034500.pdf

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SECTION 03 45 00

PRECAST ARCHITECTURAL CONCRETE

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section includes the performance criteria, materials, production, and erection of architectural precast concrete cladding units. The work performed under this section includes all labor, material, equipment, related services, and supervision required for the manufacture and erection of the architectural precast concrete work shown on the construction documents.

1.2 RELATED WORK

A. Section 01 45 29, TESTING LABORATORY SERVICES: Materials testing and inspection during construction.

B. Section 03 30 00, CAST-IN-PLACE CONCRETE: Concrete.

C. Section 03 41 33, PRECAST STRUCTURAL PRETENSIONED CONCRETE: Precast pre-stressed structural building elements.

D. Section 04 05 13, MASONRY MORTARING: Mortar.

E. Section 04 05 16, MASONRY GROUTING: Grout.

F. Section 04 20 00, UNIT MASONRY: Masonry Facing.

G. Section 04 72 00, CAST STONE MASONRY: Cast Stone Facing.

H. Section 07 21 13, THERMAL INSULATION: Insulation for Insulated Panels.

I. Section 07 92 00, JOINT SEALANTS: Sealants and Caulking.

1.3 QUALITY ASSURANCE

A. Fabricator Qualifications: A firm that complies with PCI MNL 117 and the following requirements and is experienced in producing units similar to those indicated for this Project and with a record of successful in-service performance:

1. Participates in PCI’s Plant Certification program at the time of bidding and is designated a PCI-certified plant for Group A, Category

A1- Architectural Cladding and Load Bearing Units. Submit PCI certification.

2. Fabricator must have a minimum of three (3) years’ experience in

Precast Architectural Concrete work comparable to that shown and specified in not less than three (3) projects of similar scope

B. Erector Qualifications:

1. A precast concrete erector Qualified by the Precast/Prestressed

Concrete Institute (PCI) prior to beginning work at the project site.

Submit a current Certificate of Compliance furnished by PCI designating

03 45 00 - 2 qualification in Category A (Architectural Systems) for non-load-bearing members. Submit qualifications.

C. Testing Laboratory Accreditation Requirements: Construction materials testing laboratories must be accredited by a laboratory accreditation authority. Submit a copy of the Certificate of Accreditation and Scope of

Accreditation.

D. Quality-Control Standard: For manufacturing procedures and testing requirements, quality-control recommendations, and dimensional tolerances for types of units required, comply with PCI MNL 117.

E. Preinstallation Conference: Conduct conference at Project site to comply with requirements in Division 01, GENERAL REQUIREMENTS. Coordinate with

COR to match existing building coloring and dimensions of brick, mortar, grout, and concrete.

1.4 PERFORMANCE REQUIREMENTS

A. Structural Performance: Provide units and connections capable of withstanding: the design criteria specified on the construction documents, self-weights and weights of materials supported or attached, for the conditions indicated.

1. Design Standards: Comply with ACI 318/ACI 318M and the design recommendations of PCI MNL 120 and PCI MNL 122 applicable to types of units indicated.

2. Limit deflection of precast members as follows:

a. Vertical live load – Span / 360.

b. Wind load – Height / 400.

B. Design concrete units and connections to maintain clearances at openings, to allow for fabrication and construction tolerances, to accommodate live load deflection, shrinkage and creep of primary building structure, and other building movements.

C. Thermal Movements: Provide for in-plane thermal movements resulting from annual ambient temperature changes of 120 degrees F.

D. Calculated Fire-Test-Response Characteristics: Where indicated, provide units whose fire resistance has been calculated according to PCI MNL 124.

1.5 SOURCE QUALITY CONTROL

A. Quality-Control Testing: Test and inspect precast concrete according to

Section 01 45 29, TESTING LABORATORY SERVICES and PCI MNL 117 requirements respectively. If using self-consolidating concrete also test and inspect according to PCI TR-6.

B. Testing: When determined by the COR that there is evidence that the concrete strength of precast concrete units may be deficient, employ an

03 45 00 - 3 independent testing agency at Contractor’s expense to obtain, prepare, and test cores drilled from hardened concrete to determine compressive strength according to PCI MNL 117:

1. Submit test results in writing on the same day that tests are performed, with copies to COR, Contractor, and precast concrete fabricator. Include the information required in Section 01 45 29, TESTING LABORATORY SERVICES and the following:

a. Identification mark and type of precast concrete units represented by core tests; design compressive strength; type of break;

compressive strength at breaks, corrected for length-diameter ratio;

and direction of applied load to core in relation to horizontal plane of concrete as placed.

