489and prestressing steel embedded in units, including dowels in place and bearing pads or bearing devic - es; post-tensioning fittings, strands, and rods, grouting, joint fillers and sealers, waterproofing applied to structural units at the prestressing plant; testing and documentation, hauling, handling, storage, and treatment. Payment will be made under: ————————————————————————————Pay Item Pay Unit————————————————————————————Prestressed concrete (Shape, beam, Each description of cross section, and length) Prestressed concrete slab (Width, depth, and length) Each———————————————————————————— SECTION 406—REINFORCING STEEL
406.01 Description
This work shall consist of furnishing; coating, if required, and placing reinforcing steel or wire mesh used in concrete operations, except prestressed strands and wires, in accordance with these specifications and in conformity to the lines and details shown on the plans.
406.02 Materials
a.Steel used for reinforcement shall conform to Section 223. Except for spiral bars, bars more than 1/4 inch in diameter shall be deformed bars.
b.Welded wire fabric shall conform to Section 223.
c.Bar mat reinforcement shall conform to Section 223.
d.Corrosion resistant steel used for reinforcement shall conform to Section 223.
406.03 Procedures
a.Order Lists and Bending Diagrams: Copies of order lists and bending diagrams shall be furnished to the Engineer when required or requested.
b.Protecting Material: Reinforcing steel shall be stored on platforms, skids, or other supports that will keep the steel above ground, well drained, and protected against deformation. When placed in the work, steel reinforcement shall be free from dirt, paint, oil, or other foreign substances. Steel reinforcement with rust or mill scale will be permitted provided samples wire brushed by hand conform to the requirements for weight and height of deformation.
c.Fabrication: Bent bar reinforcement shall be cold bent to the shape shown on the plans. Fab- rication shall be in accordance with the ACI Detailing Manual – 2004 (SP-66-04).406.03 490Spiral bars shall be fabricated to have the proper diameter when placed in position at the pitch shown on the plans. Each end of a spiral bar shall have 1 1/2 finishing turns in a plane perpendicular to the axis of the spiral.
d.Placing and Fastening: Steel reinforcement shall be firmly held during the placing and setting of concrete. Bars, except those to be placed in vertical mats, shall be tied at every intersection where the spacing is more than 12 inches in any direction. Bars in vertical mats and in other mats where the spacing is 12 inches or less in each direction shall be tied at every intersection or at alternate in - tersections provided such alternate ties will accurately maintain the position of steel reinforcement during the placing and setting of concrete. Placing reinforcing steel in concrete after concrete has been freshly placed is not permitted. Unless otherwise specified by the Engineer, tie wires used with corrosion resistant reinforcing steel can be: plastic; solid stainless; epoxy-coated carbon (black) steel wire; or plastic-coated carbon (black) steel wire. The minimum clear distance from the face of the concrete to any reinforcing bar shall be maintained as specified in the table below. Location Minimum Cover (in) Normal Corrosive Marine2 Condition Environment1 Pier caps, bridge seats and backwalls: Principal reinforcement 2-3/4 3-3/4 4 Stirrups and ties 2-1/4 3-1/4 3-1/2 Pier caps, bridge seats and backwalls: (at open joint locations) Principal reinforcement 3-3/4 3-3/4 4 Stirrups and ties 3-1/4 3-1/4 3-1/2 Footings and pier columns: Principal reinforcement 3 4 4 Stirrups and ties 2-1/2 3-1/2 3-1/2 Cast-in-place deck slabs: Top reinforcement3 2-1/2 2-1/2 2-1/2 Bottom reinforcement 1-1/4 1-1/4 2 Precast and cast-in-place slab spans: Top reinforcement3 2-1/2 2-1/2 2-1/2 Bottom reinforcement 2 2 3 Prestressed slabs and box beams: Top steel 1-3/4 1-3/4 1-3/4 Stirrups and ties 1-1/8 1-1/8 1-1/8 Reinforcement concrete box culverts and rigid frames with more than 2 ft. fill over top of slab: Top slab – top reinforcement 1-1/2 2-1/2 3 Top slab – bottom reinforcement 1-1/2 2-1/2 3 Inside walls and bottom slab top mat 1-1/2 2-1/2 3 Outside walls and bottom slab bottom mat 1-1/2 2-1/2 3406.03 491Location Minimum Cover (in) Normal Corrosive Marine2 Condition Environment1 Reinforcement concrete box culverts and rigid frames with less than 2 ft. fill over top of slab: Top slab – top reinforcement 2-1/2 2-1/2 3 Top slab – bottom reinforcement 2 2-1/2 3 Inside walls and bottom slab top mat 1-1/2 2-1/2 3 Outside walls and bottom slab bottom mat 1-1/2 2-1/2 3 Rails, rail posts, curbs and parapets: Principal reinforcement 1-1/2 1-1/2 1-1/2 Stirrups and ties 1 1 1 Concrete piles cast against or permanently exposed to earth (not applicable for prestressed concrete): 3 3 3 Drilled shafts: Principle reinforcement 4 5 5 Ties and spirals 3-1/2 4-1/2 4-1/2 All other components not indicated above: Principle reinforcement 2-1/2 3-1/2 3-1/2 Stirrups and ties 2 3 3 1Corrosive environment affects cover where concrete surface is in permanent contact with corrosive soil. 2Marine includes all locations with direct exposure to brackish and salt water. 