SECTION STRUCTURAL PRECAST HOLLOW CORE SLABS

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Jeremy Hodge
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1 PART 1 GENERAL 1.01 SCOPE OF WORK A. The Contractor shall furnish all labor, materials, equipment and incidentals to provide a complete structural precast hollow core slab system as shown on the Contract Drawings and as herein specified. B. Coordinate with other trades for hanger requirements. Install hanger tabs in grout joints where requested RELATED WORK A. Section 03210, Concrete Reinforcement B. Section 03300, Cast-In-Place concrete 1.03 REFERENCED STANDARDS A. ACI Structural Concrete for Buildings. B. ACI Building Code Requirements for Reinforced Concrete. C. ACI 350 Code Requirements for Environmental Engineering Concrete Structures D. ANSI/AWS D1.1 - Structural Welding Code - Steel. E. ANSI/AWS D1.4 - Structural Welding Code - Reinforcing Steel. F. ASTM A36 - Structural Steel. G. ASTM A416 - Undercoat Seven-Wire Stress-Relieved Strand for Prestressed Concrete. H. ASTM A615 - Deformed and Plain Billet-Steel Bars for Concrete Reinforcement. I. ASTM C150 - Portland Cement. J. PCI MNL Manual for Quality Control for Plants and Production of Precast and Prestressed Concrete Products. K. PCI MNL Design Handbook - Precast and Prestressed Concrete. L. PCI MNL Manual on Design of Connections for Precast Prestressed Concrete. M. PCI MNL PCI Design for Fire Resistance of Precast Prestressed Concrete. TALL OAKS STP

2 N. PCI Manual for the Design of Hollow Core Slabs. O. UL - Underwriters' Laboratories. P. New York State Building Code 1.04 SUBMITTALS A. The Contractor shall submit Shop Drawings of proposed materials in accordance with Section and as herein specified. B. Product Data: 1. Submit manufacturer s specifications and instructions for manufactured materials and products. Include manufacturers certifications and PCI Quality Control Program test reports as required. C. Samples: 1. Submit samples representative of finished exposed face showing typical range of color and texture prior to commencement of production. 2. Sample Size shall be approximately 12 in x 12 in. and of appropriate thickness, representative of the proposed finished product. D. Shop Drawings 1. Submit shop drawings showing complete information for fabrication and installation of precast concrete units. Indicate member dimensions and crosssection, location size and any type of reinforcement, including special reinforcement and lifting devices necessary for handling and erection. 2. Submit erection drawings meet the requirements as outlined below a. Member piece marks and completely dimensioned size and shape of each member. b. Plans and/or elevations locating and defining all products furnished by the manufacturer. c. Section and details showing connections, cast-in items and their relation to the structure. d. Relation to adjacent materials. e. Joints and openings between members and between members and the structure. f. Description of all loose, cast-in and field hardware. TALL OAKS STP

3 g. Location, dimensional tolerances and details of anchorage devices that are embedded in or attached to the structure or other construction. h. Erection sequences i. All dead, live and other applicable loads used in the design. E. Submit structural design calculations performed by a registered engineer licensed in the State of New York experienced in the design of structural precast hollow core slabs. F. Design Modifications: 1. Submit design modifications necessary to meet performance requirement and field coordination. G. Test Reports: 1. Submit test reports on materials, compressive strength tests on concrete and water absorption tests on units. Two copies of the results shall be sent to the engineer prior to shipping materials to the jobsite. H. The precast concrete unit manufacturer and the erector shall submit the names and contact person of at least ten (10) past jobs performed supplying/installing units similar to the type required for this project QUALITY ASSURANCE A. The precast concrete manufacturing plant shall be certified by the Precast Concrete Institute (PCI), Plant Certification Program prior to the start of production. B. Perform work in accordance with the requirements of PCI MNL-116, PCI MNL-120 and PCI MNL-123. C. Fabrications Qualifications: 1. Firms which have ten (10) years of successful experience in fabrication of precast concrete units similar to the units required for this project will be acceptable. Fabricator must have sufficient in-door production capacity to produce the required units without causing a delay in work. 2. Slabs shall be prestressed, hollow core, machine cast in an enclosed factory with closely controlled mixing, casting and curing conditions. D. Erection Qualifications: 1. Regularly engaged for at least five (5) years in the erection of precast structural concrete similar to the requirements of this project. TALL OAKS STP

