514Reinforcing Steel

Reinforcing Steel

514.1DESCRIPTION

1 This section describes the requirements for furnishing and placing reinforcing steel.

514.2MATERIALS

514.2.1 Reinforcing Steel

1 Provide materials in accordance with the following:

Material Subsection Reinforcing Steel 811.1

514.2.2 Reinforcing Steel Supports and Ties

1 When using metal supports, provide with legs curved to form a hook, with the ends at least ⅛ in [3 mm] above the form work. Protect metal supports for uncoated reinforcing steel that are in contact with the exterior surface of the concrete by galvanizing or coating with plastic or epoxy. Ensure that coatings do not chip, crack, deform, or peel. Extend protection at least ½ in [12 mm] above the form work. Apply plastic protection by dipping; ensure a minimum thickness of 1/16 in [2 mm] at points of contact with form work.

2 Coat metal supports for epoxy-coated reinforcing steel completely with epoxy or plastic. Use galvanized metal supports for galvanized reinforcing steel. For coated bars, provide support legs in accordance with the dimensional and coating requirements for uncoated bars.

3 Use plastic- or epoxy-coated tie wires for epoxy-coated reinforcing steel, galvanized tie wires for galvanized reinforced steel, and stainless-steel tie wires for use with mechanical tying equipment.

514.2.3 Mechanical Reinforcing Steel Splices

1 Provide mechanical reinforcing steel splices consisting of a lap or butt splice system capable of developing at least 125 percent of the specified yield strength for the reinforcing steel. When epoxy coating is specified, shop- or field-coat the mechanical splice and adjacent material as necessary with epoxy in accordance with Subsection 811.1, Reinforcing Steel, or seal the splice with an approved heat-shrink plastic sleeve in accordance with the sleeve manufacturer’s recommendations.

Reinforcing Steel SECTION 514

514.3EQUIPMENT

1 Automated equipment for tying reinforcing steel may be used provided it produces ties as strong and tight as those tied by hand and does not damage coatings.

514.4CONSTRUCTION

514.4.1 General

1 The engineer will test reinforcing steel before use. Provide two test samples 4.5 ft [1.5 m] long for each manufacturer, heat number, and size of reinforcing bar and spiral wire delivered; include a certification indicating the heat number and sizes of material.

2 The engineer may also require two flame- or saw-cut samples 4.5 ft [1.5 m] long of any grade 60 [400] bar delivered. Replace samples with splice bars from the same heat number and long enough to lap the bar from which the sample was cut, in accordance with Table 514.4.5-1, Minimum Lap Lengths for Reinforcing Steel Splices.

514.4.1.1 Coated Reinforcing Steel

1 For coated reinforcing steel, use green epoxy-coated or galvanized reinforcing steel. Use only one type of coating on a project.

2 Handle, ship, store, and place coated reinforcing steel without damage to the coating. Use handling and bundling systems that are padded. To prevent bar-to- bar abrasion, use a strongback, multiple supports, or platform bridge to minimize sagging. Do not drop or drag bars or bundles. Store bars above the ground surface on wooden or padded supports.

3 Ensure that epoxy coatings damaged during fabrication are repaired before shipping. Before installation, regardless of source or cause, clean and repair damaged epoxy coatings with patching material in accordance with Subsection 811.1, Reinforcing Steel Repair galvanized surfaces in accordance with Subsection 501.4.2.9, Repair of Galvanizing.

4 Replace the bar if more than 2 percent of its surface area is damaged.

514.4.2 Reinforcing Steel Order Lists

1 Unless the contract includes a bar list with bending diagrams, submit (on 8½ in × 11 in [210 mm × 297 mm] paper) order lists for reinforcing steel. Include all data necessary for complete fabrication and supply. For each structural unit, abutment, bent, or slab, detail the reinforcing steel, and include a complete list of bars. Do not combine lists. Indicate the name of the structure, route, station, project number , and drawing number , when applicable.

Reinforcing Steel SECTION 514

2 Before fabricating, ensure that the supplier submits two sets of complete advance order lists for each structure to the State Bridge Engineer for approval and notifies the engineer of this submittal. The State Bridge Engineer will return one set to the supplier with necessary corrections noted. Ensure that the supplier furnishes seven corrected sets of the order lists to the State Bridge Engineer, each marked “Final.” If these sets are correct, one set will be returned to the supplier to begin fabrication. Do not fabricate before obtaining the State Bridge Engineer’s approval.

