502.03 Construction Requirements.
STEEL REINFORCEMENT
502.01 Description.
This Section shall cover the work of furnishing and installing reinforcement steel for concrete structures in accordance with detailed plans and these Specifications.
502.02 Materials.
a.General Requirements . All materials shall conform to applicable portions of Division 800, Materials. Specific reference is made to Section 835, Steel Reinforcement. Steel mesh shall be use d only when and as shown on the plans. Special attention is directed to Article 835.01 for the use of rail steel reinforcing bars in structures. All reinforcing bars when shipped from the fabricator or supplier to the project site shall conform to the foll owing bundling and tagging practice:
1.Bundling: All bundles shall consist of the same size bars and the same heat number.
2.Tags: Tags shall be made of durable material and marked in a legible manner with waterproof markings, not less than one tag per bundle. The tags shall show the grade, number of pieces, size, marks or length of bar, and heat number of steel. The supplier of the reinforcing steel shall furnish to the Engineer three copies of an itemized list of all steel included in each shipment. S uch list shall show the mark of the bar, bar number, heat number, grade, length, and weight {mass} of all steel for each structure requiring reinforcing steel.
b.Bar Bending Diagrams . When bar lists and bending diagrams are shown on the plans, the Contra ctor shall verify their accuracy from the drawings. Errors in the bar bending schedules and bar list shall not be cause for adjustment of contract unit prices.
502.03 Construction Requirements.
a.General . All reinforcement received on the project shall be placed in approved storage and shall be maintained clean, intact, and free from distortion. Reinforcement shall be free from loose or thick rust which would impair bond of the steel with the concre te. Rust that produces only discoloration without reducing the cross section of the steel will not be considered objectionable. Only such reinforcement shall be distributed along the construction as is needed for immediate use.
b.Equipment . All equipment necessary for the proper fabrication, bending, handling, and installation of reinforcement must be available when required, in first class working condition, and shall be approved before fabrication and construction will be permitted to begin.
c.Handlin g and placing Reinforcement .
1.Bending . Reinforcement shall be bent in accordance with CRSI Manual of Standard Practice MSP -1-97, accurately to the form and dimensions shown on the plans without heating. In bending, care shall be taken not to injure the steel and only proper appliances and competent workmen shall be employed on the work. The radius of bends shall be three or more times the diameter of the bar unless shown otherwise on the plans. Abrupt bends shall be avoided. Any reinforcement bent du ring shipment or handling shall be properly reshaped, without heating to a higher temperature than that producing a dark cherry -red color, before being placed in the work. Bars with kinks or bends and bars appreciably reduced in cross sectional areas shall be rejected.
2.Cleaning . Metal reinforcement before being placed shall be cleaned of loose mill scale and of coatings of dirt, paint, oil, grease, or any other foreign substance.
3.Placing . All reinforcing steel shall be accurately placed and firmly held in the position shown on the plans during the placing and hardening of the concrete.
502.03 Construction Requirements.
A + 1/4 inch { + 6 mm} vertical placement tolerance will be allowed on the top mat of reinforcing steel in the bridge decks.
4.Wiring and Supporting .
a.All reinforcement shall, as elected by the Contractor, be (1) rigidly wired, or (2) if approved by the Engineer, spot welded. Suitable provision shall be made for supporting reinforcement in position during the placing of concrete. No construction operation sha ll be permitted which tends to bend or displace the reinforcement from its correct position. All reinforcement shall be placed and securely wired, spaced, and blocked before placing concrete in any section. Railing post reinforcement shall be installed bef ore placing the curb concrete. In no case shall reinforcing steel be driven or forced into concrete after it has set.
b.All reinforcing metal shall be maintained at the proper distance from the forms or in the case of layers, from each layer by means of a pproved stays, mortar blocks, metal chairs, ties, hangers, or other approved supports.
c.Mortar blocks shall be precast from a mortar mix composed of one part Portland cement and two parts concrete sand with wires cast into them for fastening to the steel. Blocks shall be moist- cured (other curing methods may be accepted) for at least three days before use. Block basic shape shall be a square (2 inch {50 mm} x 2 inch {50 mm} Min.) with appropriate height as required to hold the steel in its designated pos ition (+ 1/8 inch , - 0 inch {+ 3 mm, - 0 mm}). The size and shape shall be approved before use. Tie wires shall be 0.064 inch {1.6 mm} minimum diameter.
d.Metal supports shall be in accordance with CRSI Manual of Standard practice MSP -1-97 for Class 3 bar supports except that supports which are to be in direct contact with removable forms shall be Class 1 supports. Any premolded Class 1 support tips that do not provide a tight snug fit shall be rejected and removed from the work.
e.The use of pebbles, pi eces of broken concrete, stone or brick, metal pipe, and wooden blocks will not be permitted.
