CONCRETE WALKS AND CURBS SECTION CONCRETE WALKS AND CURBS PART 1 - GENERAL

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1 CONCRETE WALKS AND CURBS RELATED DOCUMENTS: SECTION CONCRETE WALKS AND CURBS PART 1 - GENERAL A. Drawings and general provisions of Contract, including General and Supplementary Conditions and Division 1 Specification Sections, apply to this section. 1.2 SUMMARY: Extent of concrete walks and curbs is indicated on drawings and in provisions of this section. 1.3 RELATED WORK SPECIFIED ELSEWHERE: A. CONCRETE REINFORCING - Division 03 B. CAST-IN-PLACE CONCRETE - Division 03 C. EXCAVATING, FILLING AND GRADING - Division 31 D. ASPHALT CONCRETE PAVING - Division QUALITY ASSURANCE: A. Reference Standards: Latest edition of all standards, specifications and codes, referred to below, including all addenda, revisions and supplements thereto, govern work under this section: 1. Applicable reference standards listed in Division 03 - CAST-IN-PLACE CONCRETE, and Division 03 - CONCRETE REINFORCING. 2. American Society for Testing and Materials (ASTM): a. ASTM C-171, Sheet Materials for Curing Concrete. b. ASTM C-309, Liquid Membrane-Forming Compounds for Curing Concrete. c. ASTM D-1751, Preformed Expansion Joint Fillers for Concrete Paving and Structural Construction (Non-Extruding and Resilient Bituminous Types). 3. Concrete Reinforcing Steel Institute (CRSI): a. CRSI 63 - Recommended Practice for Placing Reinforcing Bars. B. Regulatory Agencies: Conform to applicable requirements of local, state and federal codes and regulations. C. Allowable Tolerances: 1. Flatwork: True to plane 1/8 inch in ten feet. 2. Vertical faces: Longitudinal axis, 1/4 inch in ten feet. 1.5 SUBMITTALS, TEST REPORTS AND CERTIFICATES: Conform to Div 03 - CAST- IN-PLACE CONCRETE and Div 03 - CONCRETE REINFORCING.

2 CONCRETE WALKS AND CURBS ENVIRONMENTAL REQUIREMENTS, PRODUCT DELIVERY, STORAGE AND HANDLING: Conform to Div 03 - CAST-IN-PLACE CONCRETE and Div 03 - CONCRETE REINFORCING. A. Do not place concrete during rain, sleet or snow. 1.7 PROTECTION: A. Protect completed concrete work from pedestrian or vehicular traffic for minimum of 7 days. B. Protect concrete from mechanical disturbances, water flow, loading, shock and vibration during curing period. 2.1 MATERIALS: PART 2 - PRODUCTS A. Conform to requirements of Div 03 - CAST-IN-PLACE CONCRETE for concrete and concrete components. B. Conform to requirements of Div 03 - CONCRETE REINFORCING for following materials: 1. Reinforcing steel. 2. Reinforcing wire mesh. C. Forms: Metal or wood, straight and free of distortion and defects, of size and strength to resist movement during concrete placement and retain horizontal and vertical alignment until removal. Coat forms with nonstaining, clear form-release agent causing no discoloration or disfigurement of concrete surface. Use flexible spring steel or laminated wood forms, for curved surfaces. D. Expansion Joint Fillers: ASTM D E. Curing Material: Liquid membrane, ASTM C-309, Type ID, Class B; except that water loss shall not exceed 0.04 grams per square CM in 72 hours. 2.2 MIXES: Conform to requirements of Div 03 - CAST-IN-PLACE CONCRETE, for concrete exposed to weather with 4000 psi minimum 28-day compressive strength. 3.1 INSPECTION: PART 3 - EXECUTION A. Verify that all subsurface work is completed. B. Verify that earthwork is completed to correct line and grade, and that subgrade is smooth, compacted, and free of frost and excess water. C. Verify that work to be built into concrete, and forms for openings and recesses to accommodate work of other trades, are at indicated location and grade. D. Do not proceed with installation until unsatisfactory conditions are corrected.

3 CONCRETE WALKS AND CURBS FORMWORK: A. Set forms to line and grade, rigidly braced and secured. B. Install sufficient quantity of forms to allow continuous progress of work, and to permit retention of forms in place for a minimum of 24 hours after concrete placement. C. Clean forms after each use. Coat with form release agent as often as required to produce separation from concrete. 3.3 SUBGRADE PREPARATION: Moisten subgrade thoroughly and uniformly; avoid any accumulation of standing water. A. Adjust elevation of valve boxes, curb boxes, hand holes and other access facilities for underground utilities to meet finished walk grade. 3.4 JOINTS: A. Expansion Joints: 1. Spacing: Maximum 30 ft. O.C. unless otherwise indicated. 2. Place expansion joint filler for full depth of joint, flush with top surface of concrete. 3. Place expansion joint filler in one piece length for full length of joint. If more than one piece is required, lace or clip joint filler sections together. B. Construction and Contraction Joints: 1. Spacing: Place construction or contraction joints midway between expansion joints in walks and straight curbs. Place contraction joints at intervals equivalent to 20% of radius of curve, minimum interval: 3 ft. 2. Construction joints: Place at end of pours and where placement operations are stopped for a period of 30 minutes or more, except where pours terminate at expansion joints. 3. Contraction joints: Form by tooling and edging or insertion of steel templates or division plates in plastic concrete; or, upon approval of Architect, saw cutting hardened concrete when surface will not be damaged by cutting. 3.5 REINFORCEMENT: A. Cleaning: Remove dirt, grease, oil, loose mill scale, excessive rust and foreign matter reducing bond with concrete. B. Placement: 1. Place and hold reinforcement in indicated position prior to placing concrete. Do not attempt to alter position of reinforcement after concrete placement. 2. Reinforcing bars: CRSI 63.

4 CONCRETE WALKS AND CURBS C. Splices: 3. Place wire fabric in mats of largest practical dimensions. 1. Tie lap splices securely with wire to prevent displacement during concrete placement. 2. Lap adjoining pieces one full mesh dimension minimum, offset end laps in adjacent mats to prevent continuous laps. 3.6 PLACING CONCRETE: Conform to requirements of Div 03 - CAST-IN-PLACE CONCRETE. 3.7 FINISHING CONCRETE: Conform to requirements of Div 03 - CAST-IN-PLACE CONCRETE, except as modified below: A. Curbs: B. Walks: 1. Edge top surface round front arris to required radius. 2. Magnesium float surface. 3. Re-edge. 4. Rub exposed vertical face after removal of forms. 1. Magnesium float surface. 2. Score walks, to minimum depth of 1/2 inch, in pattern indicated on drawings. 3. Tool slabs with 2" wide edger at slab edges, expansion and contraction joints and at all slab scoring. 4. Steel trowel surface. 5. Broom surface with fine broom for level areas, coarse broom for inclines. 6. Re-edge slabs. 3.8 CURING: A. Keep concrete moist by application of specified curing material immediately after completion of finishing. 1. Apply material in two coats, conforming to manufacturer's directions on rates and times of application for anti-spalling treatment. B. Maintain concrete between 50 and 90 degrees F. during curing period. C. Curing Period: Minimum of 7 days. 3.9 PATCHING: A. Patch to match material, color and texture of surrounding area. B. Replace defective work if patching is not acceptable to Architect.

5 CONCRETE WALKS AND CURBS CLEAN UP: A. Immediately remove spills and stains from paved and finished surface area. B. Remove excess materials, forms and debris from project site. C. Remove signs and barricades upon completion of curing period. END OF SECTION

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