ACI 318 Codes
3.5.3.5
Welded plain wire fabric for concrete reinforcement
3.5.3.6
Welded deformed wire for concrete reinforcement
7.2
Minimum Bend Diameters
7.5
Placing Reinforcement
7.6.5
Walls and slabs
7.12.2.1
Area of shrinkage and temperature reinforcement
12.2
Development of deformed bars and deformed wire in tension
12.3
Development of deformed bars and deformed wire in compression
12.15
Splices of deformed bars and deformed wire in tension
12.7
Development of Welded Deformed Wire Fabric in Tension
12.8
Development of Welded Plain Wire Fabric in Tension
12.18
Splices of Welded Deformed Wire Fabric in Tension
12.19
Splices of Welded Plain Wire Fabric in Tension
14.3.2
Minimum ratio of vertical reinforcement
14.3.3
Minimum ratio of horizontal reinforcement
ASTM Standard
A82
Standard Specification for Steel Wire
A185
Standard Specification for Steel welded Wire Fabric, Plain, for Concrete Reinforcement
A496
Standard Specification for Steel Wire, Deformed, for Concrete Reinforcement
A497
Standard Specification for Steel Welded Wire Fabric, Deformed, for Concrete Reinforcement
A884
Standard Specification for Epoxy-Coated Steel Wire and Welded Wire Fabric for Reinforcement
IBC Codes
1901.2
Plain and reinforced concrete
1901.3
Source and applicability
1901.4
Construction documents
1903.5
Steel reinforcement
1903.5.1
Reinforcement type
1907.5.3
Welded wire fabric

3.5.3.5 - Welded plain wire fabric for concrete reinforcement

3.5.3.5 - Welded plain wire fabric for concrete reinforcement shall conform to "Specification for Steel Welded Wire Fabric, Plain, for Concrete Reinforcement" (ASTM A 185), except that for wire with a specified yield strength fy exceeding 60,000 psi, fy shall be the stress corresponding to a strain of 0.35 percent if the yield strength specified in the design exceeds 60,000 psi. Welded intersections shall not be spaced farther apart than 12 in. in direction of calculated stress, except for wire fabric used as stirrups in accordance with 12.13.2.
↑ back to top

3.5.3.6 - Welded deformed wire fabric for concrete reinforcement

3.5.3.6 - Welded deformed wire fabric for concrete reinforcement shall conform to "Specification for Steel Welded Wire Fabric, Deformed, for Concrete Reinforcement" (ASTM A 497), except that for wire with a specified yield strength fy exceeding 60,000 psi, fy shall be the stress corresponding to a strain of 0.35 percent if the yield strength specified in the design exceeds 60,000 psi. Welded intersections shall not be spaced farther apart than 16 in. in direction of calculated stress, except for wire fabric used as stirrups in accordance with 12.13.2.
↑ back to top

7.2- Minimum bend diameters

7.2.1- Diameter of bend measured on the inside of the bar, other than for stirrups and ties in sizes No.3 through No.5, shall not be less than the values in Table7.2.
7.2.2 - Inside diameter of bend for stirrups and ties shall not be less than 4db for No.5 bar and smaller. For bars larger than No.5, diameter of bend shall be in accordance with Table 7.2.
7.2.3 - Inside diameter of bend in welded wire fabric (plain or deformed) for stirrups and ties shall not be less than 4db for deformed wire larger than 06 and 2db for all other wires. Bends with inside diameter of less than 8db shall not be less than 4db from nearest welded intersection.
↑ back to top

7.5- Placing reinforcement

7.5- Placing reinforcement
7.5.1 - Reinforcement, including tendons, and post-tensioning ducts shall be accurately placed and adequately supported before concrete is placed, and shall be secured against displacement within tolerances permitted in 7.5.2.
7.5.2 - Unless otherwise specified by the registered design professional, reinforcement, including tendons, and post-tensioning ducts shall be placed within the tolerances in 7.5.2.1 and 7.5.2.2<./div>
7.5.2.1 - Tolerance for depth d, and minimum concrete cover in flexural members, walls and compression members shall be as follows: except that tolerance for the clear distance to formed soffits shall be minus 1/4 in. and tolerance for cover shall not exceed minus 1/3 the minimum concrete cover required in the design drawings or specifications.
7.5.2.2 - Tolerance for longitudinal location of bends and ends of reinforcement shall be +- 2 in., except the tolerance shall be +- 1/2 in. at the discontinuous ends of brackets and corbels, and +- 1 in. at the discontinuous ends of other members. The tolerance for minimum concrete cover of 7.5.2.1 shall also apply at discontinuous ends of members.
7.5.3 - Welded wire fabric (with wire size not greater than W5 or 05) used in slabs not exceeding 10ft in span shall be permitted to be curved from a point near the top of slab over the support to a point near the bottom of slab at midspan, provided such reinforcement is either continuous over, or securely anchored at support.
7.5.4 – Welding of crossing bars shall not be permitted for assembly of reinforcement unless authorized by the engineer.

