SECT-57_INLETS_MANHOLES_AND_JUNCTION_BOXES.docx

SECTION 57 – INLETS, MANHOLES, AND JUNCTION BOXES

Item No. Title

57.1 SCOPE OF WORK

57.2 MATERIALS

57.3 FORMS

57.4 INSTALLATION

57.5 PLACING AND CURING CONCRETE

57.6 FINISHING STRUCTURES

57.1 SCOPE OF WORK

The work specified herein shall consist of constructing inlets, manholes, and junction boxes. These structures shall be made of Portland Cement Concrete and reinforcing steel with the necessary metal frames and gratings, and shall be constructed in conformity with the detailed plans and these specifications. All inlets, manholes, and junction boxes shall meet Florida Department of Transportation (F.D.O.T.) specifications. Masonry construction shall be limited to the completion of doghouses around pipes, adjusting manhole covers, etc., or as approved by the PROJECT ENGINEER. It is the intent of the specifications that structures be constructed of precast concrete or cast-in-place concrete.

57.2 MATERIALS

Concrete shall have a minimum 28 day compressive strength of 4,000 psi, Type III. The mortar for masonry shall be of Type I Portland Cement and sand mixed in the proportions of one part cement to two parts of sand. At the option of the contractor, high early strength cement may be used.

Reinforcing steel shall consist of #4 Rebar installed 12 inches on-center each way in all walls, bases, and tops (where appropriate).

Grates and metal frames shall be cast iron traffic bearing in all rights-of-way and other traffic areas.

All clay brick shall conform to the current ASTM designation C-55, Grade P-II.

57.3 FORMS

Forms for cast-in-place structures shall be built true to line and grade, braced in a substantial and unyielding manner and so designed and constructed that they may be removed without injury to the concrete.

57.4 INSTALLATION

Pipes shall extend through the walls and be flush with the inside wall. Masonry shall be constructed around them neatly. All surfaces at pipe junctions shall be plastered with mortar as specified in Item 57.2, this Section. Plastered areas should not crack and be properly prepared to bond to old surfaces. Masonry inverts are required.

57.5 PLACING AND CURING CONCRETE

For cast-in-place structures, the concrete shall be placed in the forms to the depth shown on the plans and thoroughly vibrated, tamped, and/or spaded. After the concrete has hardened sufficiently, it shall be covered with a suitable material and kept moist for a minimum of seventy-two (72) hours. The concrete shall be protected in a satisfactory manner from the elements until thoroughly cured.

57.6 FINISHING STRUCTURES

For all concrete structures, all fins, and irregular projections shall be chipped off flush with the surface immediately following the removal of the forms. All projecting wires, nails, etc., shall be cut off at least one-half inch under the surface.

All cavities produced by metal spacers, form ties, bolts, honeycomb spots, etc., shall be carefully cleaned, saturated with water, and the carefully painted with mortar. All construction and expansion joints in the completed work shall be left carefully tooled and free from excessive mortar and/or concrete. Joint filler will be left exposed for its full length and display clean edges. Mortar "topping" for upper horizontal surfaces shall not be used.

For all concrete surfaces, which are to receive a surface finish, the CONTRACTOR shall remove the forms and finish the concrete immediately after the concrete has set sufficiently.

All inlets, manholes, and junctions boxes shall be thoroughly cleaned prior to inspection and/or final acceptance.