The weight of steel grid flooring will be computed separately.

(c) Castings.-The weight of castings will be computed from the dimensions shown on the approved drawings, deducting for open holes. To this weight will be added 5 percent allowable for fillets and overruns. Scale weights may be substituted for computed weights in the case of castings of small complex parts for which accurate computations of weight would be difficult.

(d) Miscellaneous.—The weight of erection bolts, shop and field paint, galvanizing, and boxes, crates, and other containers used for shipping, together with sills, struts, and rods used for supporting members during transportation, bridge hardware as defined in subsection 716.02 excluding steel plates and bearings, connectors used for joining timber members, nails, spikes, and bolts, except anchor bolts will be excluded.

(e) Rivet heads.-The weight of all rivet heads, both field and shop, will be assumed as follows:

(f) High-strength bolts.—High-strength steel bolts will be considered, for the purpose of payment, the same as rivets of the same diameter, with the weight of the bolt heads and nuts the same as the corresponding rivet heads.

(g) Welds.-The weight of shop and field fillet welds will be assumed as follows:

The weight of other welds will be computed on the basis of the theoretical volume from dimensions of the welds, with an addition of 50 percent to the weight as an allowance for

overrun.

(h) Other items.-The quantities of other contract items which enter into the completed and accepted structure will be measured for payment in the manner prescribed for the items involved.

555.27 Lump Sum Basis. Lump sum will be the basis of payment unless noted otherwise in the bidding documents. No measurements of quantities will be made, except as provided in subsections 109.02 and 555.28(d).

555.28 Structural Steel:,

Basis of Payment

(a) Furnished, fabricated, and erected.-The quantity, determined as provided above, will be paid for at the contract unit price per pound for "Structural steel, furnished, fabricated, and erected," which price and payment will constitute full compensation for furnishing, galvanizing, fabricating, radiographing, magnetic particle inspection, delivering, erecting ready for use, and painting all steel and other metal and for all labor, equipment, tools, and incidentals necessary to complete the work, except as provided in subsections 555.29, .30, and .31.

(b) Furnished and fabricated.-When a quantity and unit price for "Structural steel, furnished and fabricated" are shown in the bid schedule, the quantity, determined as provided above, will be paid for at the contract unit price per pound, which price and payment will be full compensation for, furnishing, galvanizing, fabricating, radiographing, magnetic particle inspection, shop painting, and delivering the structural steel and other metal free of charges at the place designated in the special provisions and for all labor, equipment, tools, and incidentals necessary to complete the work, save erection and except as provided in subsections 555.29, .30, and .31.

(c) Erected. When a quantity and unit price for "Structural steel, erected" are shown in the bid schedule, the quantity, determined as provided above, will be paid for at the said contract unit price per pound, which price and payment will be full compensation for unloading all the structural steel and other metal, payment of any demurrage charges, transporting to the bridge site, erecting, magnetic particle inspection and radiographing, complete ready for use, including furnishing and applying the field paint, and for all labor, equipment, tools, and incidentals necessary to complete the work, save furnishing and fabrication, and except as provided in subsections 555.29, .30, and .31.

(d) Lump sum.-When the bid schedule calls for a lump sum price for "Structural steel, furnished, fabricated, and erected," the item will be paid for at the contract lump sum price, which price and payment will be full compensation for furnishing, fabricating, and erecting material and for all work hereinbefore prescribed in connection therewith, including all labor, tools, equipment, and incidentals necessary to complete the work, except as provided in subsections 555.29, .30, and .31.

The estimate of the weight of structural steel shown on the plans is approximate only and no guarantee is made that it is the correct weight to be furnished. No adjustment in the contract price will be made if the weight furnished is more or less than the estimated weight. If changes in the work are ordered by the Engineer, which vary the weight of steel to be furnished, the lump sum payment will be adjusted as follows.

The value per pound of the increase or decrease in weight of structural steel involved in the change will be determined by dividing the contract lump sum amount by the estimate of weight shown on the plans. The adjusted contract lump sum payment will be the contract lump sum amount plus or minus the value of the steel involved in the change, and no additional compensation will be made on account of said change.

