Section 03432 ARCHITECTURAL PRECAST CONCRETE

Section 03432

_{ARCHITECTURAL PRECAST CONCRETE}

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Architectural precast concrete panels and cast precast copings. B. Related Sections include but are not necessarily limited to:

1. Division 01, Additional General Requirements

2. Section 03100, Concrete Formwork

3. Section 04510, Masonry Cleaning

4. Section 07900, Joint Sealants

5. Section 09905, Architectural Paint Finishes

1.2 QUALITY ASSURANCE

A. Referenced Standards:

1. American Concrete Institute (ACI):

318 Building Code Requirements for Structural Concrete and

Commentary

2. ASTM International (ASTM):

A36 Standard Specification for Carbon Structural Steel

A108 Standard Specification for Steel Bar, Carbon and Alloy, Cold- Finished

A123 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

A153 Standard Specification for Zinc Coating (Hot-Dip) on Iron and

Steel Hardware

A167 Standard Specification for Stainless and Heat-Resisting

Chromium-Nickel Steel Plate, Sheet, and Strip

A185 Standard Specification for Steel Welded Wire Reinforcement, Plain, for Concrete

A497 Standard Specification for Steel Welded Wire Reinforcement, Deformed, for Concrete

A615 Standard Specification for Deformed and Plain Carbon-Steel

Bars for Concrete Reinforcement

C33 Standard Specification for Concrete Aggregates

C39 Standard Test Method for Compressive Strength of Cylindrical

Concrete Specimens

C97 Standard Test Methods for Absorption and Bulk Specific Gravity of Dimension Stone

C150 Standard Specification for Portland Cement

C173 Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method

C231 Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

C494 Standard Specification for Chemical Admixtures for Concrete

3. American Welding Society (AWS):

A5.1 Specification for Carbon Steel Electrodes for Shielded Metal Arc

Welding

D1.1 Structural Welding Code - Steel

D1.4 Structural Welding Code - Reinforcing Steel

4. Precast/Prestressed Concrete Institute (PCI):

MNL 117 Manual for Quality Control for Plants and Production of

Architectural Precast Concrete Products

PCI Design Handbook - Precast and Prestressed Concrete

5. The Society for Protective Coatings (SSPC): SP 3 Power Tool Cleaning

6. Building code:

a. International Code Council (ICC):

California Building Code and associated standards, 2010 Edition including all amendments, referred to herein as Building Code.

B. Qualifications:

1. The precast concrete manufacturing plant shall be certified by the PCI Plant

Certification Program.

a. Plant shall have been certified within past year from bid date.

2. Precast manufacturers shall have not less than 10 years experience in the manufacture of architectural precast concrete products similar to units required.

3. Erector shall have not less than 10 years experience in erection of precast units similar to units required.

C. Certify welders and welding in compliance with AWS D1.1 and AWS D1.4.

1. Welders shall have been qualified within past year from date of bid.

1.3 DEFINITIONS

A. Installer or Applicator:

1. Installer or applicator is the person actually installing or applying the product in the field at the Project site.

2. Installer and applicator are synonymous. B. Hardware: As defined in ASTM A153.

C. Galvanizing: Hot-dip galvanizing per ASTM A123 or ASTM A153 with minimum coating of 2.0 OZ of zinc per square foot of metal (average of specimens) unless noted otherwise or dictated by standard.

1.4 SUBMITTALS

A. Shop Drawings:

1. Submittals shall be made in accordance with the General Requirements, Additional General Requirements and as specified herein.

2. Fabrication and/or layout drawings:

a. Elevation view of each member, arrangement of units, details of special design or shapes, location and size of all reinforcing, lifting and erection embedments (both temporary and permanent), estimated cambers, methods of storage and handling, connection locations, loads being applied to the building structural frame.

1) Minimum plan scale: 1 = 96

_{2) Minimum detail scale: 1 = 8}

b. Method proposed for repairing damage to panels as result of erection.

3. Product technical data including:

a. Acknowledgement that products submitted meet requirements of standards referenced.

b. Manufacturer's installation instructions.

c. Structural calculations for prefabricated panels showing that embedded connections can support all loading. See structural drawings for conceptual structural connections.

d. Concrete mix design proposed by fabricator.

4. Certifications:

a. Certification of fabricator qualifications.

b. Certification that fabricator's plant complies with PCI MNL 117 referenced. c. Welder and welding process certification.

d. Certification that all panel design, connection design and submitted connection loads have been prepared by a Professional Civil or Structural Engineer licensed in the State of California, where the Project is located.

e. Certification of erector qualifications.

5. Test reports:

a. Compressive strength, water absorption and air content test results. B. Samples:

1. Before fabrication:

a. Four (4) sets of three (3) 12 x 12 x 2 inches samples of precast concrete for each type of specified finish and color showing color and texture range to be expected for ENGINEER's review.

b. Label samples to indicate name of Project, fabricator, type, color and source of cement and aggregate.

c. Two (2) sets of samples will be returned to the precast manufacturer and two

(2) sets will be kept at the Project site for comparison to large sample.