3 On the final order lists and in the transmittal letter, clearly identify changes made between the advance and the final lists, other than those requested by the engineer. Do not then change size, dimensions, or material from those shown on the final order lists without the engineer’s written approval.

4 The department’s approval of an order list is an acceptance of the character and sufficiency of the list and does not relieve the contractor of responsibility for errors or omissions. Make changes to comply with the contract at no additional cost to the department.

514.4.3 Protection of Materials

1 Protect reinforcing steel from damage; ensure steel is free from dirt, detrimental scale, paint, oil or other foreign substances. Tight surface rust may remain; however, remove loose rust scale. Replace reinforcing steel that has excessive rust and can impair bonding. Remove cement mortar adhering to exposed reinforcing steel due to previous placement.

514.4.4 Bending

1 Cold bend reinforcing bars. Do not field-bend reinforcing steel partially embedded in concrete. Cut and bend reinforcing steel in accordance with the ACI Manual of Practice for Detailing Reinforced Concrete Structures. Do not use methods producing kinks or improper bends.

2 Fabricate reinforcing steel bends and hooks in accordance with the ACI Manual of Practice for Detailing Reinforced Concrete Structures. Except for 135-degree and 180- degree hooks, the department specifies dimensions in bending diagrams measured out-to- out.

3 Provide and use spirals with 1½ extra turns at each end for anchorage. Provide channel spacers with each spiral to hold the spiral bar firmly in place while placing concrete. Use in accordance with Table 514.4.4-1, Channel Spacer Requirements for Spiral Reinforcing Steel.

Reinforcing Steel SECTION 514

Table 514.4.4-1 Channel Spacer Requirements for Spiral Reinforcing Steel Core Diameter No. of Spacers ≤ 20 in [510 mm] 2 21 in [530 mm] to 30 in [760 mm] 3 ≥ 30 in [760 mm] 4 No 5 [16 mm] spiral bars 4

514.4.5 Placing and Fastening

514.4.5.1 General

1 Place reinforcing steel accurately; hold firmly with supports in the position specified. Tie reinforcing bars securely at all intersections using No. 16 gage [1.5 mm] or heavier wire. Where bars are spaced closer than 12 in [300 mm] in each direction, tie alternate intersections. Multiple wires with combined cross- sectional areas equal to or greater than that of a No. 16 gage [1.5 mm] may also be used. Do not fasten reinforcing steel by tack welding.

2 The department specifies spacing dimensions for reinforcing steel by referring to the centers of bars.

3 When not specified, ensure a concrete cover of 2 in [50 mm] to the face of reinforcing steel.

4 Provide reinforcing bars in the full lengths specified; do not splice except to replace test samples.

5 Overlap welded wire fabric ends and sides at least one mesh opening and fasten with wire or other approved fasteners at intervals of 12 in [300 mm].

6 Tie bundled reinforcing bars together at a maximum of 6 ft [1.8 m] centers.

7 Hold reinforcing bars in position with precast mortar blocks, ferrous metal chairs, spacers, metal hangers, plastic supports, or supporting wires capable of supporting applied loads. Do not use wooden or aluminum supports. Do not place bars on fresh concrete, adjust bars during concrete placement, or insert bars after placing concrete.

514.4.5.2 Reinforcing Steel Splices

514.4.5.2.1 Lap Splices

1 Overlap bars in accordance with Table 514.4.5-1, Minimum Lap Lengths for Reinforcing Steel Splices.

Reinforcing Steel SECTION 514

Table 514.4.5-1 Minimum Lap Lengths for Reinforcing Steel Splices Bar Size (No.) Lap Length Uncoated Bars Coated Bars 4 [13] 2 ft 5 in [710 mm] 2 ft 11 in [860 mm] 5 [16] 3 ft 0 in [880 mm] 3 ft 8 in [1070 mm] 6 [19] 3 ft 9 in [1070 mm] 4 ft 6 in [1300 mm] 7 [22] 5 ft 1 in [1460 mm] 6 ft 1 in [1770 mm] 8 [25] 6 ft 8 in [1930 mm] 8 ft 1 in [2340 mm] 9 [29] 8 ft 5 in [2430 mm] 10 ft 2 in [2950 mm] 10 [32] 10 ft 8 in [3090 mm] 12 ft 11 in [3750 mm] 11 [36] 13 ft 1 in [3790 mm] 15 ft 10 in [4610 mm]