3Includes 1/2 inch monolithic (integral) wearing surface. Bars that must be positioned by maintaining clearances from more than one face shall be centered so that clearances indicated by the plan dimension of bars are equalized. Bars shall be placed so that the concrete cover as indicated on the plans will be maintained within a tolerance of 0 to +1/2 inch in the finally cast concrete. Where anchor bolts interfere with reinforcing steel, the steel position shall be adjusted without cutting to permit placing anchors in their proper locations. Plastic (composite) chairs may be used to support Corrosion Resistant Reinforcement (CRR) in precast concrete elements; otherwise, CRR in structures shall be supported by steel bar supports as follows, unless otherwise specified by the Engineer:
1.For Class I CRR, steel bar supports shall be: plastic-protected wire bar supports (per CRSI Class 1 – Maximum Protection) when stay-in-place forms are not used and the steel bar support will be exposed; and epoxy-coated bright basic wire bar supports (per CRSI Class 1A – Maximum Protection) when either stay-in-place forms are used or the steel bar support will not be exposed.
2.For Class II and Class III CRR, steel bar supports shall be: either stainless steel wire bar supports or plastic-protected wire bar supports (per CRSI Class 1 – Maximum Protection) when stay-in-place forms are not used and the steel bar support will be exposed; and 406.03 492epoxy-coated bright basic wire bar supports (per CRSI Class 1A – Maximum Protection) when either stay-in-place forms are used or the steel bar support will not be exposed.
3.Steel bar supports for CRR shall be fabricated from cold-drawn carbon steel wire conforming to the CRSI corrosion protection class listed above for their specific use, except for plastic- protected wire bar supports, which shall be epoxy-coated with plastic protection applied by dipping legs (i.e., capping legs with premolded plastic tips is prohibited). Carbon (black) steel in structures shall be supported by bright basic wire bar supports (per CRSI Class 3 – No Protection), except when cast-in-place members are cast directly on soil or rock, such as footings and approach slabs. In these cases, precast concrete supports and plastic (composite) chairs may be used. Steel bar supports for carbon (black) steel shall be fabricated from cold-drawn carbon steel wire. Precast concrete bar supports shall have a 28-day design compressive strength of at least 4,500 pounds per square inch and shall be furnished with plastic ties or shaped to prevent slippage from beneath the reinforcing bar. Side form spacers shall meet the same corrosion protection level as the bar supports. Bar supports for CRR in bridge decks and slab spans shall be spaced as recommended by CRSI but not more than 4 feet apart transversely or longitudinally. The mat of steel reinforcement closest to the surface shall be supported by bolster supports or individual chair bar supports and intermediate and upper mats can be supported by individual high chair bar supports or continuous bar supports placed between mats. When the upper mat is supported by the bottom mat (e.g., using continuous bar supports placed between mats), all the bar supports shall be spaced as recommended by CRSI but not more than 3 feet apart transversely or longitudinally. Bar supports shall be firmly stabilized so as not to displace under construction activities. Standees (a bar bent to a U-shape with 90 degree bent legs extending in opposite directions at right angles to the U-bend acting as a high chair resting on a lower mat of reinforcing bars to support an upper mat) may be used on simple slab spans provided they hold the reinforcing steel to the requirements specified herein and are firmly tied to the lower mat to prevent slippage. The use of standees will not be permitted for the top mat of steel on any continuous slab spans. In reinforced concrete sections or elements other than bridge decks and slab spans, the specified clear distance from the face of concrete to any reinforcing bar and the specified spacing between bars shall be maintained by means of approved types of stays, ties, hangers, or other supports adhering to the CRSI corrosion protection classes and specific uses listed above. The use of pieces of gravel, stone, brick, concrete, metal pipe, or wooden blocks will not be permitted as supports or spacers for reinforcing steel. The clear distance between bars shall be at least 1 1/2 times the specified maximum size of coarse aggregate but not less than 1 1/2 inches. Before concrete is placed, the Engineer will inspect reinforcing steel and deter - mine approval for proper position and the adequacy of the method for maintaining position.