4 E. Welder qualifications shall be in accordance with AWS D1.1. F. Testing: 1. Compliance with the applicable provisions in MNL-116, Manual for Quality Control for Plants and Production of Precast and Prestressed Concrete Panels. G. Requirements of the regulatory agencies: 1. All codes, plus the following specifications, standards and codes are a part of these specifications. a. ACI 318 Building Code Requirements for Reinforced Concrete. b. AWS d1.1 Structural Welding Code Steel c. AWS D1.4 Structural Welding Code Reinforcing Steel d. All applicable ASTM specifications. e. Precast Concrete Institute, MNL-116, Manual for Quality Control for Plans and Production of Precast and Prestressed Concrete Products. f. New York State Building Code PRODUCT DELIVER, STORAGE AND HANDLING A. Product delivery, storage and handling shall be in accordance with Section and as herein specified. B. Delivery and Handling: 1. Deliver all precast concrete units to the project site in such quantities and at such times to ensure continuity of erection. 2. Handle and transport the units in a position consistent with their shape and design in order to avoid stresses which would cause cracking or damage. 3. Lift or support units only at the points shown on the shop drawings. 4. Place non-staining resilient spacers of even thickness between each unit. 5. Support units during shipment on non-staining shock-absorbing materials. 6. Don t not place units directly on the ground TALL OAKS STP

5 C. Storage at the jobsite: 1. Store and protect units to prevent contact with soil, staining and physical damage. 2. Store units, unless otherwise specified, with non-staining resilient supports located in the same position as when transported. 3. Store units on firm, level and smooth surfaces. 4. Place stored units so that identification marks are discernible, and so that production can be inspected. PART 2 - PRODUCTS 2.01 FABRICATORS A. The following suppliers shall be used to supply Hollow Core Plank for the project: 1. Oldcastle Building Systems Division, South Bethlehem, NY (518) Or approved equal. B. Substitutions: For suppliers who are not listed above must be approved by the Engineer. Supplier shall meet the following requirements: 1. Company specializing in the manufacturing the work of this Section with ten years documented experience and certified by the Prestressed Concrete Institute Plank Certification Program. 2. Products must meet or exceed all the requirements of this Section MATERIALS A. All materials used in the fabrication of the Hollow Core Plank shall meet the requirements of ACI 318, where applicable. B. Portland Cement meeting the requirements of ASTM C150, type I or II. Manufacturer to specify type of Portland cement to be used at time of shop drawing submittal. C. Admixtures: 1. Air-entraining admixtures shall meet the requirements of ASTM C Water reducing, retarding, accelerating, high range water reducing admixtures shall meet the requirements of ASTM C494. TALL OAKS STP

6 D. Water shall be potable or free from foreign material in amounts harmful to concrete and embedded steel. E. Tensioning Steel Tendons: ASTM A4169, Grade 270K, of sufficient strength commensurate with member design. F. Reinforcing Steel: ASTM A615, deformed steel bars. G. Wire: ASTM A82, Cold-drawn steel. H. Welding Studs: AWS D1.1 I. Grout: Non-shrink, non-metallic, minimum yield strength of 10,000 psi at 28 days. J. Bearing Strips: 1. Tempered hardboard. 2. Plastic: Mulit-monomer plastic strips shall be non-leaching and support construction loads with no visible overall expansion. K. Ceiling caulk: Latex type equivalent to Pecora AC20 or equal 2.03 CONCRETE MIXES A. Twenty-eight (28) day compressive strength shall be a minimum of 5,000 psi. B. Release strength shall be a minimum of 3,000 psi ACCESSORIES A. Connecting and Supporting Devices: ASTM A36 carbon steel plates, angles, items cast into concrete, or items connected to steel framing members, inserts, conforming to PCI MNL-123 unfinished. Do not paint surfaces in contact with concrete or surfaces requiring field welding. B. Core Hole End Plugs: Cardboard insert and concrete fill. C. Bearing Pads: High density plastic, 1/8 inch thick, smooth on both sides FABRICATION A. Manufacturing procedures shall be in general compliance with PCI MNL-116. B. Embed anchors, inserts, plates, angles, and other items at locations indicated on shop drawings of other trades. TALL OAKS STP