2. Full-sized samples:

a. After acceptance of small samples, fabricate and deliver to site one (1) full- size sample of each style of precast unit.

b. After ENGINEER's review and acceptance, samples may be incorporated in the Work and serve as standard of comparison for other units.

PART 2 - PRODUCTS

2.1 MATERIALS

A. Cement: ASTM C150.

_{1. Color: Gray (Panel Type A, B, Cand D) and White (Coping Type E).}

B. Aggregates: ASTM C33.

1. Aggregate color and size:

Panel Type A: fine aggregate 95 percent crushed black granite sand 5 percent white silica sand; coarse aggregate 5/8 inch to 1/4 inch white limestone

Panel Type B: fine aggregate crushed black granite; coarse aggregate 9/32 inch to

_{1/8 inch black granite.}

Panel Type C: fine aggregate 95 percent crushed black granite sand and 5 percent white silica sand; coarse aggregate 5/8 inch to 1/4 inch white limestone

Panel Type D: standard concrete mix design aggregates. Coping Type E: fine aggregate white sand.

C. Admixtures: ASTM C494.

D. Split face block (veneer): C-90 integral color 8 inches x 16 inches x 1-1/2 inches with bff/tan color to match existing screen wall on site.

E. Masonry Mortar: cement-lime type S conforming to ASTM C-270. F. Stainless Steel: 18-8, ASTM A167.

G. Welded Wire Reinforcement: ASTM A185 or ASTM A497, galvanized or cadmium plated.

_{H. Steel Plates and Shapes: ASTM A36.}

I. Reglets: As specified in Section 07600, Flashing and Sheet Metal.

_{J. Water: Potable.}

K. Sealants: See Section 07900, Joint Sealants.

_{L. Paint: See Section 09905, Architectural Paint Finishes.}

M. Welding Electrodes: E70 complying with AWS A5.1.

_{N. Headed Studs: Steel, ASTM A108.}

O. Deformed Bar Anchors: Steel, ASTM A615.

_{2.2 ACCESSORIES}

A. Provide all clip angles, bolts, washers, shims, nuts, and other accessories necessary for attachment of units to structure or other work.

2.3 FABRICATION

A. Fabricate all connection anchors, angles, plates, and other items secured to or embedded in precast necessary to support and anchor precast units.

1. Weld studs and anchors to steel using an automatic gun welding applicator, in accordance with manufacturer's instructions.

2. At external angles, provide panels having mitered joints with 3/4 inch quirk.

3. Provide lifting hooks or similar devices on large units to facilitate handling.

a. Lifting hooks or devices shall be located such that they will not harm the appearance of the unit in the finished position.

4. Vibrate concrete thoroughly during placement to eliminate all air pockets. B. Mark each unit for identification and date of casting.

C. Design Criteria:

1. Design units in compliance with ACI 318 and the latest edition of the PCI Design

Handbook - Precast and Prestressed Concrete.

a. Stripping release strength minimum 2500 pounds per inch.

b. Concrete compressive strength: Minimum 5,000 pounds per inch at 28 days. c. Concrete air content: 4 to 6 percent.

d. Concrete mix shall be designed by the precast manufacturer to best suit fabrication of units based on minimum compressive strength specified and finish specified.

1) Mix design shall be acceptable to the ENGINEER.

2. When accepted by ENGINEER, load tests may be substituted for calculations.

3. Design and provide internal reinforcing and embedded connections to withstand following:

a. Wind pressure: 30 psf positive and negative.

_{b. Dead load of panel plus all superimposed loads.}

c. Erection forces.

d. Temperature and shrinkage stresses. e. Earthquake lateral forces.

4. Reinforce units with welded wire reinforcement or reinforcing bars according to design criteria.

a. Provide following minimum reinforcing:

_{1) Panel thickness up to 4 inches: 4 x 4 - W4.5 x W4.5.}

2) Panel thickness over 4 inches: Two (2) layers 4 x 4 - W4.5 x W4.5.

D. When concrete cover on exterior face is less than 3/4 inch thick, provide galvanized reinforcing, otherwise, uncoated reinforcing permissible.

E. Embedded Steel: All inserts, anchors, and other embedded steel shall be galvanized steel per ASTM A167.

F. Headed Studs:

1. Minimum tensile strength of 60,000 pounds per inch.

2. Minimum yield strength of 52,000 pounds per inch. G. Deformed Bars Anchors:

1. Minimum tensile strength of 80,000 pounds per inch.

2. Minimum yield strength of 70,000 pounds per inch. H. Tolerances for Panels:

1. Fabricate so faces exposed to view after erection comply with following dimensional requirements:

a. Warpage: 1/16 inch/foot from nearest adjacent corner to maximum 1 inch. b. Bowing: (length of bow/360) to maximum of 3/4 inch.

c. Differential bowing between adjacent members: 1/4 inch.

