at astrain of 0.35% (ACI Committee 439 1999). Section 11.4.2of ACI 318-08 permits the design yield strength of up to80,000 psi (550 MPa) for deformed WWR used for shearreinforcement.

The manufacturer should certify that the wire used in theWWR meets the more restrictive strain requirements of ACI318. The Architect/Engineer uses this provision to specifyhigher yield strengths in designs. Materials with yieldstrengths higher than the minimum (65,000 psi [450 MPa]for ASTM A185/A185M and 70,000 [485 MPa] for ASTMA497/A497M) up to 80,000 psi (550 MPa) are available.Certified Mill Test Reports are available from manufacturersfor all materials.

5.4—Welded wire reinforcement stylesRepresentative styles of WWR are given in Table 5.2. An

illustrative example of a style is as follows:

6 x 12 – W16 x W8 (in-lb.)

152 x 305 – MW104 x MW52 (SI)

This denotes a WWR style made of plain wire in which:Spacing of longitudinal wires = 6 in. (152 mm);Spacing of transverse wires = 12 in. (305 mm);Size of longitudinal wires =

W16 (MW104) (area = 0.16 in.2 [104 mm2]); andSize of transverse wires =

W8 (MW52) (area = 0.08 in.2 [52 mm2]).

A welded deformed wire style would be noted in the samemanner by substituting a D(MD) prefix to the wire sizes forthe W(MW) prefix.

5.5—AvailabilityAs noted in previous sections on plain and deformed wire,

welded wire for concrete reinforcement is available withminimum wire sizes of W1.4 (MW9) for plain WWR and D4(MD26) for deformed WWR. The majority of manufacturersproduce WWR that uses wire sizes up to W20 (MW129) orD20 (MD129), with some capable of producing wire sizes upto W45 (MW290) or D45 (MD290). Most manufacturers, byspecial order, are capable of providing styles with variablewire spacings in both directions.

5.6—Minimum quantity requirementsEconomy can be achieved by specifying standard styles.

Welded wire manufacturers usually stock the typical standardstyles that most users are aware of, as well as heavier stylesthat the industry has listed in publications, such as the WireReinforcement Institute’s WWR-500, and in technical factsheets on current product information.

5.6.1 Stock styles—Certain styles of plain WWR arecarried in stock either at the producing mills or warehouses.While practice varies somewhat with different manufacturersand localities, the representative styles listed in Table 5.2 areusually available.

Some styles of plain WWR may be obtained in roll form.Typical roll widths and lengths of plain WWR are:• U.S. (except West Coast): 60 in. x 150 ft (1524 mm x

45.7 m); and• West Coast of U.S.: 84 in. x 150 ft or 200 ft (2134 mm

x 45.7 m or 61.0 m).It is recommended that rolls be straightened and cut to size

before placement.5.6.2 Nonstock styles—It is often desirable to order WWR

sheets or rolls specifically produced to meet the reinforce-ment requirements and dimensions for individual projects.

Table 5.2—Representative styles of metric welded wire reinforcement with equivalent in.-lb units

SI styles* (MW = plain wire)† Area, mm2/m Mass, kg/m2 Inch-pound styles* (W = plain wire)† Area, in.2/ft Weight, lb/CSF‡

102 x 102 – MW9 x MW9 88.9 1.51 4 x 4 – W1.4 x W1.4 0.042 31

102 x 102 – MW13 x MW13 127.0 2.15 4 x 4 – W2.0 x W2.0 0.060 44

102 x 102 – MW19 x MW19 184.2 3.03 4 x 4 – W2.9 x W2.9 0.087 62

102 x 102 – MW26 x MW26 254.0 4.30 4 x 4 – W4.0 x W4.0 0.120 88

152 x 152 – MW9 x MW9 59.3 1.03 6 x 6 – W1.4 x W1.4 0.028 21

152 x 152 – MW13 x MW13 84.7 1.46 6 x 6 – W2.0 x W2.0 0.040 30

152 x 152 – MW19 x MW19 122.8 2.05 6 x 6 – W2.9 x W2.9 0.058 42

152 x 152 – MW26 x MW26 169.4 2.83 6 x 6 – W4.0 x W4.0 0.080 58

305 x 305 – MW54 x MW54 175.7 3.08 12 x 12 – W8.3 x W8.3 0.083 63

305 x 305 – MW61 x MW61 199.0 3.47 12 x 12 – W9.4 x W9.4 0.094 71

305 x 305 – MW97 x MW97 317.5 5.52 12 x 12 – W15 x W15 0.150 113

305 x 305 – MW110 x MW110 362.0 6.25 12 x 12 – W17.1 x W17.1 0.171 128*Welded wire reinforcement styles listed in this table are representative examples of potential styles or spacings. There are an unlimited number of styles that design engineers canuse. This listing does not restrict other wire sizes and styles from being specified. For other available styles or wire sizes, consult WRI publications or discuss with WWR manufacturers.†Wires may also be deformed. Prefix D (MD) should be used, except where only W (MW) is required by building codes (usually less than a W4 [MW26]). Wire sizes can be spec-ified in 0.001 in.2 increments (1 mm2 increments for metric wire).‡CSF = 100 ft2.