7 C. Provide required openings and embed accessories provided by other Sections, where indicated. Manufacturer shall plant cast rough openings with a minimum dimension of ten (10 ) inches manufacturing tolerances in any direction. Openings to be rectangular or square only. Certain headered opening sizes may require concrete fill by General Contractor, properly reinforced, to obtain required size. D. Patching: Will be acceptable providing the structural adequacy of the hollow core unit is not impaired. E. Clean reinforcement of loose rust and mill scale, earth and other materials which reduce or destroy bond with concrete. F. Accurately position, support and secure reinforcement against displacement by form work, construction or concrete placement operation. Locate and support reinforcing by metal chairs, runners, bolsters, spacers and hangers as required. G. Place reinforcement to obtain at least the minimum coverage for concrete protection. Arrange, space and securely tie bars and bar supports to hold reinforcement in position during concrete placement operations. Set wire ties so ends are directed into concrete, not towards exposed concrete surfaces. H. Pretensioning of tendons for prestressed concrete may be accomplished either by single stand tensioning method or multiple-strand tensioning method. Comply with PCI MNL-116 requirements. I. Cut exposed ends of stressing tendons. J. Weight of slabs shall not exceed 45 psf for 6, 57 psf for 8 or 82 psf for COMPONENTS A. Nominal thickness and plank widths to be as shown on Drawings FINISHING A. Plant Finish: Finish members to PCI MNL Standard - Finish A grade. B. Surface may contain small surface holes caused by air bubbles, minor chipping or spalling at edges or ends, without major discoloration FABRICATION TOLERANCES A. Conform to PCI MNL-116. as follows: 1. Maximum Variation from Nominal Dimensions: TALL OAKS STP

8 a. Length of precast units shall be + 1/2 inch of the length indicated on the approved shop drawing. b. Width of precast concrete units: + 1/4 inch. c. Thickness of precast concrete units: + 1/4 inch. d. Location of inserts within units: + 1 inch. e. Differential camber between adjacent units of the same design: + 1/4 inch per 10 ft., but not greater than 1/2 inch. f. Squareness of ends (vertical and horizontal alignment): + 1/4 inch TESTS A. Provide analysis and testing of stressing tendons under provisions of Section B. Cylinder test of concrete quality shall be made by manufacturer in accordance with ASTM C 192, for each mix design, for each day of production, or for each 50 cubic yards of concrete. PART 3 - EXECUTION 3.01 INSPECTION A. All bearing surfaces including lintels to be installed by others prior to slab erection. Where masonry walls are used as bearing surfaces, the top course shall be (filled) solid. B. Weld angles, anchor inserts in bearing surfaces, and supporting structures shall be installed plumb to line and grade by others prior to erection of slabs. Precast concrete slab contractor will verify that structure and anchorage inserts are within allowable tolerances C. No broken, cracked, spalled, warped, or otherwise defective units shall be erected, unless they are judged structurally adequate, and are capable of cosmetic repair with proper patching. D. Where masonry walls are used as bearing surfaces, the top course shall be solid filled U-block or other solid, smooth, level surface PREPARATION A. General contractor shall coordinate delivery and erection of precast concrete units, provide clear site, provide and maintain firm and level access roads to allow crane and trucks to reach work area under their own power. TALL OAKS STP

