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PART 1 GENERAL:
1.01 APPLICABLE PUBLICATIONS: The publications listed below form a part of this specification to the extent reference. The publications are referred to in the text by the basic designation only.
A. American Concrete Institute (ACI) Publications:
1. 211.1-81 Standard practice for selecting proportions for concrete.
2. 214-77 (R83) Recommended practice for evaluation of strength test results of concrete.
3. 301-84 Specifications for structural concrete for buildings.
4. 304-73 Recommended practice for measuring, mixing, transporting, and placing concrete.
5. 305r-82 Hot weather concreting.
6. 306r-78 Cold weather concreting.
B. American Society for Testing Materials (ASTM) Publications:
1. A 36-81a Structural steel.
2. A 185-79 Welded steel wire fabric for concrete reinforcement.
3. A 283-81 Low and intermediate tensile strength carbon steel plates, shapes, and bars.
4. A 615-82 Deformed and plain billet-steel bars for concrete reinforcement.
5. C 31-84 Making and curing concrete test specimens in the field.
6. C 33-84 Concrete aggregates.
7. C 39-83b Compressive strength of cylindrical concrete specimens.
8. C 94 Concrete batch plant, mixer, mixing and measuring.
9. C 150-84 Portland cement.
C. Prestressed Concrete Institute (PCI) and
Architectural Precast Association (APA) Publications:
1. MNL 117-77 Manual for quality control for plants and production of Architectural Precast Concrete products.
2. 2nd edition Architectural Precast Concrete.
1.02 DESCRIPTION OF WORK:
A. Furnish And Install All Architectural Precast Concrete Units:
A. Shop drawings and descriptive data: Before manufacture of A.P.C. units, submit and
obtain approval for shop drawings and descriptive data including the following:
1. Layout, dimensions, cross sections, and edge details, location and type of reinforcement including reinforcement for safe handling.
2. Design calculations showing compliance with indicated loading conditions.
3. Setting drawings for A.P.C. units and anchors.
B. Manufacturer's Mix Design:
1. Submit a mix design for the Architectural Precast Concrete including a complete list of materials with brand names and sources.
2. Provide test reports indicating that mix has been tested to meet properties specified.
3. Obtain approval before proceeding with manufacture.
C. Catalog Data:
1. Architectural Precast Concrete producer's literature and company information.
2. Plant certification information.
3. Anchorage information.
4. Joint sealant information.
D. Samples: Samples to be submitted as follows:
1. Submit Architectural Precast Concrete samples to illustrate quality, color and finish.
2. Color and machine honed finish to match Seaboard Concrete Products Company.
3. Sample #_____/__________on file at the architect's office.
1.04 DELIVERY AND STORAGE:
A. Deliver Architectural Precast Concrete units on supports designed for the protection of these units, or packed and wrapped on pallets for job site storage.
PART 2 PRODUCTS
A. Manufacturer's Mix Design:
1. Concrete shall have a 28 day compressive strength of 5,000 PSI and a 4 to 6 percent of water absorption.
B. Concrete Mix Materials:
1. Provide aggregates, sand, mineral pigments, Admixtures and White Portland Cement to produce concrete with the specified properties and capable of obtaining the approved color and machine honed finish.
C. Backing Mix:
1. Back up mix not allowed, cast units solidly with one concrete mix.
1. Aggregates shall be natural white stone particles to match the machine honed finish sample on file.
1. White Portland Cement,
2. ASTM C 150-84,
3. Type I or II.
1. ASTM C 494.
2. Calcium chloride shall not be used.
D. Water: Potable
1. Reinforcement bars:
a. ACI 301.
b. Galvanized after fabrication.
2. Welded wire fabric:
a. ASTM A 185 OR ASTM A 497. Galvanized.
F. Threaded type concrete inserts:
1. ASTM A 47 OR ASTM A 27. Plated or Galvanized.
G. Weld plate anchors:
1. ASTM A 36 Steel. Shop painted.
H. Flashing reglets:
1. Galvanized sheet metal.
I. Clip angles:
1. ASTM A 36 Steel. Shop painted.
1. ASTM A 36 Steel. Galvanized.
2.03 UNIT FABRICATION:
A. Formwork and fabrication tolerances:
1. Provide metal, concrete, wood or rubber forms, designed and built to resist deformation.
2. Provide dimensional tolerances as follows:
a. Overall unit dimensions - plus/minus 1/8 inch.
b. Cross sectional dimension - plus/minus 3/16 inch.
c. Deviation from square - not to exceed 1/8 inch.
d. Anchor location - plus/minus 1 inch.
1. ACI 301. Properly place, locate, and secure reinforcing bars and welded wire mesh.
C. Concrete mixing and measurement:
1. ASTM C 94.
D. Concrete placement:
1. ACI 303 AND MNL 117-77.
2. Deposit concrete continuously into forms to prevent formation of planes of weakness in units.
3. Place concrete within a temperature range between 50 and 90 degrees Fahrenheit.
4. Consolidate concrete to prevent segregation and to produce a dense concrete, free of honey combs.
5. Units shall be made by the "wet pour" process.
6. The "dry tamp" method will not be accepted.
E. Identification markings:
1. Mark each unit to correlate with approved shop/setting drawings.
2. Do not locate markings on finished surfaces.
F. Exposed to view/finished surfaces:
1. Provide a smooth, machined honed finish on all finished faces.
2. (Note: Front face of parapet coping units shall be machine honed finish; top and back of parapet coping may have a smooth form finish.)
G. Concealed surfaces:
1. Provide a form or troweled surface.
1. Maintain units in a damp environment until concrete attains 60% of design strength.
1. Producer to be Seaboard Concrete Products Company or an approved equal fabricator.
2. Manufacturing facility is to be a "certified plant" under the Certification programs of the Architectural Precast Association (APA) or the Prestressed Concrete Institute (PCI).
PART 3 - EXECUTION
3.01 Installation: Install Architectural Precast Concrete units in accordance with approved shop drawings and descriptive data, and as specified below:
A. Building framing system:
1. Allow for adjustment to compensate for sagging in the structural steel members as the architectural precast concrete units are erected.
B. Placing units:
1. Provide temporary supports and bracing as required to maintain unit position and alignment during attachment to the building.
2. Properly weld/bolt all connections after units are positioned.
C. Erection tolerances:
1. Locate units to accommodate adjacent materials, proper joint width, and alignment with adjacent units.
2. Units dimensional tolerances are:
a. Joint width - +/- 3/16 inch.
b. Unit alignment- +/- 1/4 inch.
1. Joint sealants specified under section 07920: sealants.
1. Protect exposed surfaces from staining and construction damage.
2. Extra care shall be taken to avoid damage and staining from tar used in the roofing operation.
1. Thoroughly clean all Architectural Precast Concrete units after installation.
2. Use detergent, SUR-clean, and ample water, using a brush to scrub clean.
PART 4 - QUALITY CONTROL:
4.01 Product Quality:
A. Provide a quality control program as mandated under the Plant certification programs of either the APA or PCI.
B. Rejection: Units may be rejected for the following deficiencies:
1. Nonconformance to specified tolerances,
2. Damage incurred during construction,
3. Ragged or irregular edges,
4. Honeycombs/voids on finished surfaces,
5. Excessive variation in color or finish from approved sample, or unit to unit,
6. Form lines or irregular surfaces,
7. Visible repairs or cracks,
8. Surface crazing.