5.Inspection .
a.Reinforcement in any member shall be placed, and then inspected and approved before the placing of concrete begins. Concrete placed in violation of this provision shall be rejected and removed at no additional cost to the State.
b.Extreme care shall be taken to insure that the final location of bars in the top of floor slabs, sidewalks, curbs, and beams are not lower than the clear distance from the top of the finished slab as shown on the plans.
d.Splicing and Lapping Steel Reinforcement .
1.Splicing. Whenever it is necessary to splice reinforcement at points other than those shown on the plans, drawings showing the locations and details of eac h splice shall be submitted by the Contractor and approved before the reinforcing steel is ordered by the Contractor. Splices shall be avoided at points of maximum stress; they shall, where possible, be staggered, and shall be designed to develop the stren gth of the steel without exceeding the allowable unit bond stress. Unless otherwise shown on the plans, bars shall be lapped 24 diameters to make the splice in the slab and in the bottom of beams and girders, and not less than 35 diameters in walls, column s, haunches, and near the tops of beams and girders having more than 12 inches {300 mm} of fluid concrete under the bars. In lapped splices, the bars shall be placed in contact and wired together in such a manner as to maintain a clearance of not less than the minimum clearance distance to the surface of the concrete. Welding of reinforcing steel shall be done only if detailed on the plans or if authorized in writing. Welding shall conform to the current specifications for welded highway and railway bridges of the American Welding Society.
2.Lapping . Sheets of mesh or bar mat reinforcement shall overlap each other sufficiently to maintain a uniform strength and shall be securely fastened at the ends and edges. The edge lap shall not be less than one mesh in width.
3.Restrictive Conditions for the Welding of Reinforcing Bars . Reinforcing bars shall not be welded unless shown otherwise on the plans or approved by the Bridge Engineer.
502.04 Method of Measurement.
4.Butt Splicing . Reinforcing bars shall be butt spliced only when shown on the plans. The butt splice shall be a mechanical coupling splice. The mechanical coupling shall be made with a coupler that can develop, in tension, at least 125 percent of the specified yield strength (fy) of the bar. The Contractor shall prepare three test splices using the proposed method of splicing and reinforcing bars obtained from the supplier of the reinforcing steel. These test splices and two unspliced bars will be tested by the Alabama Department of Transportation's Bureau of Materials and Te sts. The tension tests will be performed on full cross section specimens in accordance with ASTM E 8 {E 8M}, using a gage length that spans the extremities of the connector. Complete details of the mechanical splice and the methods and equipment proposed for use in making the splice shall be submitted to the Department for approval.
502.04 Method of Measurement.
a.Lump Sum Unit Measurement . The steel reinforcement required for a bridge superstructure will be measured for payment as a lump sum unit.
b.Theoretical Unit Weight {Mass} Measurement. The theoretical unit weight {mass} in pounds {kilograms} shall be used as the method of measureme nt for steel reinforcement where no other method of measurement is given for payment purposes. The weight {mass} of steel paid for shall be the number of pounds {kilograms} of steel, acceptably placed as shown to be required on the plans or as directed by the Engineer. The unit weight {mass} used for deformed bars shall be the weight {mass} of plain, square, or round bars, as the case may be, of equal nominal size. If steel mesh or expanded metal is required, the weight per square foot {mass per square meter} will be shown on the plans. The actual quantity measured for payment will be that shown on the itemized list specified in Subarticle 502.02(a) with deductions made for: • errors in number, size, or length of bars shipped; • steel reinforcement used in a str ucture where the cost of the steel is included in the cost of the structure; • steel reinforcement in bridge concrete superstructure units; • discrepancies or errors in the list itself.
