303-5.1.1 General. Concrete curbs, walks, gutters, cross gutters, alley intersections, access ramps, and driveways shall be constructed of portland cement concrete of the class and other requirements prescribed in 201-1. The finish coat to be applied to curbs shall consist of Class "B" mortar prepared as prescribed in 201-5.1. Subgrade preparation shall conform to the requirements of 301-1.

Unless otherwise specified on the Plans, and except as otherwise prescribed in 303-5.1.3 under the heading "Driveway Entrances", the minimum thickness of walks shall be 3 inches. The thickness of gutters, cross gutters, alley intersections, access ramps, and driveway aprons shall be as shown on the Plans.

303-5.1.2 Drainage Outlets Through Curb. Where existing building drains occur along the line of work, the new curb shall be suitably sleeved to provide for such drains. Similar sleeves shall be installed to serve low areas on adjacent property where drainage has been affected by the work.

The location and size of the sleeves and construction of connecting sidewalk drains shall be in accordance with 306-7.

303-5.1.3 Driveway Entrances. Driveway entrances shall be provided in new curb at all existing driveways along the line of the work, at locations shown on the Plans, and at such other locations as may be designated by the Engineer.

The fully depressed curb opening at driveway entrances shall be 1 inch above gutter flowline at the curb face. The top of the fully depressed portion of the curb shall be finished to a transverse slope toward the gutter of 3/4 inch.

Where walk is to be constructed across driveways to commercial establishments, the thickness thereof shall be 6 inches unless otherwise specified or indicated on the Plans. At residential driveways, the thickness of the walk will be 4 inches unless otherwise specified.

303-5.2.1 Standard Forms. Form material shall be free from warp, with smooth and straight upper edges, and if used for the face of curb, shall be surfaced on the side against which the concrete is to be placed. Wooden forms for straight work shall have a net thickness of at least 1 1/2 inches. Metal forms for such a work shall be of a gage that will provide equivalent rigidity and strength. Curb face forms used on monolithic curb and gutter construction shall be of a single plank width when the curb face is 10 inches or less, except for those used on curb returns. All forms used on curb returns shall be not less than 3/4 inch in thickness, cut in the length and radius as shown on the Plans, and held rigidly in place by the use of metal stakes and clamps. The curb face form shall be cut to conform exactly with the curb face batter as well as being cut to the required length and radius. Forms shall be of sufficient rigidity and strength, and shall be supported to adequately resist springing or deflection from placing and tamping the concrete.

Form material shall be clean at the time it is used and shall be given a coating of light oil, or other equally suitable material, immediately prior to the placing of the concrete.

All forms except back planks of curb shall be set with the upper edges flush with the specified grade of the finished surface of the improvement to be constructed, and all forms shall be not less than a depth equivalent to the full specified thickness of the concrete to be placed.

Back forms shall be held securely in place by means of stakes driven in pairs at intervals not to exceed 4 feet, one at the front form and one at the back. Clamps, spreaders, and braces shall be used to such extent as may be necessary to ensure proper form rigidity. Forms for walk, gutter, and similar work shall be firmly secured by means of stakes driven flush with the upper edge of the form at intervals not to exceed 5 feet. Form stakes shall be of sufficient size and be driven so as to adequately resist lateral displacement.

Commercial form clamps for the curb and gutter may be used provided they fulfill the requirements specified herein.

303-5.2.2 Slip-Forms. At the option of the Contractor and with the approval of the Engineer, slip-form equipment may be used for the construction of concrete curb and gutter.

Slip-form equipment shall be provided with traveling side and top forms of suitable dimensions, shapes, and strength to support the concrete for a sufficient length of time during placement to produce curb and gutter of the required cross section. The equipment shall spread, consolidate, and screed the freshly placed concrete to provide a dense and homogeneous product.

The slip-form equipment shall have automatic sensor controls which operate from an offset control line. The line and grade of the slip-form equipment shall be automatically controlled.

303-5.3 Placing Concrete. Concrete shall be placed on a subgrade sufficiently dampened to ensure that no moisture will be absorbed from the fresh concrete.

Concrete shall be placed in curb, gutter, and curb and gutter forms in horizontal layers not exceeding 6 inches in thickness, each layer being spaded along the forms and thoroughly tamped. Concrete may be placed in layers of more than 6 inches in thickness only when authorized by the Engineer and the spading and tamping is sufficient to consolidate the concrete for its entire depth.

