8-29 Section 848
848-1 Description
Construct Portland cement concrete sidewalks, driveways and curb ramps in accordance with the contract.
848-2 Materials
Refer to Division 10. Item Section Curing Material s 1026 Joint Filler 1028 -1 Joint Sealers 1028 -2, 1028 -3 Portland Cement Concrete, Class B 1000 Detectable warning for curb ramps shall consist of raised truncated domes. Use material for detectable warning systems as shown herein. Material and coating specifications must be stated in the Manufacturers Type 3 Certification and all Detectable Warning systems must be on the NCDOT APL. Install detectable warnings created from one of the following materials: precast concrete blocks or bricks, clay paving bri ck, gray or ductile iron castings , mild steel, stainless steel, and engineered plastics, rubber or composite tile. Only one material type for detectable warning will be permitted per project, unless otherwise approved by the Engineer. Detectable Warnings shall consist of a base with integrated raised truncated domes , and when constructed of precast concrete they shall conform to the material requirements . Detectable Warnings shall consist of a base with integrated raised truncated domes, and may be compris ed of other materials including, but not limited to, clay paving brick, gray iron or ductile iron castings, mild steel, stainless steel, and engineered plastics, rubber or composite tile, which are applied directly to the curb ramps by incorporating into or attaching to the existing ramp floor . The material shall have an integral color throughout the thickness of the material. The detectable warning shal l include fasteners, anchors, or adhesives for attachment in the existing ramp and shall be furnished a s a system from the manufacturer . Prior to installation, the Contractor shall submit to the Engineer assembling instructions from the manufacturer for each type of system used. The system shall be furnished as a kit containing all consumable materials and consumable tools, required for the application. They shall be capable of being affixed to or anchored in the concrete curb ramp, including green concrete (concrete that has set but not appreciably hardened). The system shall be solvent free and contain no volatile organic compounds (VOC). The system shall be resistant to deterioration due to exposure to sunlight, water, salt or adverse weather conditions and impervious to degradation by motor fuels, lubricants and antifreeze. When steel or gray iron or ductile iron casting products are provided, only product s that meet the requirements of Suba rticle 106 -1(B) may be used . Submit to the Engineer a Type 6 Certification, catalog cuts and installation procedures at least 30 da ys prior to installation for all.
848-3 Construction Methods
Where it is necessary to remove a portion of existing sidewalks or driveways, saw a neat edge along the pavement to be retained approximately 2 inches deep with a concrete saw before breaking the adjacent pavement away. Construct concrete in accordance with Section 825 and give a sidewalk finish, except as otherwise provided herein.
8-30 Broom the concrete surface in a transverse direction to traffic. Make joint spacing no less
than 5 feet. Where existing sidewalks are being widened, line up new transverse joints with existing joints in the adjacent sidewalk. Seal expansion joints where sidewalk and curb ramps are placed adjacent to concret e curb and/or gutter. Do not seal grooved joints. Do not place backfill adjacent to the sidewalk, driveway or curb ramp until at least 3 curing days, as defined in Article 825- 9, have elapsed unless otherwise approved by the Engineer . Compact backfill to a degree comparable to the adjacent undisturbed material. Do not place vehicles on the completed work until 7 curing days, as defined in Article 825- 9, have elapsed. When high early strength concrete is used, vehicles will be permitted on the completed w ork after 3 curing days have elapsed. Install detectable warnings for proposed curb ramps in accordance with the contract . Prior to placing detectable warnings in existing concrete curb ramps, saw cut to the full depth of the concrete, for other materi al remove as necessary, and adjust the existing subgrade to the proper grade. Place all detectable warnings in accordance to manufacturer’s recommendations.
848-4 Measurement and Payment
__" Concrete Sidewalk will be measured and paid in square yards, measured along the surface of the completed and accepted work. Such price includes, but is not limited to , excavating and backfilling, sawing the existing sidewalk, furnishing and placing concrete, and c onstructing and sealing joints. __" Concrete Driveway will be measured and paid in square yards, measured along the surface of the co mpleted and accepted work. Such price includes, but is not limited to , excavating and backfilling, sawing the existing driveway, furnishing and placing concrete, and constructing and sealing joints. Concrete Curb Ramps will be measured and paid in units o f each. Such price includes, but is not limited to , excavating and backfilling, sawing the existing sidewalk or driveway, furnishing and placing concrete, curb and gutter, constructing and sealing joints and furnishing and installing truncated domes shown in the Roadway Standard Drawings . Retrofit Existing Concrete Curb Ramps with detectable warnings constructed of any type material will be paid as the actual number of retrofitted curb ramps, completed and accepted. Such price and payment will be full compensation for excavating and backfilling; sawing, repairing and replacing portions of the existing curb ramp within the pay limits for retrofit shown on the detail; pavement repairs; f urnishing and placing detectable warnings, construction joints and removing and disposing of portions of the existing curb ramp when required and for all materials, labor, equipment, tools and incidentals necessary to complete the work. Remove and Replace Concrete Curb Ramps will be measured and paid in units of each. Such price includes, but is not limited to, excavating, removing and backfilling, sawing the existing sidewalk or driveway and furnishing and installing truncated domes and constructing the new curb ramp . Removal and disposal of existing curb ramps will be incidental to the work performed. Payment will be made under: Pay Item Pay Unit __" Concrete Sidewalk Square Yard __" Concrete Driveway Square Yard Concrete Curb Ramps Each Retrofit Existing Concrete Curb Ramp s Each Remove and Replace Concrete Curb Ramps Each