286 ALASKA 2020 SECTION 603 CULVERTS AND STORM DRAINS
603-1.01 DESCRIPTION . Construct or reconstruct culverts and storm drains (pipe), to the lines
and grades shown on the Plans.
603-2.01 MATERIALS. Use materials that conform to the following:
Bedding and Backfill Subsection 204- 2.01 Joint Mortar Subsection 705- 2.04 Flexible Watertight Gaskets Subsection 705- 2.05 Non- Reinforced Concrete Pipe Subsection 706- 2.01 Reinforced Concrete Pipe Subsection 706- 2.02 Corrugated Polyethylene Pipe (Unperforated) Subsection 706- 2.07 Corrugated Steel Pipe and Pipe Arches Subsection 707- 2.01 Bituminous Coated Corrugated Steel Pipe and Pipe Arches Subsection 707- 2.02 Corrugated Aluminum Pipe Subsection 707- 2.03 When Item 603.0017.____ , Pipe, is listed in the bid schedule, furnish either Corrugated Steel Pipe (CSP), Corrugated Aluminum Pipe, Reinforced Concrete Pipe, or Corrugated Polyethylene Pipe. End Sections for Metal Pipe must be of the same material as the pipe. When extending in- place metal culverts and/or reattaching end sections with dissimilar metal, provide an electrical insulating material to separate the dissimilar materials. The insulating material must be at least 1/16 inch thick and be approved by the Engineer. Select pipe for each installation which meets or exceeds the requirements shown on t he Plans for height of cover. CONSTRUCTION REQUIREMENTS
603-3.01 GENERAL. Excavation, bedding, and backfill must conform to the requirements of
Subsections 204- 2.01 and 204- 3.01, and the details on the Plans.
603-3.02 LAYING PIP E. Begin the pipe laying at the downstream end of the pipe. Keep the
lower segment of the pipe in contact with the shaped bedding throughout its full length. Place bell or groove ends of rigid pipe and outside circumferential laps of flexible pipe facing upstream. Lay paved or parti ally lined pipe so that the longitudinal center line of the paved segment coincides with the flow line. Install elliptical conduit and circular conduit reinforced with other than a full circular cage or cages so the orientation of a vertical plane through the longitudinal axis of the conduit does not vary more than 5 degrees from the design orientation. Repair damaged metallic coating on metal pipe according to AASHTO M 36.
603-3.03 Joining Pip E.
1.Rigid Pipe . Use either bell and spigot or tongue and groove joints. Join pipe sections so that the ends are fully entered and the inner surfaces are reasonably flush and even. Use one or more of the following joint materials, or any other if approved:
a.Portland cement mortar
b.Portland cement grout
c.Rubber gaskets 287 ALASKA 2020 d. Oaku m and mortar
e.Oakum and joint compound
f.Coupling bands
g.Preformed plastic sealing compound Make mortar joints using an excess of mortar to form a bead around the outside of the pipe. Finish the joint smooth on the inside. For grouted joints, use molds or runners to retain the poured grout. Install rubber ring gaskets to form a flexible, watertight seal. When using oakum, caulk the joint and then seal it with the specified material. When using portland cement mixtures, protect the completed joints against rapid drying using suitable covering material.
2.Metal Pipe. Join metal pipe firmly using one of the following types of coupling bands. Use bands that are no more than two nominal sheet thicknesses lighter than the pipe being joined, and in no case more than 0.052 inches lighter.
a.Primary Band . Furnish and install corrugated bands so that the band corrugations match and conform to the corrugations of the pipe. Conform to the following guidelines:
1.The gap between the pipe being joined is in the center of the band and is no wider than one corrugation width.
2.Bands for 12- inch through 30 inch diameter pipe are at least 12 inches wide.
3.Bands for pipe with diameters greater than 30 inches are at least 22 inches wide.
b.Secondary Band. Use this band only where it is not phys ically possible to use primary bands, such as on field- cut pipe ends, joining new pipe to existing pipe, etc. Furnish and install deformed metal sheet bands (dimple bands) so that the projections match and are the same depth as the pipe corrugations. Form these projections in circumferential rows with one projection for each corrugation of the helical pipe. Conform to the following guidelines:
1.The gap between the pipe being joined is in the center of the band and is no wider than 2 inches.
2.Bands for 12- inch diameter pipe are at least 12 inches wide and have one circumferential row of projections for each pipe end being joined.
3.Bands for pipe with diameters greater than 12 inches are at least 24 inches wide and have two circumferential rows of projections for each pipe end being joined.
4.Furnish and install these bands with a gasket that resists infiltration and leakage.
3.Polyethylene Pipe. Ensure that polyethylene pipe couplings are corrugated to match the pipe corrugations and that their width is not less than one half the nominal pipe diameter. Furnish all bolted connections on coupling bands with cutwashers placed between the nut and the angle bracket or use nuts with integral washers. Take up any pipe that is out of alignment, unduly settled, or damaged and re-lay or replace it. 288 ALASKA 2020 603-4.01 METHOD OF M EASUREMENT. See Section 109, and as follows:
1.Culvert Pipe. The length of pipe, measured in place, along the invert.