C. Defective or Damaged Work: Units that do not comply with acceptability requirements, including concrete strength, manufacturing tolerances, and color and texture range are unacceptable. Chipped, spalled or cored units may be repaired, if repaired units match the visual mock-up. The COR will reject units that do not match the accepted samples and visual mock-up.

Remove unacceptable units from the site and replace with precast concrete units that comply with requirements.

1.6 SUBMITTALS

A. Product Data: For each type of product indicated.

B. Design Mixes: For each concrete mix along with compressive strength and water-absorption tests.

C. Shop (Erection) Drawings: Detail fabrication and installation of units.

1. Indicate member locations with distinctive marks that match marks placed on the panels. Provide plans, elevations, dimensions, corner details, shapes, cross sections and relationships to adjacent materials. Coordinate with COR to match existing building coloring and dimensions of brick, mortar, grout, and concrete.

2. Indicate aesthetic characteristics including joints, reveals, and extent and location of each surface finish.

3. Indicate separate face and backup mix locations, and thicknesses.

Indicate locations, extent and treatment of dry joints if two-stage casting is proposed.

4. Indicate welded connections by AWS standard symbols. Detail loose and cast-in hardware, and connections.

5. Indicate locations, tolerances and details of anchorage devices to be embedded in or attached to structure or other construction.

6. Indicate sequence of erection.

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7. Indicate locations and details of facing materials, anchors, and joint widths.

8. Design Modifications:

a. If design modifications are necessary to meet the performance requirements and field conditions, submit design calculations and drawings. Do not adversely affect the appearance, durability or strength of units when modifying details or materials and maintain the general design concept.

D. Samples: Design reference samples for initial verification of design intent representative of finishes, color, and textures of exposed surfaces of units.

E. Welding Certificates: Copies of certificates for welding procedure specifications (WPS) and personnel.

F. Qualification Data for fabricator, erector, and professional engineer:

List of completed projects with project names and addresses, names and addresses of COR and owners, and PCI Certification documentation.

G. Testing laboratory accreditations.

H. Material Test Reports: From an accredited testing agency indicating and interpreting test results of the following for compliance with requirements indicated:

1. Concrete strengths and mix designs.

I. Material Certificates: Signed by manufacturers certifying that each of the following items complies with requirements.

1. Cementitious materials.

2. Reinforcing materials and prestressing tendons.

3. Admixtures.

4. Bearing pads.

5. Structural-steel shapes and hollow structural sections.

6. Insulation

7. Facing units.

8. Anchors.

J. Description of stone anchor shear and tensile test assembly.

K. Certificate of Compliance.

L. Erectors Post Audit Declaration.

1.7 PRODUCT DELIVERY, STORAGE AND HANDLING

A. Comply with product handling requirements of PCI MNL 117 at the plant and project site.

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B. Deliver all units to the project site in such quantities and at such times to assure compliance with the agreed project schedule and proper setting sequence so as to limit unloading units temporarily on the ground.

C. Lift and support units only at designated points shown on the shop drawings.

D. Furnish loose connection hardware and anchorage items to be embedded in or attached to other construction without delaying the Work. Provide setting diagrams, templates, instructions, and directions, as required, for installation.

E. Store units with adequate dunnage and bracing, and protect units to prevent contact with soil to prevent staining, and to prevent cracking, distortion, warping, and other physical damage. Place stored units so identification marks are clearly visible for inspection.

1.8 WARRANTY

A. Construction Warranty: Comply with FAR clause 52.246-21 “Warranty of

Construction”.

1.9 APPLICABLE PUBLICATIONS

A. Publications listed below form a part of specification to extent referenced. Publications are referenced in text by basic designation only.

B. ASTM International (ASTM):

A27/A27M-20.............Standard Specification for Steel Castings, Carbon, for General Application

A36/A36M-19.............Standard Specification for Carbon Structural Steel

A47/A47M-99(2018)e1.....Standard Specification for Ferritic Malleable Iron

Castings

A108-18.................Standard Specification for Steel Bar, Carbon and

Alloy, Cold-Finished

A123/A123M-17...........Standard Specifications for Zinc (Hot-Dip

Galvanized) Coatings on Iron and Steel Products

A153/A153M-16a..........Standard Specifications for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