Full-size members which are tested in accordance with the specifications when such tests are required by the contract, will be paid for at the same rate as for comparable members in the structure. Members which fail to meet the contract requirements, and members rejected as a result of tests, will not be paid for.

555.29 Material Considered as Structural Steel. For the purpose of subsection 555.28, and unless otherwise shown on the plans, castings, forgings, special alloy steels, and steel plates, wrought iron, and structural shapes of expansion joints and pier protection will be considered as structural steel, except that when quantities and unit prices for certain alloy steels, forgings, castings, or other specific categories of metal are called for in the bid schedule, the weight of such selected material, determined as provided above, will be paid for at the respective contract unit price per pound for "Structural steel (alloy steel forgings, casting, and/or other category), furnished and fabricated, and erected" or "Structural steel (~~), furnished and fabricated," as the case may be, and as named in the bid schedule.

555.30 Other Items. The quantities of all other contract items which enter into the completed and accepted structure will be paid for at the contract unit prices for the several pay items as prescribed for the items involved.

555.31 Payment as Reinforcing Steel. When the bid schedule does not contain a pay item for structural steel, the quantities of metal drains, scuppers, conduits, ducts, and structural shapes for expansion joints and pier protection, measured as provided above, will be paid for as reinforcing steel under Section 554.

Payment will be made under:

Pay item

555(1) Structural steel, furnished, fabricated and erected...

Pay unit
Pound.

555(7) Structural steel, furnished, fabricated, and erected.... .... Lump sum. Where separate payment is to be made for certain metals or for certain particular components, other than under the general provision for structural steel, designation of those particular cases will be inserted in the spaces provided in the pay names for items 555(2), 555(4), or 555(6), as the case may be.

Section 556.-BRIDGE RAILING

Description

556.01 Scope. This work shall consist of bridge railing of the material or combination of materials shown on the plans, constructed in reasonably close conformity with these specifications, and to the lines, grades, and dimensions shown on the plans or established by the Engineer.

556.02 Classification. Bridge railings will be classified as Concrete Bridge Railing, Steel Bridge Railing, Aluminum Bridge Railing, or Timber Bridge Railing in accordance with the predominating material contained in each.

Materials

556.03 Concrete. The materials for concrete shall conform to the applicable requirements prescribed in Section 552.

556.04 Reinforcing Steel. Reinforcing steel shall conform to the requirements prescribed in Section 554.

556.05 Steel. Structural steel, consisting of steel and iron plates, shapes, pipes, fittings, and castings shall conform to the requirements of Section 555.

556.06 Beam Type Steel Railing. Beams, fastenings, and bolts shall conform to the requirements of Sections 606 and 555, as applicable.

556.07 Aluminum Alloy. Aluminum alloy shall conform to the requirements of the following subsections:

556.08 Timber. Timber shall conform to the requirements of Section 557. 556.09 Paint. Paint shall conform to the requirements of Section 708, as designated in the special provisions or on the plans.

Construction Requirements

556.10 General. Bridge railing shall be constructed to the line and grade shown on the plans and shall not reflect any unevenness in the structure. Unless otherwise specified, all railing posts shall be vertical. Railing shall not be placed on a span until centering or falsework has been removed, rendering the span self-supporting.

556.11

Concrete Railing. All concrete shall be of the class or classes shown on the plans and all concrete construction shall conform to the requirements of Section 552.

556.12 Steel Railing. Erection of steel railing shall conform to the applicable requirements of Section 555 and Section 606.

556.13 Aluminum Railing. The fabrication and erection of aluminum railing shall conform to the requirements of Section 555 subject to the following amendments and additions: (a) Cutting.-Material -inch thick or less may be cut by shearing, sawing, or milling. Material over 1⁄2-inch thick shall be sawed or milled.

Cut edges shall be true and smooth and free from excessive burrs or ragged breaks. Reentrant cuts shall be filleted by drilling prior to cutting.

Flame cutting will not be permitted.

(b) Bending.-Material may be heated to a temperature not exceeding 400°F for a period not exceeding 30 minutes to facilitate bending, unless cold bending is required to retain the original mechanical properties of the material furnished.