7.6.5 - Walls and slab

7.6.5 - In walls and slabs other than concrete joist construction, primary flexural reinforcement shall not be spaced farther apart than three times the wall or slab thickness, nor farther apart than 18 in.
↑ back to top

7.12.2.1 - Area of shrinkage and temperature reinforcement

7.12.2.1 - Area of shrinkage and temperature reinforcement shall provide at least the following ratios of reinforcement area to gross concrete area, but not less than 0.0014:

(a) Slabs where Grade 40 or 50 deformed bars are used 0.0020
(b) Slabs where Grade 60 deformed bars or welded wire fabric (plain or deformed) are used 0.0018
(c) Slabs where reinforcement with yield stress exceeding 60,000 psi measured at a yield strain of 0.35 percent is used (0.0018 x 60,000) / fy
↑ back to top

12.2 - Development of deformed bars and deformed wire in tension

12.2.1 - The general development length equation (Eq. (12-1)) is given in 12.2.3. The equation is based on the expression for development length previously endorsed by Committee 408. 12.2,12.3 In Eq. (12-1), c is a factor that represents the smallest of the side cover, the cover over the bar or wire (in both cases measured to center of the bar or wire), or one-half the center-to-center spacing of the bars or wires. Ktr is a factor that represents the contribution of confining reinforcement across potential splitting planes. a is the traditional reinforcement location factor to reflect the adverse effects of the top reinforcement casting position.b is a coating factor reflection the effects of epoxy coating. There is a limit on the product ab, g is a reinforcement size factor that reflects the more favorable performance of smaller diameter reinforcement. l is a factor reflecting the lower tensile strength of lightweight concrete and the resulting reduction of the splitting resistance, which increase the development length in lightweight concrete. A limit of 2.5 is placed on the term (c + Ktr)/db. When (c + Ktr)/db is less than 2.5, splitting failures are likely to occur. For values above 2.5, a pullout failure is expected and increased in cover or transverse reinforcement is unlikely to increase the anchorage capacity.

12.2.2 - For deformed bars or deformed wire ld shall be as follows:

12.2.3 - For deformed bars or deformed wire ld shall be:

in which the term (c + Ktr)/db shall not be taken greater than 2.5

12.2.4 - The factors for use in the expression for development of deformed bars and deformed wire in tension in Chapter 12 are as follows:

a = reinforcement location factor
Horizontal reinforcement so placed that more than 12 in of fresh concrete is cast in the member below the development length or splice .................................. 1.3
Other reinforcement ................................................................................. 1.0

b = coating factor
Epoxy-coated bars or wires with cover less than 3db,
or clear spacing less than 6db ................................................................... 1.5

However, the product ab need not be taken greater than 1.7

g = reinforcement size factor
No. 6 and smaller bars and deformed wires .............................................. 0.8
No. 7 and larger bars ............................................................................... 1.0

l = lightweight aggregate concrete factor
When lightweight aggregate concrete is used ............................................. 1.3
However, when fct is specified, l shall be permitted to be taken as
6.7 sqrt (fc'/fct) but not less than ............................................................. 1.0
When normalweight concrete is used ......................................................... 1.0

c = spacing or cover dimension, in.
Use the smaller of either the distance from the center of the bar or wire to the nearest concrete surface or one-half the center-to-center spacing of the bars or wires being developed.

             Ktr = transverse reinforcement index
                   = Atrfyt
                      1500 sn
It shall be permitted to use Ktr = 0 as a design simplification even if transverse reinforcement is present.

12.2.5 - Excess reinforcement
Reduction in development length shall be permitted where reinforcement in a flexural member
is in excess of that required by analysis except where anchorage or development for fy
is specifically required or the reinforcement is designed
under provisions of 21.2.1.4 ........................................... (As required)/(As Provided)

↑ back to top

12.3 - Development of deformed bars and deformed wire in compression

12.3.1 - Development length ldc, in inches, for deformed bars and deformed wire in compression shall be determined from 12.3.2 and applicable modification factors of 12.3.3 but ldc shall not be less than 8 in.

