621.02 Materials.
620.04 Method of Measurement.
The volume of accepted concrete within the neat lines of the structure as shown on the plans or revised at the written direction of the Engineer will be computed in cubic yards {cubic meters}. The method of average end areas will not be used where results obtained differ from those obtained by more accurate mathematical computation. No deduction will be made for the volume of concrete displaced by steel reinforcement, weep holes, conduits, anchor bolts, or for chamfers of less than 3 inch {75 mm} leg measurements. Attention is directed to Section 502 for Reinforcing Steel, and Sections 210 and 214 for Excavation and Foundation Backfill.
620.05 Basis of Payment.
a.Unit Price Coverage . The accepted Minor St ructure Concrete, measured as noted above, will be paid for at the contract unit price bid which shall be full compensation for the concrete complete in place including furnishing all materials (except reinforcing steel), form work, finishing and for all e quipment, tools, labor, and incidentals necessary to complete the item in accordance with plan details and these specifications. In case of modification to an existing structure, the breaking away of the concrete to the approximate lines shown on the plans and the disposal of the broken concrete and the preparation of the retained steel reinforcement for splicing as required shall be considered incidental to the work and the cost thereof absorbed in the unit price bid.
b.Payment will be made under Item No .: 620-A Minor Structure Concrete - per cubic yard {cubic meter} INLETS, JUNCTION BOXES, MANHOLES, AND MISCELLANEOUS DRAINAGE STRUCTURES
621.01 Description.
This Section shall cover the work of furnishing and installing miscellaneous drainage structures including necessary metal frames, grates, covers, etc. in accordance with the plan details and these specifications at the locations and to the grades shown on the plans or directed by the Engineer. The various units will be further designated by type to distinguish shape, size, etc. by plan details. Certain units or portions of units may be constructed of cast -in-place concrete, precast concrete, and/or masonry as specified by plan details. This Section shall also include the furnishing and installing of grates on new or existing structures when the Item of 621 -G is provided on the plans, otherwise, inlet grates are classified as an integral part of the inlet or catch basin. This Section shall also include the furnishing and installing of stilling basins when the Item of 621 -I is provided on the plans.
621.02 Materials.
a.Concrete, Reinforcing Steel and Masonry . Concrete and reinforcing steel for cast -in-place units and for precast units or parts of units not covered by other requirements shall conform to the requirements of Sections 620 and 502. Precast concrete units or portions of units shall conform to the appropriate requ irements of ASTM C 478, and Section 831 unless otherwise provided by plan details or by Department approval. Masonry materials shall conform to the requirements of Section 613 utilizing brick or block meeting the following requirements: Clay or Shale - ASTM C 32 Grade SS, MS, or MM. Concrete brick - ASTM C 55, Type I, Grade N. Concrete block - ASTM C 90, Type I or II, Grade N.
621.03 Construction Requirements.
b.Grates and Grate Seats . Castings shall conform to the requirements of Section 836 with attention directed to Articles 836.04, 836.05, 836.06, and 836.07. They shall be sound, smooth, clean, and free from blisters and other defects and, where necessary, planed to provide flat true surfaces. Welded grates, grate seats, etc. shall be fabricated from ASTM A 36 material, unless otherwi se denoted by plan details. Inlet and outlet pipe shall conform to the appropriate requirements of the section of the specifications covering the kind of pipe to which they are to connect. Grates, grate seats, etc. which are required for existing structures and are formed by welding of rolled or shaped iron shall, unless otherwise specified by plan details, comply with the following: Plates, angles, bars, etc. - ASTM A 36, Pipe - ASTM A 53; Type F, E, or S, black extra strong (X5), hydrostatic test not req uired. Galvanization of grates, grate seats, nuts, bolts, and miscellaneous metal hardware, when specified on the plans, shall be hot -dipped galvanized after fabrication by one of the following methods: Casting, grates, and seats fabricated from rolled, pr essed, or forged steel shapes - ASTM A 123. Nuts, bolts, and miscellaneous hardware - ASTM A 153. The Department has established List I -9, "Inlet Grates and Seats for Drainage Structures and Miscellaneous Fabricated Items". This list is in the Department's manual, "MATERIAL, SOURCES AND DEVICES WITH SPECIAL ACCEPTANCE REQUIREMENTS." Grates, grate seats and related materials shall be furnished by the approved suppliers on this list. Information concerning this list is given in Subarticle 106.01(f) and ALDOT -355.
