Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects. FP-74

reasonably close conformity with the lines and grades shown on the plans or established by the Engineer.

Materials

604.02 Materials. Concrete for these structures shall meet the requirements of Section 602 Minor Concrete Structures. Other materials shall meet the requirements specified in the following subsections:

Frames, grates and covers, and ladder rungs.

712.07

Reinforcing steel____

709.01

Precast concrete units.

712.06

Construction Requirements

604.03 Construction Requirements. Concrete construction shall conform to the requirements for structural concrete. When shown on the plans, concrete in slab covers, and all other portions of the structure exposed in the final work, shall be colored by the addition of sufficient emulsified carbon black to give the shade required by the Engineer. To determine the quantity of carbon black required, the Contractor, if so directed by the Engineer shall cast, at his own expense, five sample blocks of concrete 6 by 6 by 4 inches (152 by 152 by 102 mm), adding varying quantities as directed so that the required shade may be obtained. The finished surface shall present a neat and smooth appearance and shall have a uniform color.

Joints for precast concrete manhole sections shall be made with portland cement mortar, rubber gaskets, mastic joint fillers, by a combination of these types, or any other approved type, as may be specified. The completed mortar joint shall be formed with a bead on the outside and finished smooth on the inside of the sections, and suitably cured. The rubber ring gaskets shall be installed so as to form a flexible watertight seal. The mastic joint filler shall be applied in accordance with the manufacturers recommendations so as to form a watertight seal.

Metal frames shall be set in full mortar bed. Pipe sections smaller in diameter than the structure shall be flush on the inside of the structure wall and project outside sufficiently for proper connection with next pipe section. Pipe sections larger in diameter than the structures shall

be constructed as monolithic tee sections. Masonry shall fit neatly and tightly around the pipe.

When grade adjustment of existing structures is specified, the frames, covers, and gratings shall be removed and the walls reconstructed as required. The cleaned frames shall be reset at the required elevation. Upon completion, each structure shall be cleaned of any accumulations of silt, debris, or foreign matter of any kind and shall be kept clear of such accumulation until final acceptance of the work.

Excavation and backfill shall be done in accordance with Section 206. 604.04 Method of Measurement. Manholes, inlets and catch basins, both new and reconstructed as applicable, will be measured by the unit. Manholes will be divided into two types.

Type 1: Structures connected to pipe 42" (1.07 m) or less in diameter regardless of the pipe skew.

Type 2: Structures connected to pipe 48" (1.22 m) in diameter or larger, regardless of the pipe skew.

In addition, each Manhole that exceeds 6 feet (1.83 m) in depth will be measured for additional payment known as Manhole Additional Depth. This additional depth, measured in linear feet shall be that depth exceeding, and not including that upper 6 feet (1.83 m). Manhole Additional Depth shall be classed as follows:

Class 1: Manhole Additional Depth, Class 1, shall apply to each Manhole 10 linear feet (3.05 m) or less in depth.

Class 2: Manhole Additional Depth, Class 2, shall apply to each Manhole exceeding 10 linear feet (3.05 m) but not exceeding 20 linear feet (6.10 m) in depth.

Class 3: Manhole Additional Depth, Class 3, shall apply to each Manhole exceeding 20 linear feet (6.10 m) but not exceeding 30 linear feet (9.14 m) in depth.

Class 4: Manhole Additional Depth, Class 4, shall apply to each Manhole exceeding 30 linear feet (9.14 m) but not exceeding 45 linear feet (13.72 m) in depth.

604.05 Basis of Payment. The accepted quantities of manholes, inlets, and catch basins will be paid for at the contract unit price per each complete in place. Manhole Additional Depth of the appropriate class, measured as indicated above, will be paid for at the contract price per linear foot. Such payments shall be full compensation for furnishing all castings, fittings and other appurtenances called for on the plans to complete the item; for making necessary pipe connections regardless of skew; for all materials, forms, and for the disposal of surplus material. Payment will be made under:

Excavation, bedding, backfill, replacing pavement where required, reinforcing steel and disposal of surplus material will not be measured and paid for separately, but shall be included in the Contract Price for each structure unless otherwise specified.

Section 605.-UNDERDRAINS

Description

605.01 This work shall consist of constructing underdrains using pipe and granular filter material, underdrain pipe outlets, and blind drains using granular material in accordance with these specifications and in reasonably close conformity with the lines and grades shown on the plans or established by the Engineer.

Materials

605.02 Material. Materials shall meet the requirements specified in the following subsections of Section 700-Materials.

Perforated Plastic Pipe for Underdrain

706.17

Slotted Poly Vinyl Chloride Pipe.

706.17

Corrugated Iron or Steel Pipe for Underdrains

707.04

605.03 Pipe Installation. Trenches shall be excavated to the dimensions and grades required by the plans or as directed. A minimum

6-inch (152 mm) bedding layer of granular backfill material shall be placed and compacted in the bottom of the trench for its full width and length.

Perforated pipe shall normally be placed with the perforations down except that the last 10 feet (3.05 m) at the outlet end which may be non-perforated pipe. The pipe sections shall be joined securely with the appropriate coupling fittings or bands.

Non-perforated pipe shall be laid with the bell end up-grade and with open joints wrapped with suitable material to permit entry of water, or unwrapped as may be specified. Upgrade end sections of all subdrainage pipe installations shall be closed with suitable plugs to prevent entry of soil materials.

After the pipe installation has been inspected and approved, granular backfill material shall be placed to a height of 12 inches (305 mm) above the top of pipe. Care shall be taken not to displace the pipe or the covering at open joints. The remainder of the granular backfill material shall then be placed and compacted in 6 inch (152 mm) maximum layers to the required height. Any remaining portion of trench above the granular backfill shall be filled with either granular or impervious material, as may be specified, and thoroughly compacted.

605.04 Underdrain Outlets. Trenches for underdrain outlets shall be excavated to the width and depth shown on the plans or as otherwise indicated. Pipe shall be laid in the trench with all ends firmly joined by the applicable methods and means. After inspection and approval of the pipe installation the trench shall be backfilled in accordance with subsection 603.08. Each outlet end of the subdrainage system shall be marked in accordance with plan details.

605.05 Blind Drains. Trenches for blind drains shall be excavated to the width and depth shown on the plans. The trench shall be filled with granular backfill material of the type and to the depth required by the plans. Any remaining upper portion of trench shall be filled with either granular or impervious material in accordance with subsection 603.08.

Method of Measurement

605.06 Underdrains and outlets will be measured by the linear foot for pipe of the type and size specified. Blind drains will be measured by the linear foot including all excavation and backfill material required.

Granular backfill material, when specified in the contract as a pay item will be measured in place by the cubic yard, completed and accepted. Cross sectional measurements will not exceed the neat dimensions shown on the plans or directed by the Engineer.

Excavation for underdrain pipe will be measured and paid for as provided in Section 206.

605(1)

605(2)

605(3)

Basis of Payment

605.07 The accepted quantities of pay items from the list below which appear in the bid schedule, determined as provided above, will be paid for at the contract unit prices therefor.

Payment will be made under:

Pay item