_{d. Alignment of ribbed members:}

1) 3/16 inch up to 40 feet.

2) 1/4 inch in 40 feet or more. e. Overall height and width:

_{1) 10 feet or under: +1/8 inch.}

2) 10 to 20 feet: +1/8 inch, -3/16 inch.

_{3) 20 to 30 feet: +1/8 inch, -1/4 inch.}

4) Each additional 10 feet: +1/16 inch per 10-foot length.

_{f. Thickness: +1/4 inch, -1/8 inch.}

g. Rib thickness, rib to edge of flange, distance between ribs: +1/8 inch.

_{h. Angular deviation of plane of side mold: (1 in 100).}

i. Deviation from square:

1) In any length: (1 in 600).

_{2) Maximum: 1/4 inch.}

j. Blockouts and openings within one (1) unit: +1/4 inch. k. Haunches: +1/4 inch.

l. Haunch bearing surface deviation: +1/8 inch.

_{m. Difference in relative position of adjacent haunch bearing surface: +1/4 inch.}

n. Dimensions not listed above: In any length: (1 in 2000) to maximum 1/8 inch.

_{I. Forms:}

1. Cast units in heavy forms on casting beds of concrete or other suitable, rigid construction.

2. Provide forms adequately braced and free of dents, gouges, or other irregularities.

J. Finish:

_{1. Exposed surfaces of precast concrete:}

Panel Type A: uniform smooth texture, light sandblast (light gray color).

_{Panel Type B: retarded texture, with light exposure (black color).}

Panel Type C: 4 inches on center 1-1/2 inches deep fractured fin texture (form liner)

_{with a medium sandblasted texture.}

Panel Type D: Cast in split face block (matching existing texture and color of masonry wall at the Plant).

Panel Type E: Simulated fine limestone texture (Limestone color).

_{2.4 SOURCE QUALITY CONTROL}

A. Testing:

1. Employ and pay for an independent testing laboratory accepted by ENGINEER

to perform all tests.

2. Before production of units, make, cure, and test one (1) set of cylinders and cubes for each type of concrete required.

3. During production of units, make, cure, and test one (1) set of cylinders and cubes for each 50 CY of concrete.

4. Make set of three (3) standard 6- x 12-inch cylinders, and three (3) 2-inch cube specimens.

a. Cure cylinders and cubes in same manner as precast units they represent.

5. Test cylinders in accordance with ASTM C39; one (1) at seven (7) days and two

(2) at 28 days.

6. Test cubes in accordance with ASTM C97 for water absorption and ASTM C173 or ASTM C231 for air content.

7. Provide all test results to ENGINEER.

a. Test results to indicate units they represent. B. Inspect quality of units prior to shipment.

C. Should products delivered to site be rejected due to materials or workmanship, discontinue delivery until defects in materials or workmanship have been corrected and certified in writing to the ENGINEER.

PART 3 - EXECUTION

3.1 PREPARATION

A. Correct defects or conditions which may interfere with or prevent a satisfactory installation.

3.2 ERECTION

A. Erect units in accordance with erection schedules.

B. Make joint between units 1/2 inch except as otherwise indicated on Drawings. C. Secure units by welding and/or bolting.

1. Provide one (1) flat and one (1) lock washer with each bolt and nut.

2. Set units on shims where indicated or necessary for level, uniform bearing.

D. After panels have been erected and welded and/or bolted to building frame, prepare steel in accordance with SSPC SP 3 and apply one (1) coat of paint to exposed steel surfaces.

1. See Section 09905, Architectural Paint Finishes.

E. Caulk all precast work joints as specified in Section 07900, Joint Sealants, and as indicated on Drawings.

F. Erect units within the following tolerance limits:

1. Maximum equal to maximum specified for structural frame.

2. Clearances between precast and structural frame: 1-1/2 inches minimum.

_{3. Joints:}

_{a. Face width: Plus or minus 3/16 inch.}

b. Taper in any length: (1 in 500) to maximum 1/4 inch.

_{c. Step in face: 1/4 inch.}

d. Jog in alignment of edge: 1/4 inch.

3.3 FIELD QUALITY CONTROL

A. Repair all damage to units after erection in accordance with manufacturer's recommendations and to satisfaction of ENGINEER.

3.4 CLEANING

A. After completion of setting, repair and caulking, clean all precast work thoroughly by scrubbing with fiber brushes, detergent, and clean water.

1. Refer to Section 04510, Masonry Cleaning, for detergent cleaner. B. Start at top of building and proceed downward.

C. Leave precast units clean and free of traces of cleaning compound.