GUIDE SPECIFICATIONS For STRUCTURAL PRECAST HOLLOW CORE SLABS SECTION 03410

Size: px

Start display at page:

Download "GUIDE SPECIFICATIONS For STRUCTURAL PRECAST HOLLOW CORE SLABS SECTION 03410"

Franklin White
6 years ago
Views:

1 GUIDE SPECIFICATIONS For STRUCTURAL PRECAST HOLLOW CORE SLABS SECTION Note to user: These guide specifications are provided by Mid- States Concrete Products as a service to you; they are NOT specific to Mid-States Concrete Products. They are intended to help ensure that the hollow core portion of your project is as successful as possible. 1.0 GENERAL 1.01 DESCRIPTION A. Work included: These specifications cover manufacture, transportation and erection of precast, prestressed concrete hollow core slabs, including grouting of joints between adjacent slab units. 1. Related work specified elsewhere: 2. Cast-in place concrete: Section B. QUALITY ASSURANCE 1. The precast concrete manufacturing plant shall be certified by the Prestressed Concrete Institute, Plant Certification Program prior to bidding. 2. Fabricator qualifications: a. Firms which have ten (10) years successful experience in fabrication of precast concrete units similar to units required for this project will be acceptable. Fabricator must have sufficient in door production capacity to produce required units without causing delay in work. b. Slabs shall be prestressed, hollow core, machine cast in an enclosed factory with closely controlled mixing, casting and curing conditions. 3. Erector qualifications: a. Regularly engaged for at least five (5) years in the erection of precast structural concrete similar to the requirement of this project. 4. Welder qualifications: a. In accordance with AWS D Testing: a. In general, compliance with applicable provisions of Prestressed Concrete Institute MNL-116, Manual for Quality Control for Plants and Production of Precast and Prestressed Concrete Products. Structural Precast Concrete Hollow Core Slabs

2 6. Requirements of regulatory agencies: a. All local codes, plus the following specifications, standards and codes are a part of these specifications: 1) ACI 318-Building Code Requirements for Reinforced Concrete. 2) AWS D1.1-Structural Welding Code-Steel. 3) AWS D1.4-Structural Welding Code-Reinforcing Steel. 4) ASTM Specifications-As referred to in Part 2, PRODUCTS, of this specification. 5) Prestressed Concrete Institute MNL-116, Manual for Quality Control for Plants and Production of Precast and Prestressed Concrete Products. C. SUBMITTALS 1. Shop drawings: a. Submit shop drawings showing complete information for fabrication and installation of precast concrete units. Indicate member dimensions and cross-section, location, size and any type of reinforcement, including special reinforcement and lifting devices necessary for handling and erection. 1. Indicate layout, dimensions and identification of each precast unit corresponding to sequence and procedure of installation. Indicate welded connections by AWS standard symbols. Detail inserts, connections and joints, including accessories and construction at openings in precast units. 2. Provide location and details of anchorage devices that are to be embedded in other construction. 2. Product Design Criteria: 1. Loadings for design a. Initial handling and erection stresses. b. All dead and live loads as specified on the contract drawings. c. All other loads specified for hollow core slab units where applicable. 2. Design shall be in accordance with ACI 318 or applicable codes. 3. Test Report: 1. Reports of tests on concrete and other materials upon request. 2.0 PRODUCTS 2.01 MATERIALS A. Portland cement: ASTM C150-Type I or III B. Admixtures: 1. Air-entraining admixtures: ASTM C260 Structural Precast Concrete Hollow Core Slabs