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The minimum quantity requirements for specific nonstockstyles are governed by the manufacturing process require-ments, which vary with different manufacturers. Thefollowing examples are merely a guide to illustrate thegeneral requirements.1. Longitudinal spacing, wire size, and sheet or roll width

changes usually require quantities of 10 to 20 tons (9 to18 t) per style;

2. Transverse wire spacing and size, side and end over-hangs, and length changes usually require quantities of2 to 5 tons (2 to 5 t) per style; and

3. The average weight for the total quantity in an order for anystyle should be approximately 20 tons (18 t). There areexceptions for less than truckload quantities, and these arehandled on individual project requests with the manufac-turer’s acceptance. Before selecting nonstock styles, theArchitect/Engineer should check with local manufacturersfor both maximum and minimum quantities available.

For nonstock WWR styles, the following guidelines leadto the greatest production economies:1. The most important factor affecting economy is keeping

the longitudinal wire size and spacing the same for asingle production run. It is possible, however, to varywire sizes and spacings to obtain required areas of steel.Some manufacturers can produce variable-steppedspacing of longitudinal wires;

2. The second most important factor is that the transversewire size and spacing are the same for a single productionrun. Spacing of transverse wires is typically 3, 4, 6, 8,12, 16, and 18 in. (75, 100, 150, 200, 300, 400, and 460mm). For applications other than structural, particularlyfor slab-on-ground installations, wire spacing can be aslarge as 18 in. (460 mm) or greater, depending on themanufacturer; and

3. As specified in the dimensions section of the corre-sponding ASTM specification for welded wire, amaximum allowable size differential of wires beingwelded together is maintained to ensure adequate weldshear strength. For both plain and deformed wire reinforce-ment, ASTM requires the smaller wire to have an area of40% or more of the larger wire and with a minimum weldshear strength in pounds force of 35,000 times the area ofthe larger wire in square inches (in Newtons of 241 timesthe area of the larger wire in square millimeters).

Although it is possible to manufacture rolls using wire inthe W12 (MW77) or D12 (MD77) and larger, some manu-facturers recommend that sheets be specified essentially forall construction project applications as well as precast/prestressed structural members. Welded wire reinforcementfor pipe, representing a major part of the welded wireindustry, however, is manufactured in rolls using wire sizesof W12 (MW77) and larger.

Welded wire reinforcement may also be used as stirrupand tie reinforcement in beams and columns (Furlong et al.1991; Guimaraes et al. 1992). Most manufacturers havehydraulic benders available to form sheets of WWR intomany stirrup and tie configurations. Refer to Griezic et al.(1994) for tests of deformed welded wire stirrups.

5.7—Corrosion protection productsASTM A884/A884M covers epoxy-coated wire and

WWR. Epoxy-coated welded wire is used as a corrosionprotection system in reinforced concrete structures orcomponents exposed to chlorides. Availability variesdepending on geographic location; local manufacturersshould be contacted for additional information.

Cold-worked wire can be galvanized to conform to ASTMA641/A641M for use in producing WWR. Alternatively,WWR can be galvanized after fabrication. ASTM A123/A123M covers the hot-dip galvanizing of WWR as well asother reinforcement. A new ASTM standard specificallycovering galvanized WWR is in process.

ASTM A933/A933M covers vinyl-coated wire and WWR.Local manufacturers should be contacted for additional infor-mation. ASTM A1022/A1022M covers stainless steel wireand welded wire for concrete reinforcement. Stainless steelwire and WWR is used in applications requiring resistance tocorrosion, controlled magnetic permeability, or both. Localmanufacturers should be contacted for additional information.

CHAPTER 6—PRESTRESSING REINFORCEMENT6.1—Introduction

The previous sections of this report addressed passivereinforcement. Prestressing steel is an active reinforcement.The term “active” describes a prestressing system that applies asustained force to a structural member, regardless of the otherapplied loads on that member. Because the magnitude of forcethat the prestressing system delivers to a structural memberis of prime importance, the mechanism of transferring thatforce from the prestressing steel to the structural member is amajor consideration. The transfer mechanism selected forany prestressing technique has a direct influence on materialproperty requirements.

In pretensioned prestressed concrete, the force is firstapplied to the prestressing steel and then maintained whileconcrete is placed around the prestressing steel and cured.After the concrete has reached specified strength, theprestressing force is transferred to the concrete by bond tothe prestressing steel. Prestressing reinforcement forprestressed concrete consists primarily of strands.

