(A) General. The sidewalk and sidewalk aprons shall be constructed of Class X concrete mixed in accordance with the requirements of the applicable paragraphs of § 504.
(B) Subgrade preparation. The subgrade shall be tamped or rolled until thoroughly compacted. At locations where sidewalk is constructed at entrances, the sidewalk shall be thickened to the thickness of the adjacent entrance or driveway pavement. This work shall be considered as incidental, and no additional compensation will be allowed.
(C) Forms. Side forms shall be of lumber of not less than two-inch nominal thickness or of steel of equal rigidity. They shall be held securely in place by stakes or braces, with the top edges true to line and grade. Forms for the sidewalk aprons shall be set so that the slab will have a uniform fall between the sidewalk proper and the curb grade.
(D) Placing and finishing.
(1) The subgrade shall be moistened just before the concrete is placed. The concrete shall be placed in successive batches for the entire width of the slab, struck off, mechanically vibrated and finished to a true and even surface with floats and trowels. The final troweling shall be done with a steel trowel, leaving a smooth, even surface. After the water sheen has disappeared, the surface shall be given a final finish by brushing with a whitewash brush. The brush shall be drawn across the sidewalk at right angles to the edges of the walk, with adjacent strokes slightly overlapping, producing a uniform, slightly roughened surface with parallel brush marks.
(2) The surface shall be divided by grooves constructed at right angles to the centerline of the sidewalk. These grooves shall extend to one-fourth the depth of the sidewalk, shall be not less than one-eighth inch and not more than one-fourth inch in width, and shall be edged with an edging tool having a one-fourth inch radius. No slab shall be longer than five feet nor less than four feet on any one side, unless otherwise ordered by the Engineer. The edges of the slabs shall be edged as described above.
(E) (1) Expansion joints. Expansion joints of the thickness specified below shall consist of preformed joint filler. The top of the joint shall be placed one-fourth inch below the surface of the sidewalk.
(2) Three-fourths inch thick expansion joints. Expansion joints three-fourths inch thick shall be placed between the sidewalk and all structures, such as light standards, traffic light standards, traffic poles and subway columns which extend through the sidewalk, and shall be placed at intervals of not more than 50 feet in the sidewalk. Where the sidewalk is constructed adjacent to pavement or curb having expansion joints, the expansion joints in the sidewalk shall be placed opposite the existing expansion joints as nearly as practicable. Expansion joints shall also be placed where the sidewalk abuts existing sidewalks, between driveway pavement and sidewalk, and between sidewalk and curbs where the sidewalk abuts a curb.
(F) Curing and protection. Curing and protection shall be in accordance with Article 625.01.
(G) Backfill. After the concrete has been cured, the spaces along the edges of the sidewalk shall be backfilled to the required elevation with approved material. The material shall then be compacted until firm, and the surface neatly graded.
(H) Disposal of surplus material. Surplus or waste material resulting from the sidewalk construction operations shall be disposed of by the contractor, at his or her own expense.
(I) Method of measurement. Portland cement concrete sidewalk shall be measured in place, and the area shall be computed in square feet.
(2000 Code, § 98.09) Penalty, see § 98.99