9 B. Care shall be taken to protect the work and material of other trades during installation of slabs INSTALLATION A. Precast concrete slabs shall be installed according to approved shop drawings and details by mechanics experienced in precast concrete slab erection. B. Units shall be erected tight and at right angles to bearing surfaces unless shown otherwise. Minimum bearing shall be 2-1/2 inches on steel, 3 inches on concrete and 3-1/2 inches on masonry. Align and level precast concrete slabs using shims, bolts, or jacks. C. Where weld inserts are shown, precast concrete slab contractor shall weld inserts in slabs to bearing surfaces. All field welding shall be done by certified welders using equipment and material compatible to the base material. D. Install hanger tabs in joints as required by other trades. E. Grouting Joints: 1. Clean joints before grouting. 2. Grout for joints shall be 1 part Portland cement, 3 parts sand, and water. 3. Fill longitudinal keyways between units with grout, this does not include grouting butt joints or joints between plank and other materials. 4. Remove grout that seeped through to ceiling below before grout hardens. 5. Grout plank joints; trowel smooth. 6. Transition dissimilar elevations of adjoining planks with grout to a maximum slope of 1:12. F. Openings greater than 10 inches square to be saw cut in field. Openings 10 inches or less will be done by trades requiring same. However, if more than two openings occur in any individual slab, approval of the precaster must be obtained prior to making any cuts. (A number of closely spaced small openings could effectively cut all prestressing strands and destroy the structural strength of the slab.) G. All openings required in the precast slabs shall be indicated on the structural plans TOLERANCES A. Erect members level and plumb, within allowable tolerances. B. Conform to PCI MNL-116 as follows: TALL OAKS STP

10 1. Erect to the following tolerances: a. Maximum Variation from Plane or Locations Indicated on Drawings: 1/4 inch/10 feet and 3/8 inch in 100 feet, noncumulative. b. Maximum Offset from True Alignment Between Members: 1/4 inch. c. Maximum Variation from Dimensions Indicated on Reviewed Shop Drawings: Plus or minus 1/8 inch. 2. Exposed Joint Dimension: 3/8 inch plus or minus 1/4 inch. 3. When members cannot be adjusted to conform to design or tolerance criteria, cease work and advise Architect/Engineer. Execute modifications as directed ADJUST AND CLEAN A. Planks that are broken, cracked, or chipped shall be repaired or replaced. B. After erection and grouting is completed the general contractor will be responsible for the protection of the slabs. C. Remove rubbish and debris resulting from precast concrete slab work from premises upon completion. Protect work of this section from fabrication to installation ERECTION A. Erect members without damage to structural capacity, shape, or finish. Replace or repair damaged members. B. Align and maintain uniform horizontal, end joints, as erection progresses. C. Maintain temporary bracing in place until final connection is made. Protect members from staining. D. Install bearing pads and sill seal at bearing ends of planks as indicated. E. Adjust differential camber between precast members to tolerance before final attachment. F. Secure units in place. Perform welding in accordance with ANSI/AWS D PROTECTION A. Protect members from damage caused by field welding or erection operations. TALL OAKS STP

11 B. Provide non-combustible shields during welding operations. C. The erector shall be responsible for any chipping, spalling, cracking or other damage to the units after delivery to the jobsite unless damage is caused in site storage by others. After installation is completed, an further damage shall be the responsibility of the general contractor CLEANING A. Clean weld marks, dirt, or blemishes from surface of exposed members. END OF SECTION TALL OAKS STP

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GUIDE SPECIFICATIONS For STRUCTURAL PRECAST HOLLOW CORE SLABS SECTION 03410

GUIDE SPECIFICATIONS For STRUCTURAL PRECAST HOLLOW CORE SLABS SECTION 03410 Note to user: These guide specifications are provided by Mid- States Concrete Products as a service to you; they are NOT specific