621.03 Construction Requirements.
a.Excavation . Excavation shall be performed in accordance with the appropriate requirements set forth under Section 214, Structure Excavation and Backfill for Drainage Structures and Minor Structures.
b.Concrete U nits. Concrete units may be either poured- in-place or precast. Construction requirements relative to the two types shall conform to the following:
1.Poured -in-place units: Construction shall conform to the requirements of Section 620.
2.Precast Concrete Units: Holes for connector pipes in base section shall be cast with connector pipe holes of the specific number and dimensions necessary to incorporate the unit into the drainage system as shown by the plans. Should installation conditions require additio nal pipe holes for which no holes were cast, the Contractor may make such holes as necessary provided he performs said work in a manner approved by the Engineer, and he replaces or repairs any damaged unit to the satisfaction of the Engineer. Pipe connecti ons to the base sections shall be made using either concrete or masonry mortar. Precast bases shall be set to within 1/4 of an inch {± 10 mm} of grade on a bed of compacted foundation backfill material approximately 4 inches {100 mm} thick. Sectional precast sections used to form units shall have all joints sealed and wiped clean using one of the appropriate type sealers noted in Subitem 530.03(d)3.a.
c.Masonry . Bricks shall be laid with full mortar joints not more than 1/2 inch {10 mm} thi ck. Courses shall be level and at least one course in every seven shall be a header course, unless otherwise directed. All units shall be plastered on the inside of the unit with not less than 1/2 inch {10 mm} of mortar (same as used in the laying) to a he ight of at least 6 inches {150 mm} above the top of the outfall structure. When specified, the outside of the structure shall be plastered with 1/2 inch {10 mm} of mortar for the height of the masonry. All brick shall be dampened during laying and plasteri ng to insure proper bond with mortar. The masonry shall be cured by approved methods which will insure the mortar has sufficiently set before allowing backfilling operations. When so specified on the plans and/or in the proposal, masonry units may be const ructed of concrete blocks instead of bricks. Applicable construction details shall be the same as for brick masonry.
621.04 Method of Measurement.
d.Inlet and Outlet Pipe . Pipe shall be laid in accordance with the appropriate requirements of the Section of these specifications covering the kind of culvert pipe used. Pipe placed in masonry for inlet or outlet connections shall extend through the walls and beyond the outside surface of the walls a sufficient distance to allow for connections, and the masonry shall be carefully construct ed around them so that there will be no leakage around the outer surface of the pipe. Pipe connections to masonry or precast units shall be made using either concrete or masonry mortar.
e.Placing Castings . Castings shall be set in full mortar beds or oth erwise secured as shown on the plans. The mortar used for setting castings shall conform to Section 611, Mortar for Masonry. Castings shall be set below the finished grade of the pavement about 2 mm.
f.Backfilling . Backfilling shall be performed in accor dance with the appropriate requirements of Sections 210 and 214.
g.Cleaning . All junction boxes, inlets, manholes, and similar structures shall be cleaned of all form material, excess mortar, and all foreign matter and shall be free from such at the time of final inspection and acceptance.
h.Placing of Metal Grates and Seats on Structures . Grates and seat frames shall be set in full mortar beds or otherwise secured to the masonry unit as shown by plan details. Mortar used for setting grates shall confor m to the requirements of Section 611, Mortar for Masonry. Grates installed on drainage units constructed under a previous contract shall be fitted to the unit and affixed to the structure in accordance with the details shown on the plans.