2 Distribute splices well or locate at points of minimum tensile stress. Wire splice bars together rigidly. Where bars are offset from each other, wiring may be omitted if the bar ends are held in proper position, as specified. When approved by the engineer , make splices in spiral reinforcement with an overlap of 1½ turns. Do not use overlap splices on bars larger than No. 11 [36].

514.4.5.2.2 Welded Splices

1 When specified or approved by the engineer, splice reinforcing bars by welding in accordance with AASHTO/AWS D1.4, Structural Welding Code - Reinforcing, and using AASHTO/AWS E 7018 welding electrodes. Use electrodes from hermetically sealed containers within four hours of opening the container, unless stored in ovens at a temperature of at least 250 °F [120 °C]. Before welding, obtain department approval of the proposed procedure and welder qualifications.

Splice Welds

Reinforcing Steel SECTION 514

Reinforcing Steel SECTION 514

2.1Do not weld when air temperature is below 0 °F [-18 °C].

2.2Free surfaces to be welded and those adjacent from loose or thick scale,

slag, rust, grease, or other foreign material that would prevent proper welding. Mill scale that withstands vigorous wire- brushing may remain. Remove epoxy coating from surfaces to be welded and those adjacent for at least 3 in [75 mm].

2.3Do not allow gaps greater than ⅛ in [3 mm] between the bar being spliced

and the lap bar. If necessary, grind deformations to achieve this gap.

2.4Do not undercut deeper than 1/16 in [2 mm] where welds intersect the raised

pattern of deformations; elsewhere, undercut no deeper than 1/32 in [1 mm].

2.5Preheat bars to be welded to at least 500 °F [260 °C] at the cross-section

of the weld area and 6 in [150 mm] on each side, as indicated by temperature-indicating crayons provided at no additional cost to the department. Cool bars naturally to air temperature after welding.

2.6Make tack welds at least 2 in [50 mm] long, using preheat and quality

requirements applicable to permanent welds. Do not make tack welds that will not become part of the permanent weld.

2.7When welding in the vertical position, make passes upward.

2.8Avoid arc strikes outside permanent weld areas. If they occur, grind them

smooth.

2.9Fill the cross-section of flare, V-groove welds at least flush with the bar

surface.

2. 10 Use welders that have been qualified beforehand in accordance with the department’s welder qualification process for each position in which welds will be made.

2.11After welding epoxy-coated bars, clean welds and adjacent uncoated areas

of slag and other foreign material that would interfere with adhesion of epoxy coating, and recoat with material in accordance with Subsection 811..1, Reinforcing Steel.

Reinforcing Steel SECTION 514

514.4.5.2.3 Mechanical Splices

1 When specified or approved by the engineer, install mechanical reinforcing steel splices in accordance with manufacturer’s recommendations. Expose a sufficient length of reinforcing steel to allow mechanical splicing, clean and straighten as required. Remove and replace improper splices at no additional cost to the department.

514.4.6 Deck Slab Reinforcing Steel System

1 Construct a support system to stabilize the bridge deck slab reinforcing steel mats in all directions, to prevent movement by workers placing concrete, and to support the weight [mass] of the concrete. Do not use mortar blocks, bricks, wood, or aluminum supports. At the least, support the top and bottom layers of steel in the different types of reinforcing systems as follows:

“crank” reinforcing bar in the deck slab reinforcement. Support the bottom layer of reinforcing steel with continuous, longitudinal, slab- bolster supports spaced transversely between girders. Place the first supports no more than 24 in [600 mm] from the centerline of a girder. Place one support at each bend of the crank bar. Do not place transverse supports farther than 4 ft [1.2 m] apart. Use additional supports if the distance between bends, or to a bend from the first support location of the crank bar exceeds 4 ft [1.2 m]. Support the top layer of reinforcing steel with either continuous, longitudinal, high-slab bolsters or individual high supports. Place the first supports no more than 24 in [600 mm] from the centerline of girders, with other supports placed at bends with the same limits, not exceeding 4 ft [1.2 m], as described for the bottom layer. When using individual high supports, place under a longitudinal deck reinforcing bar in a continuous row , spaced no more than 4 ft [1.2 m] apart longitudinally.