In post-tensioning systems, after the concrete has reacheda prescribed compressive strength, the force is applied fromthe prestressing steel to anchors and bearing plates, and thento the concrete member being prestressed. Prestressing steelfor post-tensioned members includes a wide spectrum ofmaterials. Wires, bars, or strands are used interchangeably inpost-tensioned members, depending upon the economics ofthe prestressing steel, the anchor system, the availability ofthe post-tensioning systems, and the considerations for themembers being post-tensioned. In recent years, wire tendonshave rarely been used, especially after the cessation of thepost-tensioning used in nuclear power plant construction.Wire tendons are available if detensioning for inspectionor retensioning of unbonded tendons to compensate forlosses in the post-tensioning force is required, or if no slipanchorages are needed. At present, their most common use isfor tendon replacement in nuclear containments.



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A wide variety of mechanisms is used to transfer theprestress force from the prestressing steel in post-tensionedconstruction. Most commonly used in the U.S. are wedgegrips for strands, threaded connectors for bars, or upset ends(button heads) on the prestressing wires. The performance ofthe anchorage and bearing plate system and its effect on theprestressing steel may affect the performance of the post-tensioning system to a greater degree than variables in theprestressing steel. The prestressing steel may be bonded tothe surrounding concrete after the prestressing force is trans-ferred by injecting grout into the duct around the tendon, orit may be left unbonded and protected with a corrosion inhibitor.When the tendons are external to the member, thoughgrouted, they are considered unbonded. The prestressingsteel also imparts force to the member at points of curvatureof the tendon, such as at tendon deflectors in pretensioned

girders (harped or draped strands) or along lengths of curvedtendons in post-tensioned members.

6.2—Material propertiesReinforcement for prestressed concrete may consist of

strands as defined by ASTM A416/A416M, bars as definedby ASTM A722/A722M, or high-strength wires as definedby ASTM A421/A421M. Compacted strands (ASTM A779/A779M), indented strands (ASTM A886/A886M), and two-and three-wire strands (ASTM A 910/A 910M) are not listedin ACI 318. The lack of listing in ACI 318 does not,however, preclude their use (refer to Sections 3.5.6.2 and 1.4in ACI 318-08). Mechanical properties for various types ofprestressing steel are summarized in Tables 6.1 and 6.2.Idealized stress-strain curves for several prestressing steelsare shown in Fig. 6.1.

Table 6.1—ASTM mechanical property requirements for prestressing wire and strandASTM A421/A421M wire

Size, in. (mm)

Minimum yield strength, psi (MPa)

Minimum tensile strength, psi (MPa) Minimum elongation, percent in a 10 in.

(250 mm) gauge length

Stress-relieved Low-relaxation

Type BA Type WA Type BA Type WA Type BA Type WA

0.192 (4.88) * 212,500 (1465) * 225,000 (1550) * 250,000 (1725) 4.0

0.196 (4.98) 204,000 (1407) 212,500 (1465) 216,000 (1490) 225,000 (1550) 240,000 (1655) 250,000 (1725) 4.0

0.250 (6.35) 204,000 (1407) 204,000 (1407) 216,000 (1490) 216,000 (1490) 240,000 (1655) 240,000 (1655) 4.0

0.276 (7.01) 199,750 (1377) 199,750 (1377) 211,500 (1460) 211,500 (1460) 235,000 (1620) 235,000 (1620) 4.0

ASTM A416/A416M strand

Size, in. (mm) Grade

Minimum yield strength, psi (MPa)Minimum tensile

strength, psi (MPa)

Minimum elongation, percent in a 24 in.

(600 mm) gauge lengthStress-relieved Low-relaxation

All sizes† 270 (1860) 229,500 (1580) 243,000 (1675) 270,000 (1860) 3.5

All sizes† 250 (1725) 212,500 (1465) 225,000 (1550) 250,000 (1725) 3.5

ASTM A779/A779M compacted strand‡



strength, psi (MPa)



0.5 (12.7) 270 (1860) 234,900 (1620) 243,000 (1675) 270,000 (1860) 3.5

0.6 (15.2) 260 (1800) 226,200 (1565) 234,000 (1620) 260,000 (1800) 3.5

0.7 (18.0) 245 (1700) 213,200 (1480) 220,500 (1530) 245,000 (1700) 3.5

ASTM A886/A886M indented strand‡



strength, psi (MPa)



All sizes† 270I (1860I) 229,500 (1580) 243,000 (1675) 270,000 (1860) 3.5

All sizes† 250I (1725I) 212,500 (1465) 225,000 (1550) 250,000 (1725) 3.5

ASTM A910/A910M two- and three-wire strand‡



strength, psi (MPa)



All sizes† 270 (1860) 229,500 (1580) 243,000 (1675) 270,000 (1860) 3.5

All sizes† 250 (1725) 212,500 (1465) 225,000 (1550) 250,000 (1725) 3.5

*Not commonly furnished in Type BA wire.†Refer to Table 6.3 for sizes.‡Not listed in ACI 318.



