Concrete Reinforcement
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 6
to Rev 7
in Concrete Reinforcement.
---
title: Concrete Reinforcement
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## Reinforcement shall be installed in strict accordance with the Contract Drawings, the Shop Drawings reviewed under this specification, and ACI SPEC-301-16, Specifications for Structural Concrete.
## Where these documents conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
−## This specification shall be read in conjunction with [[sync/cast-in-place-concrete]] for requirements governing the concrete itself. {note}
+## This specification shall be read in conjunction with [[sync/cast-in-place-concrete]] for requirements governing the concrete itself.
# Referenced Standards {toc}
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```
−### Contractor shall submit shop drawings and bar lists for review by the Engineer of Record before any reinforcement is fabricated or delivered to the project site.
### Shop drawings shall be prepared by a qualified detailer in accordance with the CRSI Manual of Standard Practice and shall show, for every concrete element, bar sizes, grades, coatings, lengths, bends, hook geometry, placement dimensions, bar spacing, concrete cover to each bar face, splice locations and lengths, mechanical coupler types and locations, lap zones, and bar support locations and types.
### Bar lists shall be keyed to the shop drawing mark system and shall state, for each bar mark, bar designation, grade, coating, quantity, length, bending details with critical dimensions flagged, and unit and total weight.
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```
−### Certified mill test reports (CMTRs) shall be submitted for every heat of steel used on the project.
### CMTRs shall show heat number, bar designation and grade, carbon equivalent (CE) for bars designated for welding, yield strength, tensile strength, elongation, and bend test results.
### CMTRs shall be submitted before the material they represent is incorporated into the work.
…12 unchanged lines
### Where special inspection of reinforcement is required by the locally adopted IBC and the project's Statement of Special Inspections, the Contractor shall coordinate the inspection program with the Special Inspector.
−### Where special inspection of reinforcement is required by the locally adopted IBC and the project's Statement of Special Inspections, the Contractor shall coordinate the inspection program with the Special Inspector.
### Special inspection submittals shall be made in accordance with the Statement of Special Inspections, not this specification section alone.
…8 unchanged lines
options:
- As-built markup drawings of field changes to reinforcement placement, splices, and cover
−default: [As-built markup drawings of field changes to reinforcement placement, splices, and cover]
+default:
+ - "As-built markup drawings of field changes to reinforcement placement, splices, and cover"
```
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```
−### Special inspection of reinforcing steel shall be performed in accordance with IBC Chapter 17, the locally adopted building code, and the project's Statement of Special Inspections.
### The type and frequency of special inspection shall be as indicated in the Statement of Special Inspections, which takes precedence over any conflicts with this specification.
### Special inspection shall include, at minimum, verification of bar grade and size against shop drawings, inspection of bar placement, cover, spacing, and lap lengths prior to concrete placement, and observation of mechanical splice installation.
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#### ASTM A615 is available in Grade 40, Grade 60, Grade 80, and Grade 100, with yield strengths of 40,000 psi, 60,000 psi, 80,000 psi, and 100,000 psi respectively. {note}
+#### Grade 60 is the predominant grade in current commercial construction and is the default for most elements unless the Contract Drawings specify otherwise.
+
```datasheet
label: Deformed Reinforcing Bar Grade — Primary Structural Elements
…8 unchanged lines
default: "Grade 60 (ASTM A615)"
```
−
−#### Grade 60 is the predominant grade in current commercial construction and is the default for most elements unless the Contract Drawings specify otherwise.
#### Where the Contract Drawings require Grade 80 or Grade 100 bars, those grades shall be furnished within the element and load-combination limits ACI 318-19 places on higher-strength grades.
#### Field welding of ASTM A615 bars shall require chemical analysis of each heat before welding to establish a preheat requirement per AWS D1.4.
…7 unchanged lines
#### ASTM A706 is available in Grade 60 and Grade 80. {note}
+#### For seismic force-resisting systems in Seismic Design Categories D, E, and F, longitudinal bars in special moment frames and special structural walls shall be ASTM A706 per ACI 318-19 Chapter 18 unless the Engineer of Record has specifically approved ASTM A615 based on project-specific testing.