12.3.2 - For deformed bars and deformed wire, ldc shall be taken
as the larger of (0.02fy/ sqrt.(fc'))db and (0.0003fy)db, where the constant 0.0003 carries the unit of in. 2/lb

12.3.3 - The length ldc in 12.3.2 shall be permitted to be multiplied by the applicable factors for:

(a) Reinforcement in excess of that required by analysis.(As required)/(As provided)
(b) Reinforcement enclosed within spiral reinforcement not less than 1/4 in. diameter and not more than 4 in. pitch or within No. 4 ties in conformance with 7.10.5 and spaced at not more than 4 in. on center ................................................ 0.75

↑ back to top

12.15 - Splices of deformed bars and deformed wire in tension

12.15.1 - Lap splices in tension are classified as Type A or B, with length of lap a multiple of the tensile development length ld. The development length ld used to obtain lap length should be based on fy because the splice classifications already reflect any excess reinforcement at the splice location; therefore, the factor of 12.2.5 for excess As should not be used. When multiple bars located in the same place are spliced at the same section, the clear spacing is the minimum clear distance between the adjacent splices. For splices in columns with offset bars, Fig. R12.15.1 (a) illustrates the clear spacing to be used. For staggered splices, the clear spacing is the minimum distance between adjacent splices [distance x Fig. R12.15.1 (b)].

12.15.2 - Lap splices of deformed bars and deformed wire in tension shall be Class B splices except that Class A splices are allowed when:

(a) the area of reinforcement provided is least twice that required by analysis over the entire length of the splice; and

(b) one-half or less of the total reinforcement is spliced within the required lap length.

12.15.3 - Mechanical or welded splices used where area of reinforcement provided is less than twice that required by analysis shall meet requirements of 12.14.3.2 or 12.14.3.4

12.15.4 - Mechanical or welded splices not meeting the requirements of 12.14.3.2 or 12.14.3.4 shall be permitted for No. 5 bars and smaller if the requirement of 12.15.4.1 through 12.15.4.3 are met:

12.15.4.1 - Splices shall be staggered at least 24 in.

12.15.4.2 - In computing the tensile forces that can be developed at each section, the spliced reinforcement stress shall be taken as the specified splice strength, but not greater than fy. The stress in the unspliced reinforcement shall be taken as fy times the ratio of the shortest length embedded beyond the section to ld, but not greater than fy.

12.15.4.3 - The total tensile force that can be developed at each section must be least twice that required by analysis, and at least 20,000 psi time the total area of reinforcement provided.

12.15.5 - Splices in tension tie members shall be made with a full mechanical or full welded splice in accordance with 12.14.3.2 or 12.14.3.4 and splices in adjacent bars shall be staggered at least 30 in.

↑ back to top

12.7 - Development of welded deformed wire fabric in tension

12.7 - Development of welded deformed wire fabric in tension

12.7.1 - Development length ld, in inches, of welded deformed wire fabric measured from the point of critical section to the end of wire shall be computed as the product of the development length ld, from 12.2.2 or 12.2.3 times a wire fabric factor from 12.7.2 or 12.7.3. It shall be permitted to reduce the development length in accordance with 12.2.5when applicable, but ld shall not be less than 8 in. except in computation of lap splices by 12.18. When using the wire fabric factor from 12.7.2, it shall be permitted to use an epoxy-coating factor p of 1.0 for epoxy-coated welded wire fabric in 12.2.2 and 12.2.3.

12.7.2 - For welded deformed wire fabric with at least one cross wire within the development length and not less than 2 in. from the point of the critical section, the wire fabric factor shall be the greater of:

but need not be greater than 1.

12.7.3 - For welded deformed wire fabric with no cross wires within the development length or with a single cross wire less than 2 in. from the point of the critical section, the wire fabric factor shall be taken as 1, and the development length shall be determined as for deformed wire.

12.7.4-When any plain wires are present in the deformed wire fabric in the direction of the development length, the fabric shall be developed in accordance with 12.8.

↑ back to top

12.8-Development of welded plain wire fabric in tension

12.8-Development of welded plain wire fabric in tension

Yield strength of welded plain wire fabric shall be considered developed by embedment of two cross wires with the closer cross wire not less than 2 in. from the point of the critical section. However, the development length td in inches, measured from the point of the critical section to the outermost cross wire shall not be less than

except that when reinforcement provided is in excess of that required, this length may be reduced in accordance with 12.2.5. ld shall not be less than 6 in. except in computation of lap splices by 12.19.