A184/A184M-19...........Standard Specification for Welded Deformed Steel

Bar mats for Concrete Reinforcement

A240/A240M-20...........Standard Specification for Chromium and Chromium-

Nickel Stainless Steel Plate, Sheet, and Strip for

Pressure Vessels and For General Applications

A276/A276M-17...........Standard Specification for Stainless Steel Bars and Shapes

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A283/A283M-18...........Standard Specification for Low and Intermediate

Tensile Strength Carbon Steel Plates

A307-14e1...............Standard Specifications for Carbon Steel Bolts, Studs, and Threaded Rod 60,000 PSI Tensile

Strength

A416/A416M-18...........Standard Specification for Low-relation, Seven-

Wire Steel Strand for Prestressed Concrete

A500/A500M-20...........Standard Specification for Cold-Formed Welded and

Seamless Carbon Steel Structural Tubing in Rounds and Shapes

A563-15.................Standard Specification for Carbon and Alloy Steel

Nuts

A563M-07(R2013).........Carbon and Alloy Steel Nuts (Metric)

A572/A572M-18...........Standard Specification for High-Strength Low-Alloy

Columbium-Vanadium Structural Steel

A615/A615M-20...........Standard Specification for Deformed and Plain

Carbon Steel Bars for Concrete Reinforcement

A666-15.................Standard Specification for Annealed or Cold-Worked

Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar

A675/A675M-14(2019).....Standard Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality, Mechanical

Properties

A706/A706M-16...........Standard Specification for Deformed and Plain Low-

Alloy Steel Bars for Concrete Reinforcement

A767/A767M-19...........Standard Specification for Zinc Coated

(Galvanized) Steel Bars for Concrete Reinforcement

A775/A775M-19...........Standard Specification for Epoxy Coated Steel

Reinforcing Bars

A780/A780M-20...........Standard Practice for Repair of Damaged and

Uncoated Areas of Hot-Dip Galvanized Coatings

A884/A884M-19...........Standard Specification for Epoxy-Coated Steel Wire and Welded Wire Fabric for Reinforcement

A934/A934M-19...........Standard Specification for Epoxy-Coated

Prefabricated Steel Reinforcing Bars

A1064/A1064M-18a........Standard Specification for Carbon-Steel Wire and

Welded Wire Reinforcement, Plain and Deformed, for

Concrete

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B633-19.................Standard Specification for Electrodeposited

Coatings of Zinc on Iron and Steel

C33/C33M-18.............Standard Specification for Concrete Aggregates

C40/C40M-20.............Standard Test Method for Organic Impurities in

Fine Aggregate for Concrete

C144-18.................Standard Specification for Aggregate for Masonry

Mortar

C150/C150M-20...........Standard Specification for Portland Cement

C260/C260M-10a(2016)....Standard Specification for Air Entraining

Admixtures for Concrete

C330/C330M-17a..........Standard Specification for Lightweight Aggregates for Structural Concrete

C373-18.................Standard Test Methods for Determination of Water

Absorption and Associated Properties by Vacuum method for Pressed Ceramic Tiles and Glass Tiles and Boil Method for Extruded Ceramic Tiles and

Non-tile Fired ceramic Whiteware Products

C494/C494M-19...........Standard Specification for Chemical Admixtures for

Concrete

C618-19.................Standard Specification for Coal Fly Ash and Raw or

Calcined Natural Pozzolan for Use in Concrete

C881/C881M-20...........Standard Specification for Epoxy Resin Base

Bonding Systems for Concrete

C920-18.................Standard Specification for Elastomeric Joint

Sealants

C979/C979M-16...........Standard Specification for Pigments for Integrally

Colored Concrete

C989/C989M-18a..........Standard Specification for Slag Cement for Use in

Concrete and Mortars.

C1017/C1017M-13e1.......Standard Specification for Chemical Admixtures for

Use in Producing Flowing Concrete

C1107/1107M-20..........Standard Specification for Packaged Dry, Hydraulic-Cement Grout (Non-shrink)

C1218/C1218M-20.........Standard Test Method for Water-Soluble Chloride in

Mortar and Concrete

C1240-20 ...............Standard Specification for Silica Fume Used in

Cementitious Mixtures

C1354/C1354M-15.........Standard Test Method for Strength of Individual

Stone Anchorages in Dimension Stone

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D412—16.................Standard Test Methods for Vulcanized Rubber and

Thermoplastic Elastomers – Tension

D2240-15e1..............Standard Test Method for Rubber Property—Durometer

Hardness

D4397-16................Standard Specification for Polyethylene Sheeting for Construction, Industrial, and Agricultural