(c) Rivet and bolt holes.-Rivet and bolt holes shall be drilled to finished size or subpunched smaller than the nominal diameter of the fastener and reamed to size. The amount by which the diameter of a subpunched hole is smaller than that of the finished hole shall be at least one-quarter the thickness of the piece. The finished diameter of holes shall be not more than 7 percent greater than the nominal diameter of the fastener except:

(1) Slotted bolt holes to take care of expansion shall be provided as called for on the plans.

(2) Anchor bolt holes may be up to 25 percent greater than the nominal bolt diameter with a maximum of 1/2-inch greater than the nominal bolt diameter.

(d) Contact with other materials.-Where aluminum alloys come in contact with other metals, the contacting surfaces shall be thoroughly coated with an aluminum-impregnated calking compound, or a synthetic rubber gasket may be placed between the two surfaces. Aluminum alloys shall not be placed between the two surfaces. Aluminum alloys shall not be placed in contact with copper, copper base alloys, lead, or nickel.

Where aluminum alloys come in contact with concrete or stone the contacting surfaces shall be thoroughly coated with an aluminum-impregnated calking compound. When bond between aluminum and concrete is desired, the aluminum shall be coated with zinc-chromate paint and allowed to dry before installation.

Where aluminum alloys come in contact with wood, the contacting surface of the wood shall be given three coats of paint as provided in the applicable provisions of subsection 555.24 and the contacting aluminum surface shall be coated with an approved aluminum calking compound.

556.14 Timber Railing. Erection of timber railing shall be in conformity with the requirements of Section 557.

556.15 Painting. All steel railing, except beam type railing, shall be cleaned and given one primer coat and two field coats of paint in conformity with the requirements of subsections 555.22 through 555.24. Beam type railing shall be painted in conformity with the requirements of Section 606. If galvanizing is shown on the plans in lieu of painting; the requirements of AASHTO M111 or ASTM A525 shall apply. Timber shall be painted with three coats of white lead paint in conformity with the requirements of subsection 555.24.

Method of Measurement

556.16 The quantity to be paid for under this item will be the number of linear feet of bridge railing of the several types, complete in place and accepted, measured along the line and grade of the railing from center to center of metal end posts. It will include all work constructed above the top of the curb and all fastenings and anchors required to attach the railing to the structure. It will include that portion of reinforcement steel for railing which

extends into the curb. Lump sum measurement, if called for in the bid schedule, will be in accordance with subsection 109.02.

Basis of Payment

556.17 When the bid schedule contains an estimated quantity for any of the pay items below, the quantity, determined as provided above, will be paid for at the contract price per pay unit or lump sum respectively, for each of the particular pay items listed below that is shown in the bid schedule, which price and payment will be full compensation for the work prescribed in this section. When the plans or special provisions provide for the construction of bridge railing for which the bid schedule contains no estimated quantity or lump sum under any one of the pay items below, such railing will be considered as an integral portion of the structure to which it is attached and will be paid for as provided under the applicable section covering the bridge construction.

557.01 This work shall consist of timber structures and the timber portions of composite structures, constructed in reasonably close conformity with the lines, grades, dimensions and designs shown on the plans or ordered in writing by the Engineer.

It will include the furnishing, preparing, erecting, and painting of structural timber of the stress values, sizes, and dimensions specified, treated or untreated as called for in the bid schedule. Also included will be any required yard lumber of the sizes and grades specified and all hardware, as shown on the plans or ordered by the Engineer.

Materials

557.02 Materials shall meet the requirements of the following subsections:

Structural Shapes, Rods, and Plates. All structural shapes, rods, and plates shall be of structural steel or wrought iron, as specified or indicated on the plans, meeting the requirements prescribed in Section 555. All eyebars and castings shall conform to the requirements therefore prescribed in Section 555. No welds will be permitted in truss rods, or in main members of trusses or girders.

Construction Requirements

557.03 Workmanship. None but experienced bridge carpenters shall be employed and all framing shall be true and exact. Unless otherwise specified, nails and spikes shall be driven