+#### Where the Contract Drawings designate seismic application requirements, ASTM A706 bars shall be used unless the Contract Drawings explicitly permit ASTM A615.
+
```datasheet
label: ASTM A706 Weldable Bars Required
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```
−#### For seismic force-resisting systems in Seismic Design Categories D, E, and F, longitudinal bars in special moment frames and special structural walls shall be ASTM A706 per ACI 318-19 Chapter 18 unless the Engineer of Record has specifically approved ASTM A615 based on project-specific testing.
−#### Where the Contract Drawings designate seismic application requirements, ASTM A706 bars shall be used unless the Contract Drawings explicitly permit ASTM A615.
−
### ASTM A1035 High-Strength Bars {toc}
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### Reinforcing bars shall be furnished in standard ASTM bar designations from No. 3 through No. 18, as indicated on the Contract Drawings and shop drawings.
−### Bar designation numbers correspond to the nominal diameter in eighths of an inch: No. 3 = 3/8 in., No. 4 = 1/2 in., No. 5 = 5/8 in., and so on. {note}
```datasheet
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default: deferred
```
+### Bar designation numbers correspond to the nominal diameter in eighths of an inch: No. 3 = 3/8 in., No. 4 = 1/2 in., No. 5 = 5/8 in., and so on. {note}
−### Reinforcing bars shall be furnished in standard ASTM bar designations from No. 3 through No. 18, as indicated on the Contract Drawings and shop drawings.
### Bar sizes larger than No. 11 (1-3/8 in. nominal diameter) shall observe lap splicing restrictions, and ACI 318-19 prohibits lap splices for No. 14 and No. 18 bars except for specific conditions.
### Substitute bar sizes may be used only with written approval of the Engineer of Record and shall provide equivalent or greater cross-sectional area and equivalent or greater development capacity.
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#### The epoxy coating reduces chloride ion penetration to the bar surface and significantly extends time-to-corrosion in aggressive exposures. {note}
+#### Whether epoxy-coated reinforcement is required, and for which zones or elements, shall be specified based on the corrosion exposure of the concrete.
+
```datasheet
label: Epoxy-Coated Reinforcement Required
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#### Stainless steel bars are significantly more expensive than coated carbon-steel bars. {note}
+#### The use of stainless steel reinforcing bars shall be limited to elements and zones specifically designated on the Contract Drawings.
+
```datasheet
label: Stainless Steel Reinforcement Required
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```
−#### The use of stainless steel reinforcing bars shall be limited to elements and zones specifically designated on the Contract Drawings.
−
## Welded Wire Reinforcement {toc}
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# Fabrication {toc}
−## General Requirements {toc}
+## Reinforcing bars shall be fabricated in accordance with the reviewed shop drawings, the CRSI Manual of Standard Practice, and the applicable ASTM material specification.
+## Fabrication shall include all cutting to length, bending, assembly of reinforcement cages, and application of identification tags.
−### Reinforcing bars shall be fabricated in accordance with the reviewed shop drawings, the CRSI Manual of Standard Practice, and the applicable ASTM material specification.
−### Fabrication shall include all cutting to length, bending, assembly of reinforcement cages, and application of identification tags.
+## Bars shall be fabricated to the standard bending tolerances of the CRSI Manual of Standard Practice; dimensions flagged as "Critical" on the shop drawings shall be held to the tighter tolerances noted there.
+## Bars shall not be re-bent or straightened in a manner that damages the steel.
+## Cold-bending of bars in the field is permitted only for minor adjustments and shall not be done for No. 8 bars and larger without written approval of the Engineer of Record and compliance with ACI 318-19 Section 26.6.2.
−### Bars shall be fabricated to the standard bending tolerances of the CRSI Manual of Standard Practice; dimensions flagged as "Critical" on the shop drawings shall be held to the tighter tolerances noted there.
−### Bars shall not be re-bent or straightened in a manner that damages the steel.