3 2. Water reducing, retarding, accelerating, high range water reducing admixtures: ASTM C494 C. Aggregates: ASTM C33 D. Water: 1. Potable or free from foreign materials in amounts harmful to concrete and embedded steel. E. Reinforcing steel: 1. Bars: Deformed billet-steel ASTM A Wire: Cold-drawn steel: ASTM A82 F. Prestressing strand: 1. Uncoated, 7-wire strand: ASTM A416 (including supplement), Grade 250K or 270K G. Welding studs: AWS D1.1 H. Structural steel plates and shapes: ASTM A36 I. Cement grout: Portland cement, ASTM C150, Type I, and clean, natural sand, ASTM C404. Mix at ratio of 1.0 part cement to 3.0 parts sand, by volume, with water required for placement and hydration. J. Bearing strips: 1. Tempered hardboard 2. Plastic: Multi-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 2.02 CONCRETE MIXES A. Twenty-eight (28) day compressive strength: Minimum of 5000 PSI B. Release strength: Minimum of 3500 PSI C. Admixtures: 1. Use water-reducing admixtures in strict compliance with manufacturer s directions. Use amounts as recommended by admixture manufacturer for climate conditions prevailing at time of placing. Adjust quantities of admixture as required to maintain quality control. 2. Use of calcium chloride, chloride ions, or other salts are not permitted MANUFACTURE A. Manufacturing procedures shall be in general compliance with PCI MNL-116. B. Manufacturing tolerances shall comply with PCI MNL116 for structural hollow core products. C. Openings: Manufacturer shall provide for those openings 10 in or larger (rectangular or square only) as shown on the structural drawings. Other openings shall be located and field drilled or cut by the trade requiring them after the hollow core slab units have been erected. Openings and/or cutting of prestressing strand shall be approved by Architect/Engineer and manufacturer before drilling or cutting. 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. Structural Precast Concrete Hollow Core Slabs

4 E. Hollow core slabs length shall be furnished only in one (1) inch increments 3.0 EXECUTION 3.01 PRODUCT DELIVERY, STORAGE AND HANDLING A. Delivery and handling 1. Hollow core slab units shall be lifted and supported during manufacturing, stockpiling and erection operations only at the lifting or supporting point and with approved lifting devices. 2. Transportation, site handling and erection shall be performed with acceptable equipment and methods, and by qualified personnel. B. Storage: 1. Store all units off ground. 2. Place stored units so that identification marks are discernible. 3. Separate stacked members by battens across full width of each slab unit. 4. Stack so that lifting devices are accessible and undamaged ERECTION A. Site access: The General Contractor shall be responsible for providing suitable access to the building, proper drainage and firm level bearing for the hauling and erection equipment to operate under their own power. B. Preperation: 1. The general contractor shall be responsible for: a. Providing true, level bearing surfaces on all field placed bearing walls and other field placed supporting members. b. All pipes, stacks, conduits and other such items shall be stubbed off at a level lower than the bearing plane of the prestressed concrete products until after the latter are set. C. Installation: 1. Installation of hollow core slab units shall be performed by the manufacturer or a competent erector with a minimum of five (5) years successful experience in erection of hollow core floor and/or roof slabs. Members shall be lifted by means of suitable lifting devices at points provided by the manufacturer. Bearing strips shall be set, where required. Temporary shoring and bracing, if necessary, shall comply with manufacturer s recommendations. Grout keys shall be filled. D. Furnish and install grout fill at butt ends, ends and side of hollow core slabs for the depth of the slabs only, if shown on shop drawings. All necessary forming to be the responsibility of General Contractor where required. E. Alignment: 1. Members shall be properly aligned and leveled as required by the approved shop drawings. Variations between adjacent members shall be reasonable, leveled out by jacking, loading, or any other feasible method as recommended by the manufacturer. F. Ceiling Finishes: 1. The underside of hollow core slabs shall be manufactured with a finished surface in accordance with the Prestressed Concrete Structural Precast Concrete Hollow Core Slabs

5 Institute MNL-116, Manual for Quality Control for Plants and Production of Precast and Prestressed Concrete Products. The underside surfaces will be satisfactory for the application of a medium textured acoustical material. Any surface preparation that may be required for finishes other than medium or heavy texture will be by the trade installing the final finish FIELD WELDING A. Field welding is to be done by certified welders using equipment and materials compatible to the base material ATTACHMENTS A. Subject to approval of the Architect/Engineer, hollow core slab units may be drilled or shot provided no contact is made with the prestressing steel. Should spalling occur, it shall be repaired by the trade doing the drilling or the shooting. Structural Precast Concrete Hollow Core Slabs

SECTION STRUCTURAL PRECAST HOLLOW CORE SLABS

SECTION STRUCTURAL PRECAST HOLLOW CORE SLABS 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