Applications

E165/E165M-18...........Standard Practice for Liquid Penetrant Testing for

General Industry

E488/E488M-18...........Standard Test Methods for Strength of Anchors in

Concrete Elements

E709-15.................Standard Guide for Magnetic Particle Testing

F436/F436M-19...........Standard Specification for Hardened Steel Washers, Inch and Metric Dimensions

F593-17.................Standard Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs

F844-07a(R2013).........Standard Specification for Washers, Steel, Plain

(Flat), Unhardened for General Use

F3125/F3125M-19e1.......Standard Specification for High Strength

Structural Bolts, Steel and Alloy Steel, Heat

Treated, 120ksi (830MPa) and 150ksi (1040MPa)

Minimum Tensile Strength, Inch and Meter

Dimensions

C. American Concrete Institute (ACI):

211.1-91(R2009).........Standard Practice for Selecting Proportions for

Normal, Heavyweight, and Mass Concrete

211.2-98(R2004).........Standard Practice for Selecting Proportions for

Structural Lightweight Concrete

318/318R-19.............Building Code Requirements for Structural

Concrete and Commentary

D. American Association of State Highway and Transportation Officials

(AASHTO):

AASHTO LRFD-2017........LRFD Bridge Design Specifications, U.S., 8th

Edition

AASHTO M251-06..........Elastomeric Bearings

E. American Welding Society (AWS):

C5.4-93.................Recommended Practices for Stud Welding

D1.1/D1.1M-20...........Structural Welding Code - Steel

D1.4-18.................Structural Welding Code – Steel Reinforcing Bars

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F. American National Standards Institute (ANSI):

A108/A118/A136-19.......Installation of Ceramic Tile

A137.1-19...............Ceramic Tile

G. Precast/Prestressed Concrete Institute (PCI):

Architectural Precast Concrete – Color and Texture Selection Guide

MNL-117-13..............Quality Control for Plants and Production of

Architectural Precast Concrete Products

MNL-120-17..............Design Handbook – Precast and Prestressed Concrete

MNL-122-07..............Architectural Precast Concrete

MNL-124-11..............Design for Fire Resistance of Precast Prestressed

Concrete

MNL-127-99..............Erector’s Manual - Standards and Guidelines for the Erection of Precast Concrete Products

MNL-135-00..............Tolerance Manual for Precast and Prestressed

Concrete Construction

TR-6-15-E...............Guidelines For The Use of Self-Consolidating

Concrete In Precast/Prestressed Concrete

H. Military Specifications (MIL. Spec):

MIL-C882E-89............Cloth, Duck, Cotton or Cotton-Polyester Blend

Synthetic Rubber, Impregnated, and Laminated, Oil

Resistant

I. Department of Veterans Affairs:

Physical Security Design Manual for VA Mission Critical Protected

Facilities-January 2015

PART 2 - PRODUCTS

SPEC WRITER NOTE: Make material requirements agree with applicable requirements specified in the referenced Applicable Publications.

Update and specify only that which applies to the project.

2.1 MOLD MATERIALS

A. Molds: Rigid, dimensionally stable, nonabsorptive material, warp and buckle free, that will provide continuous and true precast concrete surfaces within fabrication tolerances indicated; non-reactive with concrete and suitable for producing required finishes:

1. Mold-Release Agent: Commercially produced form-release agent that will not bond with, stain or adversely affect precast concrete surfaces and will not impair subsequent surface or joint treatments of precast concrete.

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B. Form Liners: Units of face design, texture, arrangement, and configuration indicated. Provide solid backing and form supports to ensure that form liners remain in place during concrete placement. Use with manufacturer’s recommended liquid-release agent that will not bond with, stain, or adversely affect precast concrete surfaces and will not impair subsequent surface or joint treatments of precast concrete.

2.2 REINFORCING MATERIALS

A. Reinforcing Steel: ASTM A615/A615M, Grade 60 (Grade 420), deformed.

B. Weldable Reinforcing Bars: ASTM A706/A706M, deformed.

1. Galvanized Reinforcing Bars: ASTM A767/A767M, Class II zinc coated, hot-dip galvanized and chromate wash treated after fabrication and bending.

2. Epoxy-Coated Reinforcing Bars: ASTM A775/A775M or ASTM A934/A934M.

3. Steel Bar Mats: ASTM A184/A184M, assembled with clips.

a. Plain-Steel Welded Wire Reinforcement: ASTM A1064/A1064M, fabricated from galvanized and chromate wash treated steel wire into flat sheets.

b. Deformed-Steel Welded Wire Reinforcement: ASTM A1064/A1064M, flat sheet.