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Seven-wire strand for prestressing applications consists ofone center wire and six helically formed outer wires with auniform pitch of not less than 12 nor more than 16 times thenominal strand diameter. The most widely used type ofstrand, which is regarded as the standard type, is low-relax-ation strand. Because the use of stress-relieved (normalrelaxation) strand under ASTM A416/A416M is largelyunavailable, this type of strand is not discussed in this report.Low-relaxation strand specified under ASTM A416/A416Mis produced in two grades, Grade 250 (1725) and Grade 270(1860), with minimum tensile strengths of 250,000 and270,000 psi (1725 and 1860 MPa), respectively, based onnominal area of the strand.

Compacted seven-wire strand (compacted by drawingthrough a die and subsequently stress-relieved) producedunder ASTM A779/A779M has a different strength levelspecified for each of three different sizes. ASTM A421/A421M, A779/A779M, and A886/A886M also provide(under Supplement I of each specification) for low-relax-ation strand and relaxation testing.

For low-relaxation strand or wire, relaxation losses after1000 hours should not be more than 2.5% when initiallyloaded to 70% of specified minimum tensile strength, normore than 3.5% when loaded to 80% of specified minimumtensile strength at 68°F (20°C), as specified in ASTM A416/A416M and A910/A910M and in each supplement of ASTMA421/A421M, A779/A779M, and A886/A886M. For agiven loading over a given time period, the relaxation lossfor low-relaxation strand is about one-fourth that of a stress-relieved strand.

As required in ASTM A416/A416M and A910/A910M,and in each supplement of A421/A421M, A779/A779M,and A886/A886M, the minimum yield strength for low-relaxation strand and wire measured at 1% extension underload should not be less than 90% of specified minimumtensile strength.

Material such as high-strength alloy steel bar is used as aprestressing reinforcement. ASTM A722/A722M specifiesthat the mechanical properties of such bar (Table 6.2) beobtained from tests on full-size bar test specimens. Supple-mentary requirements for ASTM A722/A722M provide forbend tests, minimum reduction-of-area, and report of chemicalcomposition.

Wire produced under ASTM A421/A421M varies inminimum tensile strength depending on wire size. It may beused in applications that require cold-end deformations foranchorage, Type BA (button anchorage), and, for applica-tions that require wedge anchorage of the ends, Type WA(wedge anchorage) with no cold-end deformation. ASTMA421/A421M also provides (under Supplement I) for low-relaxation wire and relaxation testing for the product.

ACI 318 references ASTM A416/A416M, A421/A421M,and A722/A722M with no additional material requirements.ACI 318, however, does require that post-tensioning anchor-ages and couplers for bonded and unbonded prestressing

Table 6.2—Summary of ASTM A722/A722M mechanical properties and other requirements for uncoated high-strength steel bar for prestressing concrete

Mechanical properties*Type I

(plain bars)Type II

(deformed bars)

Minimum tensile strength 150,000 psi(1035 MPa)

150,000 psi(1035 MPa)

Minimum yield strength 127,500 psi(880 MPa)

120,000 psi(830 MPa)

Strain at yield strength(extension under load method) 0.7% 0.7%

Minimum percentage of elongation:Gauge length of 20 bar diameters, orGauge length of 10 bar diameters

4%

7%

4%

7%

Nominal diameter ranges 3/4 to 1-3/8 in.(19 to 35 mm)

5/8 in. to 2-1/2 in.(15 to 65 mm)

Chemical requirements

Maximum % (heat):0.040 phosphorus, 0.050 sulfur

Maximum % (finished bar):0.048 phosphorus, 0.058 sulfur

Supplementary requirements (apply only when specified by purchaser)

Bend test, Type I and II(135 degrees)

Nominal diameter,in. (mm)

Bend pin diameter(db = nominal bar

diameter)

5/8, 3/4, 1 (15, 20, 26)1-1/4, 1-3/8 (32, 36)1-3/4, 2-1/2 (46, 65)

6db8db

10db

Reduction of area 20% minimum —*Bars to be cold-stressed to not less than 80% minimum tensile strength and thenstress-relieved to produce prescribed mechanical properties.

Fig. 6.1—Idealized stress-strain curves of prestressing steel.



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tendons develop at least 95% of the tensile strength of thetendons, when tested in an unbonded condition, withoutexceeding anticipated set. For bonded tendons, anchoragesand couplers should be located so that 100% of the specifiedtensile strength of the tendons could be developed at criticalsections after the tendons are bonded in the member.

