651 Page 465651 CONCRETE SIDEWALK
651.1DESCRIPTION
This work consists of constructing sidewalks on a prepared subgrade.
651.2MATERIALS
Materials will conform to the following sections: A.Concrete: Class M6, Section 462. B.Preformed Expansion Joint Filler: Section 860. C.Cushion Material: Cushion material will consist of rock, gravel, or sand; crushed or screened to eliminate material retained on a 1 inch sieve. The material will be free from roots, sod, and lumps of dirt. Not more than 25.0% by weight will pass a #200 sieve. D.Curing Compound: Section 821.
651.3CONSTRUCTION REQUIREMENTS
The foundation will be excavated, shaped, and compacted to a firm, uniform bearing surface. Unsuitable foundation material will be removed and replaced as directed. The foundation will be thoroughly moistened immediately prior to placing concrete. Moisture will be applied without forming pools of water. Cushion material will be placed to the depth specified and satisfactorily compacted. Forms will be made of wood not less than 2 inches nominal thickness or of steel of equal rigidity. Flexible strips may be used on curves. The forms will be securely held to line and grade and will not deviate more than 1/8 inch from an accurate template 10 feet in length. The forms will remain in place until the concrete has hardened to the point that no damage will be done to the concrete during form removal. Damage to the concrete as the result of form removal will be repaired by the Contractor at no additional expense to the Department. Joint and edging tools will have an approved 1/4 inch radius. Immediately after the water sheen has disappeared the concrete will be brushed or broomed to slightly roughen the surface and remove tool marks. Contraction and longitudinal joints will be placed at intervals that will provide approximately square sections. The joints will be formed by a grooving tool or sawing to a depth of at least one third the thickness of the sidewalk. When the sidewalk is greater than 8 feet in width, a longitudinal joint may be required, depending on the thickness of the sidewalk. When a longitudinal joint is required, the Contractor will provide the longitudinal joint at the center and the contraction joints will be adjusted to result in approximately square sections. The maximum length and width of a square section is determined by the following formula: 24 x Thickness of Sidewalk (inches) = Maximum Length & Width of Square Sections (inches) 651 Page 466Expansion joints will be constructed of 1/2 inch preformed expansion joint filler at a maximum spacing of 75 feet or at the locations and of the dimensions specified on the plans. When the concrete sidewalk is placed adjacent to the curb and gutter, the Contractor will place 1/2 inch preformed expansion joint filler longitudinally along the backface of the curb and gutter. When the concrete sidewalk is placed adjacent to other solid fixtures including, but not limited to, buildings, parking lots, driveways, and retaining walls, the Contractor will place a double thickness of preformed expansion joint filler at the back of the sidewalk. All other obstructions will require 1/2 inch preformed expansion joint filler, as directed by the Engineer. In areas where the sidewalk widens at the bridges, 1/2 inch preformed expansion joint filler will be placed transversely across the sidewalk at the beginning of the transition and adjacent to the bridge sidewalk. The expansion joint filler will be placed the full depth of the sidewalk. The Contractor will ensure the expansion joint filler material is securely held in place during concrete placement. Concrete sidewalk will be protected and cured in accordance with Section 460.3 M, except the minimum curing time will be 72 hours. Concrete sidewalk with slopes exceeding the design slopes will be removed and replaced at the Contractor’s expense. After the curing period, the area adjacent to new sidewalk will be filled to the required elevation with suitable material. The material will be compacted to the same degree as the adjacent embankment or ground surface.
651.4METHOD OF MEASUREMENT
Concrete sidewalk will be measured to the nearest foot and the area computed to the nearest square foot.
651.5BASIS OF PAYMENT
Concrete sidewalk will be paid for at the contract unit price per square foot. Payment will be full compensation for excavation other than removal of existing sidewalk as provided for under Section 110. Payment will be full compensation for labor, equipment, tools, backfilling; furnishing and placing materials, including but not limited to, granular material and preformed expansion joint material; and incidentals necessary, including but not limited to, disposal of excavation and discarded materials. 670 Page 467670 DROP INLETS
670.1DESCRIPTION
This work consists of furnishing materials and the construction of drop inlets.
670.2MATERIALS
Materials will conform to the following sections. A.Concrete: Class M6, Section 462. For precast drop inlets cast at a facility regularly producing other precast concrete items under Section 560 or Section 990, the concrete will conform to Section 560. B.Castings: Unless otherwise specified, frames and grates will consist of approved gray iron castings meeting the requirements of AASHTO M 105, Class 35. Grates will fit the frames with which they are to be used. Inaccuracies of bearing will be corrected by machining before use or replaced with new assemblies. C.Steel Reinforcement: Section 1010 . D.Mortar: Mortar will consist of one part Portland cement and two parts mortar sand conforming to Sections 750 and Section 810 respectively. As an alternate, a commercially available grout conforming to Section 460.2 K may be used. E.Curing Compound: Section 821.
670.3CONSTRUCTION REQUIREMENTS
A.General Requirements: Concrete for drop inlets will be proportioned, mixed, hauled, and placed in accordance with Section 462. For precast drop inlets cast at a facility regularly producing other precast items under Section 560, the concrete proportions, slump, and air content will conform to When the foundation for a drop inlet is in new embankment, the embankment will be constructed to an elevation at least 1 foot above the footing before the foundation for the drop inlet is prepared. The foundation will be compacted as specified for the adjacent embankment. Castings will be set in full mortar beds or secured as specified. Castings will be set accurately to the correct elevation so subsequent adjustment will not be necessary. Inlet and outlet pipe connections will be of the same size and kind and will meet the same requirements as the pipe they connect. Pipe sections will be flush on the inside of the structure wall and project outside sufficiently for proper connection with the next pipe section. Masonry will fit neatly and tightly around the pipe. Grouting of the pipe connection may be required as directed by the Engineer if voids exist after form removal.