−### Cold-bending of bars in the field is permitted only for minor adjustments and shall not be done for No. 8 bars and larger without written approval of the Engineer of Record and compliance with ACI 318-19 Section 26.6.2.
−
## Bending Requirements {toc}
### The minimum inside bend diameters for standard hooks are: No. 3 through No. 8 bars — 6db (where db is the nominal bar diameter); No. 9, 10, and 11 bars — 8db; No. 14 and 18 bars — 10db. {note}
+### All bars shall be cold-bent.
+### Hot bending is not permitted unless approved in writing by the Engineer of Record and accompanied by heat treatment to restore properties.
+### Standard hooks shall be formed to the minimum inside bend diameters specified in ACI 318-19 Table 25.3.1 and detailed in the CRSI Manual of Standard Practice.
+### Stirrups and ties shall follow the reduced bend diameter requirements of ACI 318-19 Table 25.3.2.
+
```datasheet
label: Stirrup and Tie Minimum Bend Diameter Compliance
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default: "Per ACI 318-19 Table 25.3.2 — confirmed by fabricator"
```
−
−### All bars shall be cold-bent.
−### Hot bending is not permitted unless approved in writing by the Engineer of Record and accompanied by heat treatment to restore properties.
−### Standard hooks shall be formed to the minimum inside bend diameters specified in ACI 318-19 Table 25.3.1 and detailed in the CRSI Manual of Standard Practice.
−### Stirrups and ties shall follow the reduced bend diameter requirements of ACI 318-19 Table 25.3.2.
### Bends of less than these minimum diameters crack the bar surface and damage the transverse deformations, reducing both tensile capacity and bond to concrete. {note}
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```
−### Bars shall be tied at intersections at sufficient spacing to hold all bars in their correct positions during concrete placement.
### All bar intersections at the perimeter of each mat or cage shall be tied.
### Interior intersections shall be tied at every other intersection in a checkerboard pattern, or at closer spacing as directed by the Engineer of Record or Special Inspector when the mat configuration or the vibration conditions require closer tying.
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### Cover requirements are specified in ACI 318-19 Table 20.6.1 and reflect both structural requirements (bond development length depends on cover) and durability requirements (cover is the primary barrier preventing chloride, carbonation, and moisture from reaching the steel). {note}
+### The minimum concrete cover requirements below apply unless the Contract Drawings specify greater cover, and greater cover than the tabulated minimum shall always govern.
+### For concrete cast against and permanently exposed to earth (footings, grade beams, pile caps cast against soil), minimum cover shall be 3 in.
+
```datasheet
label: Concrete Cover — Cast Against and Permanently in Contact with Ground
…7 unchanged lines
default: "3 in. (ACI 318-19 minimum)"
```
+### For concrete exposed to earth or weather (garage decks, exterior slabs, surfaces in regular contact with moisture or freezing-and-thawing), minimum cover shall be 2 in. for No. 6 through No. 18 bars and 1-1/2 in. for No. 5 bars and smaller.
```datasheet
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default: "1-1/2 in. (ACI 318-19 minimum)"
```
+### For concrete not exposed to weather or in contact with ground, primary reinforcement in beams, girders, and columns shall have 1-1/2 in. minimum cover.
```datasheet
…7 unchanged lines
default: "1-1/2 in. (ACI 318-19 minimum)"
```
+### For slabs, walls, and joists not exposed to weather or in contact with ground, minimum cover shall be 3/4 in. for No. 5 bars and smaller and 1-1/2 in. for No. 6 through No. 11 bars.
```datasheet
…8 unchanged lines
default: "3/4 in. (ACI 318-19 minimum)"
```
−
−### The minimum concrete cover requirements below apply unless the Contract Drawings specify greater cover, and greater cover than the tabulated minimum shall always govern.
−### For concrete cast against and permanently exposed to earth (footings, grade beams, pile caps cast against soil), minimum cover shall be 3 in.
−### For concrete exposed to earth or weather (garage decks, exterior slabs, surfaces in regular contact with moisture or freezing-and-thawing), minimum cover shall be 2 in. for No. 6 through No. 18 bars and 1-1/2 in. for No. 5 bars and smaller.