ACI 423.3R has additional recommendations forunbonded tendons. Test assemblies for these additionalrecommended tests should consist of standard productionquality components, and the tendons should be at least 10 ft(3.05 m) long. The assembly for the static test should betested in a manner to allow accurate determination of theyield strength, tensile strength, and percent elongation of thecomplete tendon. Assemblies for the dynamic tests shouldwithstand, without failure, 500,000 cycles from 60 to 66% ofminimum specified tensile strength and 50 cycles from 40 to80% of minimum specified tensile strength. The specimenused for the second fatigue test need not be the same as thatused for the first fatigue test.

Some applications may require more severe dynamictesting. These dynamic/fatigue test requirements and otherdetailed requirements for post-tensioning systems arepresented in the Post-Tensioning Institute’s Post-TensioningManual and ACI 423.7.

Requirements for prestressing application on safety-related portions of nuclear power plants are covered by ACI349 and 359. ACI 349 essentially parallels the requirementsin ACI 318. ACI 359, however, identifies performance testand production test requirements. Performance tests requiretendon assemblies to be statically tested with their yieldstrength, tensile strength, and elongation reported. The tensilestrength of the assembly should be at least the minimumspecified tensile strength of the prestressing steel and theelongation at least 2% over a 100 in. (2540 mm) gage length.

ACI 349 and 359 require one high-cycle dynamic testperformed without failure, as also recommended in ACI

423.3R. The stress relaxation properties of the prestressingsteel should also be determined by test in accordance withSupplement I of ASTM A421/A421M, A779/A779M, orA886/A886M. ACI 359 requires a minimum of three 1000-hourrelaxation tests. Production testing should be performed inaccordance with the applicable ASTM specification.

6.3—AvailabilityLow-relaxation prestressing strands (ASTM A416/A416M),

high-strength steel bars (ASTM A722/A722M), andprestressing wires (ASTM A421/A421M) are generally avail-able as part of prestressing systems that include complete tendonswith their anchorage devices, ducts, and jacking equipment.

Low-relaxation prestressing strand (ASTM A416/A416M)is generally available throughout the U.S. in the sizes noted inTable 6.3. Type II uncoated high-strength steel bars forprestressing concrete (ASTM A722/A722M, deformed bar)are available throughout the U.S. in the sizes noted in Table 6.2.

Stress-relieved strands (ASTM A416/A416M), Type Ihigh-strength steel plain bars (ASTM A722/A722M), andprestressing wires (ASTM A421/A421M) may be purchasedby special order. Stress-relieved strands (ASTM A416/A416M) and Type I high-strength steel plain bars (ASTMA722/A722M), however, are generally not available in theU.S. The post-tensioning systems in the market no longeruse them because of their much higher relaxation lossescompared to the low-relaxation strands.

6.4—Corrosion protection productsBesides the ASTM standard prestressing reinforcement

discussed previously, a variety of strands for corrosionprotection is also available. These special applications areepoxy-coated seven-wire strand, galvanized strand, andstainless steel strand.

Epoxy-coated strand has been used in prestressing appli-cations where corrosion control is of paramount importance,such as piles, bridge decks and girders, stay cables, parkingstructures, replacement tendons in parking structures,ground anchors (tiebacks), fender piles, and floating docks inboth pretensioned and post-tensioned systems. ASTM A882/A882M prescribes requirements for filled epoxy-coatedseven-wire strand. The strand is coated with epoxy using theelectrostatic fusion-bonded process similar to that used forcoating nonprestressed reinforcing bars, wire, and WWR. Infilled strands, which are the standard type, the interstices(that is, the space in between the wires) are filled with epoxyto minimize migration of corrosive media. The use of filledepoxy-coated strand prevents water from penetrating into theinterior of the strand through the interstices between thewires, thereby preventing internal corrosion. Grit may beapplied to the surface of the epoxy to improve bond strength.

The strand coating is sufficiently flexible to allowstretching to high levels of strain without the formation ofholidays (pinholes not discernible to the unaided eye).Unlike galvanized strand, mechanical properties such asstrength and ductility are not affected by the coating process.Relaxation for unfilled epoxy-coated strand is 4%, 6.5% forfilled epoxy-coated strand, and only 2.5% for uncoated

Table 6.3—Available sizes of prestressing strandASTM A416/A416M strand and ASTM A886/A886M indented strand

Nominal diameter, in. (mm)

ASTM A416/A416M strand

designation

Nominal area, in.2 (mm2)

Grade 250 (1725) Grade 270 (1860)

1/4 (6.35) 6 0.036 (23.2) Not available

5/16 (7.94) 8 0.058 (37.4) 0.061 (39.4)*

3/8 (9.53) 9 0.080 (51.6) 0.085 (54.8)