C. Epoxy-Coated-Steel Welded Wire Reinforcement: ASTM A884/A884M Class A coated, plain on flat sheet, Type 1 bendable coating.

D. Supports: Suspend reinforcement from back of mold or use bolsters, chairs, spacers, and other devices for spacing, supporting, and fastening reinforcing bars and welded wire reinforcement in place according to

PCI MNL 117.

2.3 CONCRETE MATERIALS

A. Portland Cement: ASTM C150/C150M, Type I or III.

1. For surfaces exposed to view in finished structure, use same type, brand, and mill source throughout the precast concrete production.

2. Standard gray Portland cement may be used for non-exposed backup concrete.

B. Supplementary Cementitious Materials for unexposed surfaces (backup concrete) only.

1. Fly Ash Admixture: ASTM C618, Class C or F with maximum loss on ignition of 3 percent.

2. Metakaolin Admixture: ASTM C618, Class N.

3. Silica Fume Admixture: ASTM C1240 with optional chemical and physical requirement.

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4. Ground Granulated Blast-Furnace Slag: ASTM C989/C989M, Grade 100 or

120.

C. Normal-Weight Aggregates: Except as modified by PCI MNL 117, ASTM C33/C33M, with coarse aggregates complying with Class 5S. Provide and stockpile fine and coarse aggregates for each type of exposed finish from a single source (pit or quarry) for entire project.

1. Face-Mix Coarse Aggregates: Selected, hard, and durable; free of material that reacts with cement or causes staining; to match selected finish sample.

a. Gradation: To match design reference sample.

b. Aggregate carefully graded from coarse to fine in proportions required to match approved samples.

c. Eliminate off color material from exposed aggregate.

2. Face-Mix Fine Aggregates: Selected, natural or manufactured sand of the same material as coarse aggregate, unless otherwise approved by COR.

a. Test sand for color value in accordance with ASTM C40/C40M. Sand producing darker than specified color standard is unacceptable.

D. Lightweight Coarse Aggregate: Except as modified by PCI MNL 117, ASTM C330/C330M, with absorption less than 11 percent and free from expanded clay.

E. Unexposed Surface (Backup) Concrete Aggregates: ASTM C33/C33M or

ASTM C330/C330M.

F. Admixtures: Admixtures containing calcium chloride, or more than 0.15 percent chloride ions or other salts by weight of admixture are not permitted.

1. Coloring Admixture: ASTM C979/C979M, synthetic or natural mineral-oxide pigments or colored water-reducing admixtures, temperature stable and non-fading.

2. Air Entraining Admixture: ASTM C260, certified by manufacturer to be compatible with other required admixtures.

3. Water-Reducing Admixture: ASTM C494/C494M, Type A.

4. Retarding Admixture: ASTM C494/C494M, Type B.

5. Water-Reducing and Retarding Admixture: ASTM C494/C494M, Type D.

6. High-Range, Water-Reducing Admixture: ASTM C494/C494M, Type F.

7. High-Range, Water-Reducing and Retarding Admixture: ASTM C494/C494M, Type G.

8. Plasticizing Admixture for Flowable Concrete: ASTM C1017/C1017M.

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G. Water: Potable; free from deleterious material that may affect color stability, setting, or strength of concrete and complying with chemical limits of PCI MNL 117.

2.4 STEEL CONNECTION MATERIALS

A. Carbon-Steel Shapes and Plates: ASTM A36/A36M except silicon (Si) content in the range of 0 to 0.03percent or 0.15 to 0.25 percent for materials to be galvanized. Steel with chemistry conforming to the formula Si + 2.5P <

0.09 is also acceptable.

B. Carbon-Steel Headed Studs: ASTM A108, Grades 1018 through 1020, cold finished and bearing the minimum mechanical properties for studs as indicated under PCI MNL 117, Table 3.2.3.

1. Make welds in accordance with AWS D1.1/D1.1M, Type A or B, with arc shields.

C. Carbon-Steel Plate: ASTM A283/A283M.

D. Malleable Iron Castings: ASTM A47/A47M. Grade 32510.

E. Carbon-Steel Castings: ASTM A27/A27M, Grade U-60-30 (Grade 415-205).

F. High-Strength, Low-Alloy Structural Steel: ASTM A572/A572M except silicon

(Si) content in the range of 0 to 0.03 or 0.15 to 0.25 percent for materials to be galvanized. Steel with chemistry conforming to the formula

Si + 2.5P < 0.09 is also acceptable.