↑ back to top

12.18 - Splices of welded deformed wire fabric in tension

12.18 - Splices of welded deformed wire fabric in tension 12.18.1 - Minimum length of lap for lap splices of welded deformed wire fabric measured between the ends of each fabric sheet shall be not less than 1.3 ld nor 8 in., and the overlap measured between outermost cross wires of each fabric sheet shall be not less than 2 in. ld shall be the development length for the specified yield strength fy in accordance with 12.7. 12.18.2 - Lap splices of welded deformed wire fabric, with no cross wires within the lap splice length, shall be determined as for deformed wire. 12.18.3-When any plain wires are present in the deformed wire fabric in the direction of the lap splice or when deformed wire fabric is lap spliced to plain wire fabric, the fabric shall be lap spliced in accordance with 12.19.
↑ back to top

12.19 - Splices of welded plain wire fabric in tension

Minimum length of lap for lap splices of welded plain wire fabric shall be in accordance with 12.19.1 and 12.19.2. 12.19.1 - When area of reinforcement provided is less than twice that required by analysis at splice location, length of overlap measured between outermost cross wires of each fabric sheet shall be not less than one spacing of cross wires plus 2 in., nor less than 1.5 ld, nor 6 in. The development length ld for the specified yield strength fy shall be in accordance with 12.8. 12.19.2 - When area of reinforcement provided is at least twice that required by analysis at splice location, length of overlap measured between outermost cross wires of each fabric sheet shall not be less than 1.5 ld, nor 2 in. ld shall be the development length for the specified yield strength fy in accordance with 12.8.
↑ back to top

14.3.2 - Minimum ratio of vertical reinforcement

14.3.2 - Minimum ratio of vertical reinforcement area to gross concrete area shall be:

(a) 0.0012 for deformed bars not larger than No. 5 with a specified yield strength not less than 60,000 psi; or

(b) 0.0015 for other deformed bars; or

(c) 0.0012 for welded wire fabric (plain or deformed) not larger than W31 or D31.

↑ back to top

14.3.3 - Minimum ratio of horizontal reinforcement

14.3.3 - Minimum ratio of horizontal reinforcement are to gross concrete area shall be:

(a) 0.0020 for deformed bars not larger than No. 5 with a specified yield strength not less than 60,000 psi; or

(b) 0.0025 for other deformed bars; or

(c) 0.0020 for welded wire fabric (plain or deformed) not larger than W31 or D31.

↑ back to top

ASTM A82 Standard Specification for Steel Wire, Plain, for Concrete Reinforcement

Developed by Subcommittee: A01.05
Year: 01
Pages: 4

Scope:
 

1.1 This specification covers cold-drawn steel wire, as-drawn or galvanized, to be used as such, or in fabricated form, for the reinforcement of concrete, in sizes not less than 2.03 mm (0.080 in.) nominal diameter.

1.2 Supplement S1 describes high-strength wire, which shall be furnished when specifically ordered. It shall be permissible to furnish high-strength wire in place of regular wire if mutually agreed to by the purchaser and the supplier.

1.3 The values stated in either inch-pound units or SI units are to be regarded as standard. Within the text the inch-pound units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values may result in nonconformance with the specification.

 
↑ back to top

ASTM A185 Standard Specification for Steel Welded Wire Reinforcement, Plain, for Concrete

Developed by Subcommittee: A01.05
Year: 01
Pages: 5

Scope:
 

1.1 This specification covers welded wire reinforcement to be used for the reinforcement of concrete.

Note 1-Welded wire for concrete reinforcement has been described by various terms: welded wire fabric, WWF, fabric, and mesh. The wire reinforcement industry prefers the term "welded wire reinforcement" (WWR) as being more representative of the range of products being manufactured. Therefore, the term "welded wire fabric" has been replaced with the term "welded wire reinforcement" in this specification and in related specifications.

1.2 The values stated in inch-pound or SI units are to be regarded as standard. Within the text the inch-pound units are shown in parenthesis. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values may result in nonconformance with the specification.

 
↑ back to top

ASTM A496 Standard Specification for Steel Wire, Deformed, for Concrete Reinforcement

Developed by Subcommittee: A01.05
Year: 01
Pages: 5

Scope:
 

1.1 This specification covers deformed steel wire which has been cold-worked by drawing, rolling, or both drawing and rolling, to be used as produced, or in fabricated form, for the reinforcement of concrete in sizes having nominal cross-sectional areas not less than 6.45 mm 2 (0.01 in.2).