e.Splicing and Lapping: Reinforcement shall be furnished in full lengths as indicated on the plans. Except where shown on the plans, splicing bars will not be permitted without the written approval of the Engineer. Splices shall be as far apart as possible. In lapped splices, bars shall be placed in contact and wired together. Lap lengths shall be as indicated on the plans. When reinforcing bars cannot be fabricated with the lengths shown on the plans, the bars may be lapped at no additional cost to the Department. Lap lengths shall be in accordance with the AASHTO LRFD Bridge Design Specifications.406.03 493Mechanical butt splicing will be permitted at locations shown on the plans. The mechanical connection shall develop in tension or compression, as required, 125 percent of the specified yield strength of the bar. The total slip of the bar within the splice sleeve of the connector after loading in tension to 30.0 ksi and relaxing to 3.0 ksi shall not exceed the following measured displacements between the gage points clear of the splice sleeve: For bar sizes up to No. 14: 0.01 inch For No. 18 bars: 0.03 inch For corrosion resistant reinforcing bars, mechanical butt splicers shall be of the same material as the bars being spliced. Reinforcing steel shall be welded only if specified on the plans. Welding shall be in accordance with Section 407.04(a). Reinforcing steel conforming to ASTM A615, Grade 60 shall not be welded. Corrosion resistant reinforcing steels shall not be welded. Lap lengths for welded wire fabric or bar mat reinforcement shall be in accordance with the current AASHTO LRFD Bridge Design Specifications.
406.04 Measurement and Payment
Reinforcing steel will be measured in pounds of steel placed in the structure as shown on the plans. The weight of welded wire fabric will be computed from the theoretical weight per square yard placed, including allowance for laps not to exceed 8 percent of the net area. Reinforcing steel or welded wire fabric will be paid for at the contract unit price per pound. These prices shall include furnishing, fabri - cating, and placing reinforcement in the structure. In structures of reinforced concrete where there are no structural steel contract items, expansion joints, plates, rockers, bolts, and similar minor metal parts will be paid for at the contract unit price for reinforcement. Corrosion resistant reinforcing steel, when a pay item, will be measured in pounds and will be paid for at the contract unit price per pound of the designated class of steel indicated and placed in the structure in the location(s) shown on the plans. This price shall include fabricating, shipping, furnishing and placement. No payment will be made for fastening or support devices that may be used by the Contractor for keeping reinforcing bars in their correct position. When the substitution of larger bars than those specified is allowed, payment will be made for only the amount of metal that would have been required if the specified size of bar had been used. When full-length bars are shown on the plans and the Contractor obtains approval to use short bars for his convenience, the weight paid will be based on the full-length dimensions with no allowance made for splices. Payment will be made under: —————————————— ————————————— Pay Item Pay Unit——————————————————————————— Reinforcing steel Pound Welded wire fabric Pound Corrosion resistant reinforcing steel, (Class) Pound———————————————————————————406.04 494SECTION 407—STEEL AND OTHER METAL STRUCTURES
407.01 Description
This work shall consist of furnishing, fabricating, and erecting steel or other metal materials in accordance with these specifications and in conformity with the lines, grades, and dimensions shown on the plans or as established by the Engineer.
407.02 Materials
Steel shall conform to Section 226. Other metals shall conform to their respective sections of the Specifications.
407.03 Working Drawings
The Contractor shall submit to the Engineer working drawings of all structural steel, bearing assemblies, and anchorage devices to be used in the work on the contract for the Engineer’ s review and acceptance. Details shown on the working drawings shall conform to these specifications and the Structural Steel Design Section of the current AASHTO LRFD Bridge Design Specifications. In addition, primary stress units shall be detailed and identified by an individual piece mark. The Engineer’ s review of working drawings shall not relieve the Contractor of responsibility for errors on the drawings or deviations from the plans made by the Contractor unless such changes are preapproved in writing by the Engineer. Shop work shall not be performed until after the working drawings have been reviewed and accepted. The Contractor may, in writing, authorize the fabricator to act for the Contractor in matters relating to the working drawings in accordance with Section 105.10. If authority is granted by the Contractor to the fabricator, a copy of such authorization shall be provided to the Engineer. Working drawings shall specifically identify the composition and grade of metal or alloy of each piece other than steel conforming to ASTM A709, Grade 36. Pieces fabricated of different grades of steel shall not be given the same piece mark, even if they have identical dimensions and details.
407.04 Fabrication Procedures
Workmanship, finish, and fabrication tolerances shall conform to AISC standards and AWS welding codes except where the standards are in conflict with these specifications. Where AISC standards and AWS welding codes allow alternate methods of fabrication, the method used by the fabricator shall be that which produces the higher quality of workmanship and finish. Structural steel shall be fabricated in a shop certified by AISC under the Certification Program for Structural Steel Fabricators. Fabricators producing fracture-critical members, intermediate bridges, or advanced bridges shall be required to meet the supplemental requirements as appropriate. All structural steel fabrication not specifically covered under the Certification Program for Structural Steel Fabricators shall be fabricated in a shop certified by AISC under the Certification Program— Standard for Bridge and Highway Metal Component Manufacturers. All complex coating systems, defined as coatings which require special care in surface preparation, coating, component preparation, application control, curing, and in-process inspection, applied to 407.01
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 517–521 of 1,065.