−### For concrete not exposed to weather or in contact with ground, primary reinforcement in beams, girders, and columns shall have 1-1/2 in. minimum cover.
−### For slabs, walls, and joists not exposed to weather or in contact with ground, minimum cover shall be 3/4 in. for No. 5 bars and smaller and 1-1/2 in. for No. 6 through No. 11 bars.
### The Engineer of Record shall specify greater cover on the Contract Drawings for elements in high-chloride environments, for elements with large aggregates, for fire-resistance requirements beyond code minimum, or where any other condition warrants increased protection.
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# Splices and Couplers {toc}
−## General Requirements {toc}
+## Splices are necessary whenever bar lengths exceed available mill lengths (typically 60 ft), where construction joints require transition between elements, and where bar congestion or structural analysis requires staged termination of bars. {note}
−### Splices are necessary whenever bar lengths exceed available mill lengths (typically 60 ft), where construction joints require transition between elements, and where bar congestion or structural analysis requires staged termination of bars. {note}
+## Splices shall be designed and located by the Engineer of Record.
+## The Contractor shall not relocate or add splices without written approval from the Engineer of Record.
+## Every splice shall either develop the full tensile capacity of the bars being spliced (Type 2 performance, required in ductile seismic zones and frequently specified for critical structural elements) or develop at least 125 percent of the specified yield strength of the bars (Type 1 performance, the code minimum for most non-seismic applications).
+## The Contract Drawings shall designate which type of performance is required for each splice location.
−### Splices shall be designed and located by the Engineer of Record.
−### The Contractor shall not relocate or add splices without written approval from the Engineer of Record.
−### Every splice shall either develop the full tensile capacity of the bars being spliced (Type 2 performance, required in ductile seismic zones and frequently specified for critical structural elements) or develop at least 125 percent of the specified yield strength of the bars (Type 1 performance, the code minimum for most non-seismic applications).
−### The Contract Drawings shall designate which type of performance is required for each splice location.
−
## Tension Lap Splices {toc}
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```
−### Only bars verified as weldable shall be field-welded.
### ASTM A706 bars are weldable by specification and may be welded without chemical analysis.
### ASTM A615 bars shall require carbon equivalent testing of each heat before welding to determine preheat requirements per AWS D1.4.
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### The following apply to nonprestressed reinforcement. {note}
+### For effective depth (d) and clear cover to formed surfaces, the tolerance shall be ±3/8 in. where d ≤ 8 in., ±1/2 in. where d > 8 in. and ≤ 24 in., and ±1 in. where d > 24 in., applied to the position of the bar measured from the relevant reference face.
+### The reduction in concrete cover shall not exceed one-third of the specified concrete cover, and the reduction in cover to formed soffits shall not exceed 1/4 in., per ACI 117.
+
```datasheet
label: Cover Reduction Tolerance — Maximum Allowable
…4 unchanged lines
default: "Per ACI 117: not to exceed 1/3 specified cover, and no more than 1/4 in. for formed soffits"
```
−
−### For effective depth (d) and clear cover to formed surfaces, the tolerance shall be ±3/8 in. where d ≤ 8 in., ±1/2 in. where d > 8 in. and ≤ 24 in., and ±1 in. where d > 24 in., applied to the position of the bar measured from the relevant reference face.
−### The reduction in concrete cover shall not exceed one-third of the specified concrete cover, and the reduction in cover to formed soffits shall not exceed 1/4 in., per ACI 117.
### The longitudinal position of bends and bar ends shall be within ±2 in. except at discontinuous ends where the tolerance is ±1/2 in.
### Spacing between bars shall be within ±1/4 in. for bars at 12 in. on center or less and ±1/2 in. for bars at more than 12 in. on center.
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### Material warranties provided by the bar manufacturer or the coating applicator shall be passed through to the Owner.
### For epoxy-coated bars, the coater's warranty against coating delamination (where provided) shall be documented and included in the closeout submittals.