c.Areas, Dimensions, and Weights {Masses }. Area dimensions and weights { masses} to be used in calculations for the various size bars shall be as follows: Bar Designation Number Weight {Mass} Pounds per foot {kg / m} Diameter inches {mm} Cross -Sectional Area square inches {mm 2} 2 0.167 0.250 0.05 3 {10} 0.376 {0.560} 0.375 {9.5} 0.11 {71} 4 {13} 0.668 {0.994} 0.500 {12.7} 0.20 {129} 5 {16} 1.043 {1.552} 0.625 {15.9} 0.31 {199} 6 {19} 1.502 {2.235} 0.750 {19.1} 0.44 {284} 7 {22} 2.044 {3.042} 0.875 {22.2} 0.60 {387} 8 {25} 2.670 {3.973} 1.000 {25.4} 0.79 {510} 9 {29} 3.400 {5.060} 1.128 {28.7} 1.00 {645} 10 {32} 4.303 {6.404} 1.270 {32.3} 1.27 {819} 11 {36} 5.313 {7.907} 1.410 {35.8} 1.56 {1006}
d.Splicing . Weight {mass} allowance will be made for only those splices shown on the plans. No weight {mass} allowance will be made for splices for the Contractor's convenience.
e.Miscellaneous Metal Parts .
1.No allowance will be made for any device, material, or method which may be used for splicing, clamping, tying, butt welding, and keeping reinforcement in proper position.
2.When the proposal form omits pay items for other metal parts indicated and required in connection with the construction of concrete structures, and compensation for such parts is not
502.05 Basis of Payment.
elsewhere provided in these specificat ions or on the plans, the weight {mass} of such other metal parts will be included in the weight {mass} computed for steel reinforcement.
502.05 Basis of Payment.
a.Unit Price Coverage . Where the unit of measurement for steel reinforcement is pounds {kil ograms}, the weight {mass} of steel reinforcement determined as provided above shall be paid for at the contract unit price per pound {kilogram}, which price and payment shall be full compensation for fabricating, furnishing, placing, and butt welding all materials, and for all labor, equipment, tools, and incidentals necessary to complete the Item in accordance with plan details. The reinforcement required for a bridge superstructure shall be paid for at the contract unit price bid per lump sum for steel r einforcement for bridge superstructure which shall be full compensation for fabricating, furnishing, and placing all materials in accordance with plan details. The contract unit bid price shall also be full compensation for all labor, equipment, tools, and incidentals necessary to complete this item of work. An increase, or decrease, in the quantity of steel reinforcement for a bridge superstructure from that shown on the plans, which is caused by a change in the plans after the contract has been let, will result in an increase, or decrease, in the compensation due the Contractor. Changes to the compensation for the superstructure reinforcing steel will be made by applying the percentage of the increase or decrease to the contract lump sum price for Pay Item 502-B, Steel Reinforcement For Bridge Superstructure.
b.Payment will be made under Item No .: 502-A Steel Reinforcement - per pound {kilogram} 502-B Steel Reinforcement For Bridge Superstructure, *, **, *** - per lump sum * Station Number, Bridg e Number, Ramp Number, etc. ** Lane, if applicable *** Approximate quantity of reinforcing steel in pounds {kilograms} SECTION 503 STRUCTURE FOUNDATIONS
503.01 Description.
The work under this Section shall cover preparing foundations for bridges, box culverts and other miscellaneous structures. These foundations shall be built in accordance with the details shown on the plans and the provisions provided in this Section.
503.02 Materials.
Materials used in the work required under this Section shall conform to the applicable requirements provided elsewhere in these Specifications. Members designated as mass concrete shall meet the applicable requirements found in Section 510.
503.03 Construction Requirements.
a.General . In the construction of found ations, it is the intent that the foundations be constructed in the dry insofar as practical. Excavation shall be in accordance with Section 214 or 215, whichever is applicable. Where excavation is near a railroad track, the Contractor shall install such shoring and sheeting as deemed necessary by the Engineer and the Chief Engineer of the railroad company involved. Provisions of Article 107.08 shall govern. Where the excavation is near a building, utility or other property, the Contractor shall install shoring and sheeting and perform such other work as shown on the plans for proper protection of the property, and, in addition, shall comply fully with the requirements of Article 107.12 regarding protection of property.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 308–310 of 934.