7/16 (11.11) 11 0.108 (69.7) 0.115 (74.2)

1/2 (12.70) 13 0.144 (92.9) 0.153 (98.7)

6/10 (15.24) 15 0.216 (139.4) 0.217 (140.0)

ASTM A910/A910M two- and three-wire strand

Nominal diameter, in. (mm) Strand designation

0.228 (5.8) 2 x 0.114 (2 x 2.90)

0.189 (4.8) 3 x 0.089 (3 x 2.25)

0.205 (5.2) 3 x 0.095 (3 x 2.40)

0.244 (6.2) 3 x 0.114 (3 x 2.90)

0.256 (6.5) 3 x 0.118 (3 x 3.00)

0.295 (7.5) 3 x 0.138 (3 x 3.50)

0.340 (8.6) 3 x 0.158 (3 x 4.00)*For ASTM A886/886M; not available for ASTM A416/A416M.



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strand. Tests conducted in 1985 at Fritz Engineering Laboratoryof Lehigh University and by Wollmann et al. (1996)concluded that fatigue resistance is improved by reducingthe fretting (damage from rubbing) between individualstrands and between the strands and metal ducts usingepoxy-coated strands. Filled epoxy-coated strand is alsoavailable for use in prestressed and post-tensioned concrete.

Galvanized strand has been used in prestressed circular tanksand as barrier cables for parking garages. It should be noted thatdue to the thermal effects during hot-dip galvanizing and thereduced steel area for the same overall strand diameter, galva-nized strands have lower strengths and higher ductility thanuncoated prestressing strands of the same nominal diameter.

Stainless steel strands have been used in special applicationsthat require, in addition to moderate corrosion resistance, alow magnetic permeability, such as prestressed concreteused in piles and piers for demagnetizing stations. There isalso some interest in barrier cable applications, but the highcost of stainless steel can be a factor. Although there is nocurrent ASTM specification for stainless steel strand forprestressed concrete, ASTM A368 for stainless steel strandis intended for use as guy wires, overhead ground wires, andsimilar purposes.

6.5—Other prestressing reinforcementStrands up to 300 ksi (2070 MPa) tensile strength with

270 ksi (1860 MPa) yield strength are now produced,although availability is limited. All other properties conformto ASTM A416/A416M. Due to the 11% increase in tensilestrength of this steel over steel with 270 ksi (1860 MPa)tensile strength, an economic advantage results from the useof this steel. A noteworthy application is the use of 300 ksi(2070 MPa) epoxy-coated strands to replace corrodedtendons in parking structures; for example, 15/32 in. (11.9 mm),300 ksi (2070 MPa) epoxy-coated strand could replace 1/2 in.(12.70 mm), 270 ksi (1860 MPa) uncoated strand.

Many other sizes of prestressing strand not noted in Table 6.3are made by manufacturers as special orders. For these andthe other types discussed in this section, it is recommendedthat the suppliers be contacted directly.

CHAPTER 7—DEVELOPMENTSIN REINFORCING STEEL

There have been several developments regarding reinforcingsteel. ACI adopted ACI 408.3R, which permits the use ofreinforcing bars with increased height and closer spacing ofthe ribs or transverse deformations than used on currentlyproduced reinforcing bars. An ASTM specification for low-carbon chromium steel reinforcing bar has also been introduced.

7.1—High relative rib area reinforcing barsBased on bond research and specimen tests conducted

primarily at the University of Kansas, ACI 408.3R prescribestensile development and splice length requirements when andif commercial production of high relative rib area reinforcingbars is initiated. These reinforcing bars have a ratio of ribbearing area to bar surface area that is 50 to 100% more thantypical reinforcing bars currently in production. This highrelative rib area provides for a reduction in tension developmentand lap splice lengths when the bars are confined by transversereinforcement.

7.2—Low-carbon, chromium steel reinforcing barsIn 2004, ASTM issued A1035/A1035M for low-carbon,

chromium steel reinforcing bars with a single minimum yieldstrength of 100,000 psi (690 MPa), designated Grade 100 [690].In 2007, bars with a minimum yield strength of 120,000 psi(830 MPa), designated Grade 120 [830], were added to thisspecification. Bar sizes and deformation requirements are thesame as in the other ASTM reinforcing bar specifications.Idealized stress-strain curves for these two grades of A1035/A1035M steel are shown in Fig. 7.1. These bars lack a well-defined yield point. Designers should note that ASTM A1035/A1035M requires the yield strengths of 100,000 and120,000 psi, designated Grade 100 [690] and Grade 120 [830]respectively, be determined using the 0.2% offset method.ACI 318 had required the yield strength be determined at0.35% strain for yield strengths over 60,000 psi (420 MPa).ASTM A1035/A1035M requires a minimum yield strength of80,000 psi (550 MPa) for Grade 100 [690] bars, and 90,000 psi(620 MPa) for Grade 120 [830] bars when yield strength is

Fig. 7.1—Idealized stress-strain curves for ASTM A1035/A1035M reinforcing bars.Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=University of Texas Revised Sub Account/5620001114, User=wer, weqwe


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determined at 0.35% strain. Design should address properdevelopment and lap splice lengths for this higher yield strengthbar as well as the potential for increased cracking and deflec-tions due use of higher bar stresses. A Summary Report bySeliem et al. (2009) addresses the bond behavior of this steel.