After the concrete for walk has been placed, a strike-off shall be used to bring the surface to the proper elevation when compacted. It shall be spaded along the form faces and tamped to assure a dense and compact mass, and to force the larger aggregate down while bringing to the surface not less than 3/8 inch of the free mortar for finishing purposes.

Concrete shall be placed in cross gutters in horizontal layers of not more than 4 inches in thickness, each layer being spaded along the form faces and thoroughly tamped into a dense and compact mass. If internal vibrators are used, the full specified thickness may be placed in one operation.

After the concrete has been placed and tamped, the upper surface shall be struck off to the specified grade.

303-5.4.1 General. Joints in concrete curb, gutter, and walk shall be designated as expansion joints and weakened plane joints.

303-5.4.2 Expansion Joints. Expansion joints shall be constructed in curb, walk, and gutter as shown on the Plans or as specified herein. Such joints shall be filled with premolded joint filler conforming with the requirements prescribed in 201-3.2. No such joints shall be constructed in cross gutters, alley intersections, access ramps, or driveways except as may be approved by the Engineer.

One-quarter-inch joints shall be constructed in curb and gutter at the end of all returns except where cross gutter transitions extend beyond the curb return, in which case they shall be placed at the ends of the cross gutter transition. No joints shall be constructed in returns. Where monolithic curb and gutter is constructed adjacent to concrete pavement, no expansion joints will be required except at the EC and BC of curb returns.

Expansion joint filler 1/4 inch thick shall be placed in walk at the EC and BC of all walk returns and around all utility poles which may project into the concrete along the line of the work. One-quarter-inch joints shall be constructed in walk returns between the walk and the back of curb returns when required by the Engineer. At the EC and BC and around utility poles, the joint filler-strips shall extend the full depth of the concrete being placed. Joint filler-strips between walk and curb shall be the depth of the walk plus 1 inch with the top set flush with the specified grade of the top of curb.

All expansion joint filler strips shall be installed vertically, and shall extend to the full depth and width of the work in which they are installed, and be constructed perpendicular to straight curb or radially to the line of the curb constructed on a curve. Expansion joint filler materials shall completely fill these joints to within 1/4 inch of any surface of the concrete. Excess filler material shall be trimmed off to the specified dimension in a neat and workmanlike manner. During the placing and tamping of the concrete, the filler strips shall be held rigidly and securely in proper position.

303-5.5.1 General. Finishing shall be completed as specified herein for the type work being performed.

303-5.5.2 Curb. The front forms may be stripped as soon as the concrete has set sufficiently. Class "B" mortar, as prescribed in 201-5.1 and thinned to the consistency of grout, shall be immediately applied to the top and face of the curb. If monolithic curb and gutter is being constructed, this mortar shall be applied to the full exposed curb face; otherwise, it shall extend 2 inches below the gutter surface.

The face and top of the curb shall then be carefully troweled to a smooth and even finish; the top being finished to a transverse slope of 1/4 inch toward the gutter, with both edges rounded to a radius of 1/2 inch. The troweled surface shall be finished with a fine-hair broom applied parallel with the line of the work. The edge of the concrete at all expansion joints shall be rounded to a 1/4 inch radius. The surface of the work shall be finished as prescribed; after which the name of the Contractor, together with the year in which the improvement is constructed, shall be stamped therein to a depth of 1/4 inch in letters not less than 3/4 inch high, at the BC and EC of curb returns.

Joints shall conform to 303-5.4.

303-5.5.3 Walk. The forms shall be set to place the finished surface in a plane sloping up from the top of curb 2 percent when measured at right angles to the curb.

Following placing, the concrete shall be screeded to the required grade, tamped to consolidate the concrete and to bring a thin layer of mortar to the surface, and floated to a smooth, flat, uniform surface. The concrete shall then be edged at all headers, given a preliminary troweling and provided with weakened plane joints.

Walk shall be steel troweled to a smooth and even finish. All formed edges shall be rounded to a radius of 1/2 inch. Edges at expansion joints shall be rounded to a radius of 1/8 inch. Preliminary troweling may be done with a longhandled trowel or "Fresno", but the finish troweling, shall be done with a hand trowel. After final troweling, walk on grades of less than 6 percent shall be given a fine-hair-broom finish applied transversely to the centerline. On grades exceeding 6 percent, walk shall be finished by hand with a wood float. Walk shall be remarked as necessary after final finish, to assure neat uniform edges, joints, and score lines.

