502STEEL REINFORCEMENT

308

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 Tests. 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.

502.04Method of Measurement

The steel reinforcement required for a bridge superstructure will be measured for payment as a lump sum unit.

The theoretical unit weight {mass} in pounds {kilograms} shall be used as the method of measurement 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 structure 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.

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 {mm2} 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}

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.

clamping, tying, butt welding, and keeping reinforcement in proper position.

connection with the construction of concrete structures, and compensation for such parts is STRUCTURE FOUNDATIONS 309

not elsewhere provided in these specifications or on the plans, the weight {mass} of such other metal parts will be included in the weight {mass} computed for steel reinforcement.

502.05Basis of Payment

Where the unit of measurement for steel reinforcement is pounds {kilograms}, 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 reinforcement 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.

502-A Steel Reinforcement - per pound {kilogram} 502-B Steel Reinforcement For Bridge Superstructure, *, **, *** - per lump sum * Station Number, Bridge Number, Ramp Number, etc. ** Lane, if applicable *** Approximate quantity of reinforcing steel in pounds {kilograms} STRUCTURE FOUNDATIONS

503.01Description

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.

503.02Materials

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.

503.03Construction Requirements

In the construction of foundations, 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.

The elevation of the bottoms of footings, as shown on the plans, shall be considered as approximate only and the Engineer may order, in writing, such changes in dimensions or elevations of footings as may be necessary to secure a satisfactory foundation. STRUCTURE FOUNDATIONS 310

All rock or other hard foundation material shall be freed from all loose material, cleaned and cut to a firm surface, either level, stepped, or roughened, as may be directed by the Engineer. Where seams, voids, cracks, or crevices exist, they shall be cleaned out and filled as directed by the Engineer. In rock, the openings shall be filled with sub footing concrete (Class A concrete) if the concrete can be placed in the dry. (Refer to Articles 503.04 and 503.05 concerning measurement and payment.) If the concrete cannot be placed in the dry, the Contractor shall propose a method for filling the openings for review and approval by the Engineer. In hard, dry material other than rock, the Engineer may allow the use of Item 214-B, Foundation Backfill, or direct the use of sub footing concrete. When the footing is to rest on an excavated surface other than rock, special care shall be taken not to disturb the bottom of the excavation and the final removal of the foundation material to grade shall not be made until just before the footing is to be placed.

Where rock or hard foundation material is available, excavation for the footing shall be to neat lines and the concrete poured against the excavated walls without forms, unless otherwise approved by the Engineer. Concrete used to replace rock or hard foundation material excavated outside of the neat lines will not be measured for payment.

If the material encountered at the elevation shown on the plans for the bottom of footing is of a soft and unstable nature lacking in the required bearing value, and tests show the existence of satisfactory material of sufficient thickness and bearing value at a depth of less than 10 feet {3 m} below the elevation shown on the plans for such footing, the Engineer may order that the footing be lowered into the satisfactory material and/or that the dimensions of the footing be increased.

The excavation of each pit shall be completed before the piles are driven. After driving is completed, all loose and displaced material shall be so removed as to leave a smooth solid bed to receive the footing.

Foundation backfill shall be used as directed by the Engineer. Attention is directed to Section 214 or 215, whichever is applicable.

The construction adjustments permitted above shall not be considered as materially altering the original plans and shall not be a waiver of any condition of the contract nor invalidate any of the provisions thereof.

In the construction of footings and substructures, the item of Cofferdam and Pumping shall be used on all piers or bents where so designated on the plans. Working drawings and computations shall be submitted in accordance with Article 105.02. Attention is directed to Section 215 for piers and bents not designated to receive the item of Cofferdam and Pumping.

Interlocking, steel sheet piling of 3/8 inch {9.5 mm} minimum web thickness shall be used in all cofferdam work. The tops of the cofferdams shall be well above the normal water stages and their bottoms shall be carried to a depth that will prevent flow of materials into the excavation. They shall be constructed in a substantial manner, capable of resisting earth, water or concrete without appreciable displacement, distortion or leakage. Interior clear dimensions of cofferdams shall be such as will provide sufficient clearance for construction and removal of forms and for a sump outside the footing where footings are to be poured in the dry. No excess excavation and seal concrete will be paid for where the Contractor elects to use an oversized cofferdam for his convenience.

Cofferdams shall not be removed until after the substructure has been constructed above normal water elevation or above the ground lines, whichever is applicable, and after the Engineer has inspected STRUCTURE FOUNDATIONS 311

the work. Care shall be taken in removing the temporary construction so as not to damage the footings and columns. Any damage as a result of the cofferdam removal shall be replaced or repaired without additional compensation from the Department. Cofferdam sheet piling shall remain permanently in- place and undisturbed if this is shown to be required on the plans.

All substructure concrete shall be placed in the dry unless otherwise provided on the plans. Pumping during the placing of foundation concrete shall be done from a suitable sump separated from the concrete work and shall be so conducted that there will be no water currents inside the forms or inside the excavation if no forms are required. Pumping equipment shall in all cases be of ample capacity to keep the excavation practically free of water until all the concrete is in place. Water that originates in the footing area or that is necessary to come through or across the footing area shall be handled in approved pipes or conduits to the pump sump. Cofferdams shall be dewatered for inspection purposes without additional compensation when requested.

