731Precast Reinforced Concrete Manholes and Drop Inlets

731.1 Description. This work shall consist of furnishing and installing precast concrete manholes and drop

inlets as shown on the plans.

731.2 Material.

731.2.1 All material shall be in accordance with Division 1000, Material Details, and specifically as follows:

Item Section Precast Drainage Units 1033 Concrete Curing Material 1055 Plastic Joint Compound for Vitrified Clay and Concrete Pipe 1057 Tubular Joint Seal 1057 Mortars and Grout 1066

731.2.2 Concrete for footings shall be Class B, Class B-1 or concrete of a commercial mixture in accordance

with Sec 501. Air entrainment will not be required.

731.3 Construction Requirements.

731.3.1 Excavation and Backfilling. Excavation and backfilling for precast reinforced concrete manholes and

drop inlets shall be in accordance with Sec 206.

731.3.2 Placement. Precast concrete manhole and drop inlet sections shall be constructed as shown on plans,

and joints sealed in accordance with Sec 726.

731.3.3 Footings. Footings shall be constructed as shown on the plans. Concrete shall be float finished and shall

be cured in accordance with Sec 502. Forms will not be required.

731.4 Method of Measurement.

731.4.1 Final measurement of precast concrete manholes and drop inlets will not be made except for authorized

changes during construction or where appreciable errors are found in the contract quantity. Where required, measurement of precast concrete manholes and drop inlets, complete in place, will be made to the nearest foot as shown on the plans. The revision or correction will be computed and added to or deducted from the contract quantity. The depth of the structure will be the vertical distance from the top of the uppermost precast section to the invert flowline.

731.4.2 Final measurement for excavation will not be made except for authorized changes during construction

or where appreciable errors are found in the contract quantity. Where required, excavation will be measured and paid for in accordance with Sec 206. The revision or correction will be computed and added to or deducted from the contract quantity.

731.5 Basis of Payment.

731.5.1 The accepted quantities of precast manholes and drop inlets, complete in place, including any necessary

cutting or joining new pipe or existing pipe to the structure unless otherwise specified, will be paid for at the contract unit price for each of the pay items included in the contract.

731.5.2 No direct payment will be made for, backfilling except as specified in Sec 206, footing concrete, steps,

weep holes, including excavation, permeable granular backfill, 4-inch drain tile, screen for inlet or any other work incidental thereto.