620MINOR STRUCTURE CONCRETE

500

are attached. In lieu of the bituminous coating, the Contractor may substitute a polymeric coating meeting the requirements specified in Item 850.02(c)2.  Safety grates, when required, shall be fabricated in accordance with plan details.

619.03Construction Requirements

All excavation involved shall be in accordance with the provisions of the Sections for the type pipe involved and Section 214. Backfilling shall be as specified under Sections 210, 214 and the applicable Pipe Culvert Section.

When prefabricated end sections are used, they shall be installed and securely affixed to the pipe line as shown on the plans or directed, all in conformity with the established lines and grades for the structure. When slope paved headwalls are used, they shall be constructed as shown on the plans.

619.04Method of Measurement

The number of end treatments measured for payment will be the actual number of end treatments of the designated size and class, complete in place, on each designated pipe culvert.

619.05Basis of Payment

The ordered and accepted pipe culvert end treatment of the designated class for each size and appropriate type of pipe to which the end treatment is attached, measured as noted above, will be paid for at the contract unit price bid for the end treatment. Such price shall be full compensation for the furnishing of all materials and the installation and construction thereof, except for the items of Structure Excavation and Foundation Backfill, necessary for the complete construction of the end treatment, and for all labor, tools, equipment, and incidentals necessary to complete the work.

619-A ___ inch {mm} * Pipe End Treatment, Class ____ - per each 619-B ___ inch {mm} Span, ___ inch {mm} Rise * Pipe End Treatment, Class ____ - per each * Specify Roadway or Side Drain. MINOR STRUCTURE CONCRETE

620.01Description

This Section shall cover the work of constructing minor concrete structures such as pipe culvert headwalls, inlets and junction boxes, concrete steps, coping walls, and other miscellaneous items. All of which shall be constructed in accordance with the details shown on the plans and these specifications to the lines and grades established by the plans or directed.

620.02Materials

All materials furnished for use shall conform to the requirements of Division 800, Materials, and the following:  Section 501 Structure Concrete  Section 502 Reinforcing Steel

620.03Construction Requirements

The concrete mix used for minor structure work shall be Class A concrete unless otherwise provided by plan details, all in accordance with the appropriate provisions of Section 501.

Excavation and backfill shall be in accordance with the provisions of Sections 210 and 214.

Construction, forming, placing, etc. of the structures shall be in accordance with the requirements given in Section 501. INLETS, JUNCTION BOXES, MANHOLES, AND MISCELLANEOUS DRAINAGE STRUCTURES 501

Attention is directed to the requirement given in Section 501 that all surfaces receive a Class 1 surface finish and that all exposed surfaces receive a Class 2 surface finish, unless otherwise specified in the proposal or by plan requirements. In order to permit proper surface finishing, forms may be removed as soon as the concrete has set sufficiently that form removal will not damage the green concrete, but in no event less than 12 hours after completion of the placing. Immediately after the pouring operations, surfaces not covered by forms shall be covered with one of the curing materials specified in Section 830. Immediately after the removal of the forms, the surface finishing operations noted in Section 501 shall commence, and the curing operations continued for at least 72 hours after the finishing operation, using one of the curing materials specified in Section 830 and the related curing method required with the material used. Failure to apply the initial surface finish or perform the curing operation as noted herein shall be just cause for rejection of the concrete. Removal and replacement of rejected concrete shall be at no additional cost to the Department.

The finished concrete shall be within reasonably close conformity to the lines, grades, and dimensions shown on the plans or directed, and free from objectionable cavities or projections.

620.04Method 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.

620.05Basis of Payment

The accepted Minor Structure 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 equipment, 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.

620-A Minor Structure Concrete - per cubic yard {cubic meter} INLETS, JUNCTION BOXES, MANHOLES, AND MISCELLANEOUS DRAINAGE STRUCTURES

621.01Description

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. INLETS, JUNCTION BOXES, MANHOLES, AND MISCELLANEOUS DRAINAGE STRUCTURES 502

This Section shall also include the furnishing and installing of stilling basins when the Item of 621-I is provided on the plans.

621.02Materials

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 requirements 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.

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 otherwise 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 required. 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, pressed, 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

621.03Construction Requirements

Excavation shall be performed in accordance with the appropriate requirements set forth under

Concrete units may be either poured-in-place or precast. Construction requirements relative to the two types shall conform to the following:

Construction shall conform to the requirements of Section 620.

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 additional 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 connections 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.