2.Pipes for Storm Drains . The length of pipe, measured in place, along the invert, from center to center of structures. No deduction will be made for length through inlets, catch basins, or manholes.
3.End Sections . The number of units installed.
4.Branch Connections and Elbows . The number of units installed when listed on the bid schedule. Included in the length measurement for pipe when not listed on the bid schedule.
603-5.01 BASIS OF PA YMENT. Coupling bands and other items necessary for the proper joining
of the sections are subsidiary. Excavation, bedding, and backfill are paid for under Section 204. Payment will be made under: PAY ITEM Item Number Item Description Unit 603.0001.____ CSP ___ Inch LF 603.0002.____ ___ Inch CSP Arch LF 603.0003.____ End Section for CSP ___ Inch Each 603.0004.____ End Section for ___ Inch CSP Arch Each 603.0005._ ___ Bituminous Coated CSP ___ Inch LF 603.0006.____ Bituminous Coated CSP Arch ___ Inch LF 603.0007.____ End Section for Bituminous Coated CSP ___ Inch EACH 603.0008.____ End Section for Bituminous Coated CSP Arch ___ Inch EACH 603.0009.____ Corrugated Aluminum Pipe ___ Inch LF 603.0010.____ ___ Inch Corrugated Aluminum Pipe Arch LF 603.0011.____ End Section for Corrugated Aluminum Pipe ___ Inch EACH 603.0012.____ End Section for ____ Inch Corrugated Aluminum Pipe Arch EACH 603.0013.____ Reinforced Concrete Pipe, ___ Inch, Class ___ LF 603.0014.____ Reinforced Concrete End Section, ___ Inch EACH 603.0015.____ Elbow, (Type & Size) EACH 603.0016.____ Branch Connection, (Type & Size) EACH 603.0017.____ Pipe ___ Inch LF 603.0018.____ Bituminous Coat ed Paved Invert CSP __ Inch, __ Gauge LF 603.0019.____ ___ Inch Pipe Arch LF 603.0020.____ End Section for Pipe ___ Inch EACH 603.0021.____ Corrugated Polyethylene Pipe ___ Inch LF 603.0022.____ End Section for Corrugated Polyethylene Pipe ___ Inch EACH 289 ALASKA 2020 SECTION 604 MANHOLES AND INLETS
604-1.01 DESCRIPTION . Construct, reconstruct, relocate, or adjust manholes and inlets.
604-2.01 MATERIALS. Use materials that conform to the following:
Concrete Section 550, Class B Clay or Shale Brick Subsection 70 4-2.01 Concrete Brick Subsection 704- 2.02 Concrete Masonry Block Subsection 704- 2.03 Joint Mortar Subsection 705- 2.04 Flexible Watertight Gaskets Subsection 705- 2.05 Reinforcing Steel Subsection 709- 2.01 Precast Concrete Manhole Sections Subsection 712- 2.05 Frames, Grates, and Covers, Subsection 712- 2.06 Corrugated Metal Units Subsection 712- 2.07
604-3.01 CONSTRUCTIO N REQUIREMENTS. Install precast concrete manholes consisting of a
base, risers, cone or flat top; with steps, pipe boots, frame and cover as s hown on the Plans. Use flexible watertight gaskets between concrete sections. Tighten watertight boots over all pipes, then grout pipes in place. Install inlets consisting of a precast concrete catch basin box, risers, metal frame and grate as shown on th e Plans. Grout pipes into place. Construct cast -in-place concrete manhol es and inlets to conform to the requirements of Section 550 and the details shown on the Plans. Use full mortar joints no more than 1/2 inch wide. Set metal frames in full mortar bed. When specified, plaster the outside face of concrete structures with a 1/2 inch thick cement -sand mortar coat. Cure exposed surfaces of concrete and masonry with wet burlap for at least 48 hours. Fit each pipe section flush on the inside of the struc ture wall and to project far enough outside to connect properly with the next pipe section. Fit masonry neatly and tightly around the pipe. Construct invert channels in all manholes used for sanitary or combined sanitary and storm sewers. Construct channels to be smooth and semicircular to conform to the inside of the adjacent sewer sections. Make changes in flow direction along a smooth curve with as large a radius as the manhole size permits. Make gradual and even changes in channel size and grade. Form invert channels by using any of the following methods:
1.Directly in manhole concrete base
2.Built up with brick and mortar
3.Laying half tile in concrete
4.Breaking out the top one- half of full sections of pipe, laid through the manhole, after the surrounding concrete has hardened
Source: Alaska Standard Specifications for Highway Construction, 2020 Edition. Pages 314–316 of 584.