G. Carbon-Steel Structural Tubing: ASTM A500/A500M, Grade B.

H. Wrought Carbon-Steel Bars: ASTM A675/A675M, Grade 65 (Grade 450).

I. Deformed-Steel Wire or Bar Anchors: ASTM A1064/A1064M or ASTM A706/A706M.

J. Carbon-Steel Bolts and Studs: ASTM A307, Grade A, carbon-steel, hex-head bolts and studs; carbon-steel nuts ASTM A563M (A563), Grade A; and flat, unhardened steel washers complying with ASTM F844.

K. High-Strength Bolts and Nuts: ASTM F3125/F3125M), Type 1, heavy hex steel structural bolts, heavy hex carbon-steel nuts, complying with

ASTM A563M (A563) and hardened carbon-steel washers complying with

ASTM F436M (F436).

2.5 STAINLESS-STEEL CONNECTION MATERIALS

A. Stainless-Steel Plate: ASTM A666, Type 304, of grade suitable for application.

B. Stainless-Steel Bolts and Studs: ASTM F593, alloy 304 or 316, hex-head bolts and studs; stainless-steel nuts; and flat, stainless steel washers.

Lubricate threaded parts of stainless steel bolts with an anti-seize thread lubricant during assembly.

C. Stainless-Steel Headed Studs: ASTM A276 and bearing the minimum mechanical properties for studs as indicated under PCI MNL 117, Table 3.2.3.

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2.6 BEARING PADS AND OTHER ACCESSORIES

A. Provide bearing pads for units as follows:

1. Elastomeric Pads: AASHTO M251, plain, vulcanized, 100 percent polychloroprene (neoprene) elastomer, molded to size or cut from a molded sheet, 50 to 70 Shore A durometer according to ASTM D2240, minimum tensile strength 15.5 MPa (2250 psi) per ASTM D412.

2. Random-Oriented, Fiber-Reinforced Elastomeric Pads: Preformed, randomly oriented synthetic fibers set in elastomer. Surface hardness of 70 to

90 Shore A durometer according to ASTM D2240. Capable of supporting a compressive stress of 20.7 MPa (3000 psi) with no cracking, splitting or delaminating in the internal portions of the pad. Test one specimen for each 200 pads used in the project. Submit test results.

3. Cotton-Duck-Fabric-Reinforced Elastomeric Pads: Preformed, horizontally layered cotton-duck fabric bonded to an elastomer. Surface hardness of

80 to 100 Shore A durometer according to ASTM D2240. Conforming to

Division II, Section 18.10.2 of AASHTO LRFD, or MIL-C-882E.

4. Frictionless Pads: Tetrafluoroethylene (teflon), glass-fiber reinforced, bonded to stainless or mild-steel plates, of type required for in-service stress.

5. High-Density Plastic: Multimonomer, nonleaching, plastic strip.

B. Reglets: Stainless steel, ASTM A240/A240M, Type 302 felt or fiber filled or cover face opening of slots.

C. Vents and Weeps: Polyvinyl chloride plastic tubing, (3/8 inch) inside diameter.

D. Provide sealant backings and sealant into stone-to-stone joints and stone-to-concrete joints in accordance with Section 07 92 00, JOINT

SEALANTS.

E. Accessories: Provide clips, hangers, plastic or steel shims, and other accessories required to install units.

2.7 GROUT MATERIALS

A. Sand-Cement Grout: Portland Cement, ASTM C150/C150M, Type I, and clean, natural sand, ASTM C144, or ASTM C404. Mix at ratio of 1 part cement to

2-1/2 parts sand, by volume, with minimum water required for placement and hydration.

B. Nonmetallic, Nonshrink Grout: Premixed, nonmetallic, noncorrosive, nonstaining grout containing selected silica sands, portland cement, shrinkage-compensating agents, plasticizing and water-reducing agents, complying with ASTM C1107/C1107M, Grade A for drypack and Grades B and C

03 45 00 - 14 for flowable grout and of a consistency suitable for application within a

30-minute working time.

C. Epoxy-resin grout: Two-component mineral-filled epoxy-resin: ASTM C881 of type, grade, and class to suit requirements.

2.8 CONCRETE MIXES

A. Prepare design mixes to match COR’s sample for each type of concrete required.

1. Limit use of metakaolin and silica fume to 10 percent of Portland cement by weight.

B. Provide design mixes prepared by a qualified independent testing agency or by qualified precast plant personnel at fabricator’s option.