Scoring lines, where required, shall have a minimum depth of 1/4 inch and a radius of 1/8 inch. When longitudinal scoring lines are required, they shall be parallel to, or concentric with, the lines of the work. Walk 20 feet or more in width shall have a longitudinal center scoring line. In walk returns, one scoring line shall be made radially midway between the BCR and ECR. When directed by the Engineer, longitudinal and transverse scoring lines shall match the adjacent walk. The Contractor shall have sufficient metal bars, straightedges, and joint tools on the project.

Headers shall remain in place for at least 16 hours after completion of the walk but must be removed before the Work is accepted.

303-5.5.4 Gutter. After the concrete has been thoroughly tamped to force the larger aggregate into the concrete and bring to the top sufficient free mortar for finishing, the surface shall be worked to a true and even grade by means of a float, troweled with a longhandled trowel or "Fresno", and wood-float finished. The flowline of the gutter shall be troweled smooth for a width of approximately 4 inches for integral curb and gutter and 4 inches on either side of the flowline on cross gutters and longitudinal gutters. The outer edges of the gutter shall be rounded to a radius of 1/2 inch.

Side forms shall remain in place for at least 24 hours after completion of the gutter, but must be removed before the work will be accepted.

Joints shall conform to 303-5.4.

303-5.5.5 Alley Intersections, Access Ramps, and Driveways. Alley intersections, access ramps, and drive-ways shall be constructed as specified for concrete pavement in 302-6, except final finishing for alley intersections, access ramps, and the sloping portion of driveways shall be done by hand with a wood float and the remaining portion of the driveway finished as specified for walks in accordance with 303-5.5.3.

303-5.6 Curing. Immediately after finishing operations are completed, curing compound conforming to 201-4.1 shall be applied.

The curing compound shall be applied in a manner to entirely cover all exposed surfaces of the concrete with a continuous membrane.

No power equipment used for the preparation of sub-grade will be permitted adjacent to concrete curb, gutter, or alley intersections until the fourth day following placement of the concrete. The placement of bituminous pavement adjacent to concrete curb, gutter, or alley intersections will not be permitted until the seventh day following the placement of concrete nor will concrete paving operations be permitted until the seventh day where placing or finishing equipment will ride on the previously placed concrete. If admixtures, additional cement or Type III cement is used to obtain high early strength concrete in accordance with 201-1, grading operations will be permitted on the second day following the placement of the concrete and paving operations on the third day.

303-5.7 Repairs and Replacements. Any new work found to be defective or damaged prior to its acceptance shall be repaired or replaced as approved by the Engineer.

303-5.8 Backfilling and Cleanup. Backfilling to the finished surface of the newly constructed improvement must be completed before acceptance of the Work.

Upon completion of the work the surface of the concrete shall be thoroughly cleaned and the site left in a neat and orderly condition.

303-5.9 Measurement and Payment. Payment for concrete curbs, walks, gutters, cross gutters, alley intersections, access ramps, and driveways will be made as shown in the Bid.

303-6.1 General. Stamped concrete shall be natural or colored and imprinted with special tools to provide the pattern specified.

The Contractor shall install a sample for each color and pattern included in the Work. The sample shall be a minimum of 10 square feet which shall be inspected and approved by the Engineer. All other areas shall be installed to match the color and texture of the approved area. All coloring and curing compounds used in the Work shall be from the same manufacturer.

303-6.2 Concrete Placement. Placing of concrete shall conform to 302-6 and 303-5. The minimum slab thickness shall be 4 inches. The maximum size aggregate in the top 2 inches shall be 3/8 inch.

303-6.3 Color Applications. Required color shall be applied by Method A or B:

303-6.3.1 Method A (Dry Shake). Color hardener shall be applied evenly to the plastic surface by a dry shake method using approved manufacturer’s printed instructions. It shall be applied in two applications, wood-floated after each, and troweled only after the final floating.

303-6.4 Pattern. The pattern of stamped concrete shall be implanted, indented, imprinted or stamped into the surface by means of forms, molds, or other approved devices. The impressions shall be approximately 3/8 inch in width, not to exceed 112 inch in depth and be ungrouted unless otherwise specified. Expansion joints and control joints shall be located so as not to disrupt the pattern. Joints shall conform to 303-5.4.

303-6.5 Curing. Colored concrete shall be cured with a liquid curing compound in matching color complying with the requirement of ASTM C 309. The curing compound shall be applied in accordance with the approved manufacturer’s printed instructions. Curing with other clear, white-pigmented, or fugitive-dye curing compounds, or with plastic or other waterproof membrane will not be allowed.