CHAPTER 8—REFERENCES8.1—Referenced standards and reports

The various documents used in the development of thisreport follow. Because some of these documents are revisedfrequently, the reader is advised to contact the sponsoringorganization to obtain the latest revision.

American Concrete Institute301 Specifications for Structural Concrete315 Details and Detailing of Concrete Reinforcement318 Building Code Requirements for Structural Concrete349 Code Requirements for Nuclear Safety-Related

Concrete Structures359 Code for Concrete Reactor Vessels and Contain-

ments, Section III, Division 2 of the ASME Boilerand Pressure Vessel Code

408.3R Guide for Splice and Development Length ofHigh Relative Rib Area Reinforcing Bars in Tension

423.3R Recommendations for Concrete MembersPrestressed with Unbonded Tendons

423.7 Specification for Unbonded Single-StrandTendon Materials and Commentary

ASTM InternationalA82/A82M Standard Specification for Steel Wire,

Plain, for Concrete ReinforcementA123/A123M Standard Specification for Zinc (Hot-Dip

Galvanized) Coatings on Iron and SteelProducts

A184/A184M Standard Specification for Welded DeformedSteel Bar Mats for Concrete Reinforcement

A185/A185M Standard Specification for Steel WeldedWire Reinforcement, Plain, for Concrete

A368 Standard Specification for Stainless SteelWire Strand

A370 Standard Test Methods and Definitions forMechanical Testing of Steel Products

A416/A416M Standard Specification for Steel Strand,Uncoated Seven-Wire for Prestressed Concrete

A421/A421M Standard Specification for Uncoated Stress-Relieved Steel Wire for Prestressed Concrete

A496/A496M Standard Specification for Steel Wire,Deformed, for Concrete Reinforcement

A497/A497M Standard Specification for Steel Welded WireReinforcement, Deformed, for Concrete

A615/A615M Standard Specification for Deformed and PlainCarbon-Steel Bars for Concrete Reinforcement

A641/A641M Standard Specification for Zinc-Coated(Galvanized) Carbon Steel Wire

A706/A706M Standard Specification for Low-Alloy SteelDeformed and Plain Bars for ConcreteReinforcement

A722/A722M Standard Specification for Uncoated High-Strength Steel Bar for Prestressing Concrete

A767/A767M Standard Specification for Zinc-Coated(Galvanized) Steel Bars for Concrete Rein-forcement

A775/A775M Standard Specification for Epoxy-CoatedSteel Reinforcing Bars

A779/A779M Standard Specification for Steel Strand,Seven-Wire, Uncoated, Compacted, Stress-Relieved for Prestressed Concrete

A882/A882M Standard Specification for Filled Epoxy-Coated Seven-Wire Prestressing Steel Strand

A884/A884M Standard Specification for Epoxy-CoatedSteel Wire and Welded Wire Fabric forReinforcement

A886/A886M Standard Specification for Steel Strand,Indented, Seven-Wire Stress-Relieved forPrestressed Concrete

A910/A910M Standard Specification for Uncoated,Weldless, 2- and 3-Wire Steel Strand forPrestressed Concrete

A933/A933M Standard Specification for Vinyl (PVC)Coated Steel Wire and Welded Wire Fabricfor Reinforcement

A934/A934M Standard Specification for Epoxy-CoatedPrefabricated Steel Reinforcing Bars

A955/A955M Standard Specification for Deformed andPlain Stainless-Steel Bars for ConcreteReinforcement

A996/A996M Standard Specification for Rail-Steel andAxle-Steel Deformed Bars for ConcreteReinforcement

A1022/A1022M Standard Specification for Deformed andPlain Stainless Steel Wire and Welded Wirefor Concrete Reinforcement

A1035/A1035M Standard Specification for Deformed andPlain, Low-carbon, Chromium, Steel Barsfor Concrete Reinforcement

D5942 Withdrawn Standard: ASTM D5942-96Test Method for Determination of CharpyImpact Strength (withdrawn 1998)

American Welding SocietyAWS D1.4/AWS D1.4M Structural Welding Code—Reinforcing Steel