C. Limit water-soluble chloride ions to the maximum percentage by weight of cement permitted by ACI 318/318M or PCI MNL 117 when tested in accordance with ASTM C1218/C1218M.

D. Normal Weight Concrete Face and Backup Mixtures: Proportion mixes by either laboratory trial batch or field test data methods according to

ACI 211.1, with materials to be used on Project, to provide normal-weight concrete with the following properties:

1. Compressive Strength (28 Days): 34.5 MPa (5000 psi).

2. Maximum Water-Cementitious Materials Ratio: 0.45.

3. Release strength as required by design.

E. Water Absorption: 6 percent by weight or 14 percent by volume, tested according to PCI MNL 117.

F. Add air-entraining admixture at manufacturer’s prescribed rate to result in concrete at point of placement having air content as follows.

G. Total air content for various sizes of coarse aggregate for normal weight concrete.

Total Air Content, Percent, by Volume

Nominal Maximum Size of Aggregate mm (inch)

Severe Exposure Moderate Exposure

Less than 9 (3/8) 9 7

9 (3/8) 7-1/2 6

13 (1/2) 7 5-1/2

19 (3/4) 6 5

25 (1) 6 5

38 (1-1/2) 5-1/2 4-1/2

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H. When included in design mixes, add other admixtures to concrete mixes according to manufacturer’s written instructions.

PART 3 - EXECUTION

3.1 MOLD FABRICATION

A. Molds: Construct and maintain molds, mortar tight, within fabrication tolerances and of sufficient strength to withstand pressures due to concrete-placement, vibration operations, and temperature changes and for prestressing and detensioning operations.

1. Form joints are not acceptable on faces exposed to view in the finished work.

2. Edge and Corner Treatment: Uniformly, chamfered, radiused to match existing.

3.2 THIN BRICK FACINGS

A. Place form liner templates accurately to provide grid for brick facings.

Provide solid backing and supports to maintain stability of liners while placing bricks and during concrete placement.

B. Match appearance of sample panel(s).

C. Securely place brick units face down into form liner pockets and place concrete backing mixture.

D. After stripping units, clean faces and joints of brick facing.

3.3 FABRICATION

A. Cast-in Anchors, Inserts, Plates, Angles, and Other Anchorage Hardware:

Fabricate anchorage hardware with sufficient anchorage and embedment to comply with design requirements. Position anchors for attachment of loose hardware and secure in place during precasting operations. Locate anchorage hardware where it does not affect position of main reinforcement or concrete placement.

1. Weld headed studs and deformed bar anchors used for anchorage according to AWS D1.1/D1.1M and AWS C5.4.

B. Furnish loose hardware items including steel plates, clip angles, seat angles, anchors, dowels, cramps, hangers, and other hardware shapes for securing units to supporting and adjacent construction.

C. Provide cast-in reglets, slots, holes, and other accessories in units as indicated on contract documents.

D. Provide cast-in openings larger than 254 mm (10 inches) in any dimension.

Do not drill or cut openings or reinforcing without approval of COR.

E. Reinforcement: Comply with recommendations in PCI MNL 117 for fabrication, placing, and supporting reinforcement.

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1. Place reinforcing steel and prestressing strand to maintain at least

19 mm (3/4 inch) minimum concrete cover. Increase cover requirements for reinforcing steel to 38 mm (1-1/2 inches) when units are exposed to corrosive environment or severe exposure conditions. Arrange, space, and securely tie bars and bar supports to hold reinforcement in position while placing concrete.

2. Install welded wire reinforcement in lengths as long as practicable.

Lap adjoining pieces at least one (1) full mesh spacing and wire tie laps, where required by design. Offset laps of adjoining widths to prevent continuous laps in either direction.

3. Clean reinforcement of loose rust and mill scale, earth, and other materials that reduce or destroy the bond with concrete. When damage to epoxy-coated reinforcing exceeds limits specified in ASTM A775/A775M, repair with patching material compatible with coating material and epoxy coat bar ends after cutting.

4. Accurately position, support, and secure reinforcement against displacement during concrete- placement and consolidation operations.

Completely conceal support devices to prevent exposure on finished surfaces.

F. Prestress tendons for units by pretensioning methods. Comply with

PCI MNL 117.

1. Protect strand ends and anchorages with paint to prevent corrosion and rust spots.

2. Delay detensioning or post-tensioning of precast, prestressed architectural precast concrete units until concrete has reached its indicated minimum design release compressive strength as established by test cylinders cured under the same conditions as concrete member.