Seal concrete shall be used by the Contractor only when required by plan details as a structural footing or when directed by the Engineer in accordance with the following conditions. If the material encountered at the designed elevation of the bottom of the footing is so porous that water enters at such a rate that it is impractical to lower water level to this elevation by pumping, or if the material is so plastic that it cannot be prevented from flowing into the excavation by driving sheeting to reasonable depths, the Engineer may require the Contractor to seal the cofferdam with concrete. The seal concrete shall be placed in the manner prescribed in Section 501. After placement of seal concrete, the cofferdam shall not be dewatered for seven days or until concrete has, by test, indicated a compression strength of 2000 psi {14 MPa}. Immediately prior to placing seal concrete on a rock surface, the footing floor shall be cleaned by airlift or other acceptable methods. After cleaning, any mud, silt, etc., which is impossible to remove shall be agitated by means of compressed air jet so that this material will be suspended in the water during the placing of seal concrete. All footings which are to receive seal concrete, except pile footings, will require an underwater inspection by the Department prior to placing the seal unless approved otherwise by the Engineer. The Contractor shall give at least a 48 hour notice prior to the need for an underwater inspection. The Contractor shall provide transportation to the cofferdam cell and a work station for the diver and his equipment. If the footing floor is found to be unacceptable another underwater inspection will be required after corrections are made.

Pile footings will not be required to be cored unless noted otherwise on the plans or ordered by the Engineer. All other seal concrete footings shall be cored in accordance with the following procedure. Cores shall be taken by the Contractor for use by the Engineer in determining the quality of the seal concrete. Two cores shall be taken if only one tremie pipe is used for the placement of the seal concrete in the footing. Four cores shall be taken if more than one tremie pipe is used for the placement of the seal concrete in the footing. After dewatering the cofferdam, the Engineer will inform the Contractor of the location of holes to be cored in the seal concrete in each footing to determine its quality. An accurate log of cores shall be kept and the cores shall be placed in a crate and properly marked showing the footing depth and elevation at each interval of core recovery. The cores, along with three copies of the coring logs, shall be transported undisturbed to the Materials & Tests Bureau, Montgomery, Alabama, for inspection. No further concrete shall be poured inside the cofferdam until approval is received from the Construction Bureau. Because it is necessary to obtain a high percentage of core recovery for visual inspection and compressive strength testing, the core bit used for core drilling shall be warranted by the manufacturer to be capable of coring the strength of concrete in the seal footing. The Engineer may require a new bit or replacement of the core barrel at any time inspection indicates that the equipment is incapable of coring as required. The minimum core diameter shall be 3.0 inches {76 mm}. If the quality of the seal concrete footing is determined to be unacceptable the Engineer may require the drilling of additional cores without compensation, If the seal concrete is unacceptable STRUCTURE FOUNDATIONS 312

the Contractor shall construct another foundation or perform corrective work as required by the Department. This foundation or the corrective work shall be constructed without compensation from the Department. The details of the replacement foundation shall be submitted in accordance with the requirements given in Article 105.02 for Working Drawings. Unless otherwise directed by the Engineer, all footings shall be cored to a point 6 inches {150 mm} above the bottom of the seal concrete footing.

Structural seal footings designated as mass concrete shall meet the requirements found in Subarticle 510.03(d) and Article 510.04.

The class of concrete required for the specific type of work involved shall be in accordance with the provisions of Section 501.

In general, each footing shall be constructed as a monolith. If construction joints are required, they shall be constructed as provided in Section 501.

Concrete surfaces shall be finished in accordance with the provisions of Section 501 for Class 1 with exposed surfaces receiving a Class 2 finish unless otherwise specified by the proposal or by plan requirements.

503.04Method of Measurement

The measurement of the volume of seal concrete in a footing shall be calculated from the following:  L = Length of footing shown on contract plans (feet {meters});  W = Width of footing shown on contract plans (feet {meters});  T = Final approved elevation of the top of the seal footing (feet {meters});  D = Final approved elevation of the bottom of the seal footing (feet {meters});  Vs = Volume of seal concrete for which payment will be made (cubic yards {cubic meters}).  Vs = L x W x ( T - D ) / 27 {Vs = L x W x ( T - D )} Seal concrete outside of these limits of measurement may be required for the construction of a seal concrete footing, depending on the details of construction selected by the Contractor. No direct payment will be made for any seal concrete outside of the footing plan dimensions shown on the contract plans.

When items for cofferdam and pumping for individual piers or bents are provided by the plans and/or proposal, such will be measured in individual lump sum items for the pier or bent designated.

Excavation and backfill when provided by the plans, proposal, or directed will be measured and paid for under the applicable provisions of Sections 214 and 215.

The actual depth of each core hole drilled at the location directed will be measured in feet {meters} to the nearest 0.1 of a foot {meter}.

Concrete ordered and accepted for filling voids, cracks, and crevices, as required in Item

(c)1, will be measured by the cubic yard {cubic meter} delivered to the work site and acceptably

placed, minus any concrete wasted.

503.05Basis of Payment

Accepted seal concrete, used as directed and measured as noted above, will be paid at the contract price, which shall be full compensation for the concrete complete in place exclusive of reinforcing steel.