621.04 Method of Measurement.
a.Inlets and Junction Boxes . Inlets and junction boxes will be measured as individual units including footings, bottom slab, walls, cover, lid, grating, etc., of the type, size, and shape shown on the plans. If the height of the base unit is not shown on the plans, 4 feet {1 m} will be used as the height of the base unit. Measurements will be from the top of the bottom slab to the top of the cover, grating, or lid. Structures of greater height will have the additional height measured as noted in Subarticle (c) below.
b.Manholes . Manholes will be measured as an individual unit including footings, bottom slab, walls, cover, lid, grating, etc. of the type, size, and shape shown on the plans except that the maximum height of the base units of th e structure shall be limited to 6 feet {2 m}, measured from the top of the bottom slab to the top of cover, grating, or lid. Structures of greater height will be measured as noted in Subarticle
c.below.
c.Junction Box, Inlet , and Manhole Units . Where s tructures of greater height than the base units noted above are provided by the plans or ordered, measurement for the additional height will be in junction box units, inlet units, or manhole units of the particular type specified by the plans or proposal. Such units will be complete wall sections of the respective type structure measured in increments of 2 feet {600 mm} in height; ordered increments of less than 2 feet {600 mm} will be considered as a complete unit.
d.Item 621-G. When Item 621 -G is provid ed on the plans or proposal, the kind of inlet on which the grate will be used will be shown on the plans and the "Type" grate to be used will be designated on the plans and proposal. The accepted grates will be measured in individual units of each type or dered and accepted.
e.Item 621-I. When Stilling Basins, Item 621 -I, are provided on the plans or proposal, measurement will be as individual units including footings, bottom slab, walls, etc., of the type, size, and shape shown on the plans.
621.05 Basis of Payment.
621.05 Basis of Payment.
a.Unit Price Coverage .
1.The accepted number of junction boxes, inlets, and manholes, measured as provided above, will be paid for at the respective contract unit prices for each, which shall be payment in full for furnishing all mater ials including gratings, covers, and other fittings and for all form work, disposal of surplus material, and for all labor, equipment, tools, and incidentals necessary to complete the work.
2.The accepted number of junction box units, inlet units, and man hole units, measured as provided above, will be paid for at the respective contract unit price for each type, complete in place, which shall be payment in full for furnishing all materials, for all form work, disposal of surplus materials, and for all labo r, equipment, tools, and incidentals necessary to complete the work.
3.The ordered and accepted grates under Item 621 -G, measured as provided above, will be paid for at the respective unit price bid for each type specified. Said unit price shall be full c ompensation for the grate complete in place on the structure and includes furnishing of all materials, fabrication of the grate, installation of the grate, and for all equipment, tools, labor, and incidentals necessary to complete the work.
4.The accepted number of stilling basins, measured as provided above, will be paid for at the respective contract unit price for each type, complete in place, which shall be payment in full for furnishing all materials, for all form work, disposal of surplus materials, and for all labor, equipment, tools, and incidentals necessary to complete the work.
b.Excavation and Backfill . Excavation and backfill will be paid for as provided in Section 214.
c.Payment will be made under Item No.: 621-A Junction Boxes, Type ____ - per each 621-B Junction Box Units, Type ____ - per each 621-C Inlets, Type ____ - per each 621-D Inlet Units, Type ____ - per each 621-E Manholes, Type ____ - per each 621-F Manhole Units, Type ____ - per each 621-G Inlet Grates, Type ____ - per each 621- I Stilling Basins, Type ____ - per each SECTION 622 RESETTING GRATINGS AND COVERS FOR CATCH BASINS, INLETS, AND MANHOLES
622.01 Description.
This Section shall cover the work of raising or lowering the covers or gratings of existing inlets, catch basins, or manholes, all in accordance with plan details and these specifications at the locations shown on the plans or directed.
622.02 Materials.
All new materials used shall be in accordance with the requirements of Section 621, plan details, and Division 800, Materials.
622.03 Construction Requirements.
Heads, covers, and/or gratings of existing manholes, inlets, or catch basins that are raised, lowered, or moved in elevation without moving the structure proper will be considered reset. All work shall be done in a workmanlike manner by competent workmen and the unit re -established in proper working order at its new elevation. Any manhole, inlet, or catch basin heads, covers, gratings, or other material broken, destroyed, lost, or rendered unfit fo r reuse through carelessness, negligence, or improper handling of the work, shall be replaced by the Contractor without extra compensation. Concrete and brick masonry work shall conform to requirements of Sections 620 and 613, respectively. When adjustment s to manholes, inlets, or catch basins require the removal of a portion of the existing facility, the Engineer will designate that portion of the structure to be removed. The removal of
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 504–506 of 934.