1.2 Supplement S1 describes high-strength wire, which shall be furnished when specifically ordered. It shall be permissible to furnish high-strength wire in place of regular wire if mutually agreed to by the purchaser and supplier.

1.3 The values stated in either inch-pound units or SI units are to be regarded as standard. Within the text the inch-pound units are shown in brackets. The value stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values may result in nonconformance with the specification.

 
↑ back to top

ASTM A497 Standard Specification for Steel Welded Wire Reinforcement, Deformed, for Concrete

Developed by Subcommittee: A01.05
Year: 01
Pages: 5

Scope:

1.1 This specification covers welded wire reinforcement made from cold-worked drawn or rolled deformed wire, or a combination of deformed and non-deformed wires, to be used for the reinforcement of concrete.

Note 1-Welded wire for concrete reinforcement has been described by various terms: welded wire fabric, WWF, fabric, and mesh. The wire reinforcement industry prefers the term "welded wire reinforcement" (WWF) as being more representative of the range of products being manufactured. Therefore, the term "welded wire fabric" has been replaced with the term "welded wire reinforcement" in this specification and in other related specifications.

1.2 The values stated in either inch-pound or SI units are to be regarded as the standard. Within the text the inch-pound units are shown in parenthesis. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values may result in nonconformance with the specification.

↑ back to top

ASTM A884/A884M Standard Specification for Epoxy-Coated Steel Wire and Welded Wire Fabric for Reinforcement

Developed by Subcommittee: A01.05
Year: 01
Pages: 6

Scope:

1.1 This specification covers plain and deformed steel wire and plain and deformed steel welded wire fabric with protective epoxy coating. A Class A minimum coating thickness is required for wire and welded wire fabric intended for use as reinforcement in concrete and masonry. A Class B minimum coating thickness is required for wire and welded wire fabric intended for use as reinforcement in earth. A Type 1 coating is a fusion-bonded epoxy coating that has been designed to be sufficiently flexible to allow fabrication of the coated wire or welded wire fabric. A Type 2 coating is a fusion-bonded epoxy coating that has not been designed to be sufficiently flexible to allow fabrication of the coated wire or welded wire fabric.

Note 1--The coating applicator is identified throughout this specification as the manufacturer.

1.2 Other organic coatings may be used provided they meet the requirements of this specification.

1.3 This specification is applicable for orders in either SI units (Specification A884M) or in inch-pound units [Specification A884].

1.4 The values stated in either SI or inch-pound units are to be regarded as standard. Within the text, the inch-pound 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 except as specifically noted in . Combining values from the two systems may result in nonconformance with this specification.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

↑ back to top

1901.2 - Plain and reinforced concrete

Structural concrete shall be designed and constructed in accordance with the requirements of this chapter and ACI 318 as amended in Section 1908 of this code. Except for the provisions of Section 1904 and 1911, the design and construction of slabs on grade shall not be governed by this chapter unless they transmit vertical loads or lateral forces from other parts of the structure to the soil.
↑ back to top

1901.3 - Source and applicability

The contents of Sections 1902 through 1907 of this chapter are patterned after, and in general conformity with, the provisions for structural concrete in ACI 318. Where sections within Chapters 2 through 7 of ACI 318 are referenced in other chapters and appendices of ACI 318, the provisions of Sections 1902 through 1907 of this code shall apply.
↑ back to top

1901.4 - Construction documents

The construction documents for structural concrete construction shall include:

↑ back to top

1903.5 - Steel reinforcement

Reinforcement and welding of reinforcement to be placed in concrete construction shall conform to the requirements of this section.
↑ back to top

1903.5.1 - Reinforcement type

Reinforcement shall be deformed reinforcement, except plain reinforcement is permitted for spiral or prestressing steel, and reinforcement consisting of structural steel, steel pipe or steel tubing is permitted where specified in ACI 318. Reinforcement shall comply with ACI 318, Section 3.5
↑ back to top

1907.5.3 - Welded wire fabric

Welded wire fabric with wire size not greater than W5 or D5 used in slabs not exceeding 10 feet (3048 mm) in span is permitted to be curved from a point near the top of the slab over the support to a point near the bottom of the slab at midspan, provided such reinforcement is either continuous over, or securely anchored at support.
↑ back to top