676CEMENT CONCRETE SIDEWALKS

676.1DESCRIPTION—This work is construction of cement concrete sidewalks, driveway aprons, and curb

ramps on an aggregate bed.

676.2MATERIAL—

• ClassS Cement Concrete. Section 704

• Aggregate. Section 350.2

• Reinforcement Steel. Section 709.3

• Premolded Expansion Joint Filler. Section 705.1

• Concrete Curing Compound. Section 711.2(a)

• Curing and Protecting Covers. Section 711.1

• Mortar. Section 1001.2(d)

• Joint Sealing Material. Section 705.4 (a), (b), or (c)

• Penetrating Sealer. Section 503.2

676.3CONSTRUCTION—As shown on the Standard Drawings and as follows:

in Section 203.1(a), and form the foundation at a depth 10 inches parallel with the finished surface of the sidewalk. If directed, remove unsuitable material as specified in Section 203.1(b). Thoroughly compact the foundation; finish to a firm, even surface; moisten if required.

compacted bed 6 inches deep. The area to be compacted is defined as the area directly under the finished concrete and 6 inches beyond each side of the finished concrete if right of way allows.

Place concrete 4 inches deep. Strike off, finish, and test, as specified in Sections 501.3(k) and (p), except the contractor may use manual placement operations and apply a light broom finish to the cement concrete surface. Form outside edges and joints with a 1/4-inch radius-edging tool. Form transverse dummy joints at 5-foot intervals, approximately 1/8 inch wide, and at least 1 inch deep. Maximum allowable slump is 5 inches. Do not use vibratory screeds when concrete target slump is over 3 inches.

sidewalk, opposite expansion joints in adjacent curb, between the sidewalk and curb, and between the sidewalk and rigid structures. Install dummy joint and eliminate premolded expansion joint material between depressed curb, curb ramp, and flares if placed monolithically.

mechanized wire brush. Do not place poured joint-sealing material if the air temperature is less than 40F, unless allowed. Use heating equipment of an indirect heating type constructed as a double boiler. Provide positive temperature control and mechanical agitation. Obtain the safe heating temperature and recommended pouring temperature from the manufacturer’s shipping container. Place the material within this temperature range, but as close as possible to the recommended pouring temperature. Maintain a safe heating temperature. Maintain a single material batch at the pouring temperature for no more than 4 hours. Heat the material only once. Fill the joint reservoir, created by the cleaning operation, with sealing material to a depth 1/8 inch below the top of sidewalk. Do not allow sealing material to spread over concrete surfaces.

wait until after the bleeding has completed and the bleed water has evaporated or has been removed, and after the initial setting of concrete. Adding water to make finishing easier or reworking of bleed water into fresh concrete surface is not allowed. Excessive finishing or troweling of the concrete surface using Fresno and power trowel is not allowed.

compound after finishing and texturing, and within 30 minutes of the dissipation of bleed water. Apply curing compound homogenously to produce a uniform, solid white opaque coverage on the horizontal and vertical surfaces of the sidewalk. Apply at or greater than the manufacturer's recommended application rate and according to the manufacturer's recommendations. After curing a minimum of 28 days , clean the concrete surface of curing compound and apply a penetrating sealer.

removal of forms, fill minor honeycombed areas with mortar. As directed, remove and replace defective major honeycombed areas.

sidewalk, using acceptable embankment material, as specified in Section 206.3(b)4. Repair or replace existing pavement, curb, and sidewalk damaged because of construction. Satisfactorily dispose of unsuitable and surplus materials.

as shown on the Standard Drawings except for the detectable warning surface located at the bottom of each ramp. Construct the detectable warning surface as specified in Section 695. Create a slip -resistant, textured surface for the full width and length of the curb ramp and side -flares excluding the detectable warning surface. Use a coarse, stiff -toothed broom to create a textured pattern worked perpendicular to the slopes of the curb ramp. Shape rounded edges instead of sharp angled edges while the concrete is still plastic for all slope changes of the curb ramp especially where the top of the curb ramp meets adjacent sidewalk surfaces. Embed detectable warning surface in fresh, plastic concrete at the proper location for the curb ramp before the plastic concrete has set. The contractor may place cement concrete for depressed curb monolithically with curb ramps, side flares, or both. Do not place cement concrete curb monolithically with other cement concrete sidewalk.

centers transversely and longitudinally conforming to ASTM A1064 Steel Wire and Welded Wire Reinforcement. Secure fabric reinforcement at half-depth of cement concrete.

676.4MEASUREMENT AND PAYMENT—

Protective coating is incidental.

Protective coating and subbase are incidental. Depressed curb and curb ramp are paid separately according to their unit of measurement. If depressed curb is placed monolithically with curb ramps, side -flairs, or both, the depressed curb will be measured and paid separately from the curb ramps and side flairs.