Concrete Reinforcing Steel InstituteManual of Standard Practice

Post-Tensioning InstitutePost-Tensioning Manual

Wire Reinforcement Institute, Inc.WWR-500 Manual of Standard Practice—Structural

Welded Wire Reinforcement

The previously mentioned publications may be obtainedfrom the following organizations:



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American Concrete InstituteP.O. Box 9094Farmington Hills, MI 48333-9094www.concrete.org

ASTM International100 Barr Harbor Dr.West Conshohocken, PA 19428-2959www.astm.org

American Welding Society550 NW Lejune Rd.Miami, FL 33135www.aws.org

Concrete Reinforcing Steel Institute933 North Plum Grove Rd.Schaumburg, IL 60173-4758www.crsi.org

Post-Tensioning Institute38800 Country Club Dr.Farmington Hills, MI 48331www.post-tensioning.org

Wire Reinforcement Institute, Inc.942 Main St., Suite 300Hartford, CT 06103www.wirereinforcementinstitute.org

8.2—Cited referencesAASHTO, 2002, “LRFD Bridge Design Specifications,”

second edition, American Association of State Highway andTransportation Officials, Washington, DC.

AASHTO, 2004, “Standard Specifications for HighwayBridges,” 22nd edition, American Association of StateHighway and Transportation Officials, Washington, DC.

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Amorn, W.; Bowers, J.; Girgas, A.; and Tadros, M. K.,2007, “Fatigue of Deformed Welded-Wire Reinforcement,”PCI Journal, V. 52, No. 1, Jan.-Feb. 2007, pp. 106-120.

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Crum, R. G., 1959, “Tensile Impact Tests for ConcreteReinforcing Steels,” ACI JOURNAL, Proceedings V. 56, No. 1,July, pp. 59-61.

Furlong, R.; Fenves, G.; and Kasl, E., 1991, “WeldedStructural Wire Reinforcement for Columns,” ACI StructuralJournal, V. 88, No. 5, Sept.-Oct., pp. 585-591.

Griezic, A.; Cook, W.; and Mitchell, D., 1994, “Tests toDetermine Performance of Deformed Welded Wire Stirrups,”ACI Structural Journal, V. 91, No. 2, Mar.-Apr., pp. 211-220.

Guimaraes, G. N.; Kreger, M. E.; and Jirsa, J. O., 1992,“Evaluation of Joint-Shear Provisions for Interior Beam-Column-Slab Connections Using High-Strength Materials,”ACI Structural Journal, V. 89, No. 1, Jan.-Feb., pp. 89-98.

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As ACI begins its second century of advancing concrete knowledge, its original chartered purposeremains “to provide a comradeship in finding the best ways to do concrete work of all kinds and inspreading knowledge.” In keeping with this purpose, ACI supports the following activities:

· Technical committees that produce consensus reports, guides, specifications, and codes.

· Spring and fall conventions to facilitate the work of its committees.

· Educational seminars that disseminate reliable information on concrete.

· Certification programs for personnel employed within the concrete industry.

· Student programs such as scholarships, internships, and competitions.

· Sponsoring and co-sponsoring international conferences and symposia.

· Formal coordination with several international concrete related societies.

· Periodicals: the ACI Structural Journal and the ACI Materials Journal, and Concrete International.

Benefits of membership include a subscription to Concrete International and to an ACI Journal. ACImembers receive discounts of up to 40% on all ACI products and services, including documents, seminarsand convention registration fees.

As a member of ACI, you join thousands of practitioners and professionals worldwide who share acommitment to maintain the highest industry standards for concrete technology, construction, andpractices. In addition, ACI chapters provide opportunities for interaction of professionals and practitionersat a local level.

American Concrete Institute38800 Country Club DriveFarmington Hills, MI 48331U.S.A.Phone: 248-848-3700Fax: 248-848-3701

www.concrete.org





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The AMERICAN CONCRETE INSTITUTE

was founded in 1904 as a nonprofit membership organization dedicated to publicservice and representing the user interest in the field of concrete. ACI gathers anddistributes information on the improvement of design, construction andmaintenance of concrete products and structures. The work of ACI is conducted byindividual ACI members and through volunteer committees composed of bothmembers and non-members.

The committees, as well as ACI as a whole, operate under a consensus format,which assures all participants the right to have their views considered. Committeeactivities include the development of building codes and specifications; analysis ofresearch and development results; presentation of construction and repairtechniques; and education.

Individuals interested in the activities of ACI are encouraged to become a member.There are no educational or employment requirements. ACI’s membership iscomposed of engineers, architects, scientists, contractors, educators, andrepresentatives from a variety of companies and organizations.

Members are encouraged to participate in committee activities that relate to theirspecific areas of interest. For more information, contact ACI.

www.concrete.org






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