I f crank bar placement leaves the top mat of reinforcing too high to provide the specified clearance, lay it over slightly.

bottom layer of reinforcing steel for the deck cantilever with continuous, longitudinal, slab-bolster type supports. If the cantilever exceeds 24 in [600 mm] from the centerline of the exterior girder, place one support near the end of the cantilever and one midway between the centerline of the exterior girder and the cantilever deck end.

Support the top layer of reinforcing steel with continuous, longitudinal, high -slab bolsters or individual high supports. Place the supports in the same manner as, and within the limits imposed for, the bottom layer of the cantilever. When using individual high supports, place under a longitudinal deck reinforcing bar in a continuous row, spaced no more than 4 ft [1.2 m] apart longitudinally.

Reinforcing Steel SECTION 514

reinforcing steel with continuous, longitudinal, slab- bolster type supports, spaced transversely between girders. Place the first supports no more than 24 in [600 mm] from the centerline of a girder and additional supports between the first supports, spaced no more than 4 ft [1.2 m] apart. Support the top layer of reinforcing steel of separate mats with continuous, longitudinal, high-slab bolsters; individual high supports; or continuous, transverse slab supports spaced longitudinally. Place the first supports no more than 24 in [600 mm] from the centerline of girders and other supports with the same limits, no more than 4 ft [1.2 m] apart, described for the bottom layer. When using individual high supports, place under a longitudinal deck reinforcing bar in a continuous row, spaced no more than 4 ft [1.2 m] apart longitudinally.

When using continuous transverse slab bolsters with runners, place the bolsters between the bottom and top layers of reinforcing steel, spaced no more than 4 ft [1.2 m] apart longitudinally. Secure the top and bottom layers of reinforcement together with No. 16 gage [ 1.5 mm] or heaver tie wire, or with multiple ties of equivalent cross-sectional area, at intervals of 4 ft [1.2 m] in each direction.

bottom layer of reinforcing steel for this system in the same manner and with the same limits used for the truss-bar type. Support the top layer in the same manner and with the same limits used for the truss -bar type or by using transverse slab bolsters with runners. Extend the bolsters and runners to the end of the cantilever.

2 These slab reinforcement methods are minimum requirements. Do not use them to support concrete buggies, material carts, or other equipment. If additional equipment is anticipated or used, increase the number of supports as necessary to provide the needed support.

3 Secure the entire network of reinforcing steel by fastening to each girder line. Tie the top layers of reinforcing bars down to deck form-hangers, shear connectors, or exposed stirrup tops with No. 16 gage [1.5 mm] or heavier wire, or multiple ties of equivalent cross- sectional area. Space the ties at intervals no farther apart than 4 ft [1.2 m] on- center longitudinally for the length of girder.

4 After placing and adjusting screed supports and rails, make a “dry run” with the screed machine along the deck to ensure the specified top clearance to the reinforcing steel. Ensure that the top and bottom clearance is not more than ¼ in [6 mm] less than the clearance specified. Ensure that the spacing between the top and bottom layers of reinforcing steel is within ¼ in [6 mm] of that specified. If these tolerances are not met, adjust screed line elevations or reset the top reinforcing steel at no additional cost to the department.

Reinforcing Steel SECTION 514

514.5MEASUREMENT and PAYMENT

1 The engineer will measure:

required for the placement of the selected mechanical splices will not be measured for additional payment.

pound [kilogram] for the quantity specified.

2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest Mechanical Splices LS, EA [Ea] LS, EA [Ea] LS, EA [Ea] Reinforcing Steel LS, LB [LS, kg] LS, lb [LS, kg] LS, 10 LB [LS, 5 kg] Reinforcing Steel (Coated) LS, LB [LS, kg] LS, lb [LS, kg] LS, 10 LB [LS, 5 kg]