3. Detension pretensioned tendons either by gradually releasing tensioning jacks or by heat-cutting tendons, using a sequence and pattern to prevent shock or unbalanced loading.

4. If concrete has been heat cured, detension while concrete is still warm and moist.

G. Mix concrete according to PCI MNL 117 and requirements in PART 2. After concrete batching, no additional water may be added.

1. At the fabricator’s option either of the following mix design/casting techniques may be used:

a. A single design mix throughout the entire thickness of panel.

b. Design mixes for facing and backup; using cement and aggregates for each type as indicated, for consecutive placement in the mold. Use

03 45 00 - 17 cement and aggregate specified for facing mix, use cement and aggregate for backup mix complying with criteria specified as selected by the fabricator.

H. Place concrete in a continuous operation. Comply with requirements in PCI

MNL 117.

I. Identify pickup points of units and orientation in structure with permanent markings, complying with markings indicated on shop drawings.

Imprint or permanently mark casting date on each unit on a surface that will not show in finished structure.

J. Cure concrete, according to requirements in PCI MNL 117, by moisture retention without heat accelerated heat curing using low-pressure live steam.

K. Repair damaged units to meet acceptability requirements of PCI MNL 117 and the COR.

L. Reinforce architectural precast concrete units to resist handling, transportation and erection stresses, and specified in-place loads, whichever governs.

M. Comply with requirements in PCI MNL 117 and requirements in this section for measuring, mixing, transporting, and placing concrete. After concrete batching, no additional water may be added.

N. Place face mixture to a minimum thickness after consolidation of the greater of 25 mm (1 inch) or 1.5 times the nominal maximum aggregate size, but not less than the minimum reinforcing cover of 38 mm (1-1/2 inches).

1. Use a single design mixture for those units in which more than one major face (edge) is exposed.

2. Where only one (1) face of unit is exposed, at the fabricator’s option, either of the following mixture design/casting techniques may be used:

a. A single design mix throughout the entire thickness of panel.

b. Separate mixtures for face and backup concrete; using cement and aggregates for each type as appropriate, for consecutive placement in the mold. Use cement and aggregate specified for face mixture.

Use cement and aggregate for backup mixture complying with specified criteria or as selected by the fabricator.

O. Thoroughly consolidate placed concrete by internal or external vibration without dislocating or damaging reinforcement and built-in items, and minimize pour lines, honeycombing, or entrapped air voids on surfaces. Use equipment and procedures complying with PCI MNL 117.

1. Place self-consolidating concrete without vibration in accordance with

PCI TR-6.

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P. Comply with PCI MNL 117 procedures for hot- and cold-weather concrete placement.

3.4 FABRICATION TOLERANCES

A. Fabricate units straight and true to size and shape with exposed edges and corners precise and true so each finished unit complies with PCI MNL 117 product tolerances as well as position tolerances for cast-in items.

1. Additional Position Tolerances: For cast-in items measured from datum line location, as indicated on shop drawings.

a. Location of Base Surface from End of Member: Plus or Minus 6 mm (1/4 inch).

B. Fabricate architectural trim units such as sills, lintels, coping, cornices, quoins, medallions, bollards, benches, planters, and pavers, with tolerances meeting PCI MNL 135.

C. Brick-Faced Architectural Precast Concrete Units.

1. Alignment of mortar joints:

a. Jog in Alignment: 3 mm (1/8 inch).

b. Alignment with Panel Centerline: Plus or Minus 3 mm (1/8 inch).

2. Variation in Width of Exposed Mortar Joints: Plus or Minus 6 mm

(1/4 inch).

3. Tipping of Individual Bricks from the Panel Plane of Exposed Brick

Surface: Plus 1.5 mm (1/16 inch); Minus 6 mm (1/4 inch) < depth of form liner joint.

4. Exposed Brick Surface Parallel to Primary Control Surface of Panel:

Plus 6 mm (1/4 inch); Minus 3 mm (1/8 inch).

5. Individual Brick Step in Face from Panel Plane of Exposed Brick

Surface: Plus 1.5 mm (1/16 inch); Minus 6 mm (1/4 inch) < depth of form liner joint.

D. Stone Veneer-Faced Architectural Precast Concrete Units:

1. Variation in Cross-Sectional Dimensions: For thickness of walls from dimensions indicated: Plus or minus 6 mm (1/4 inch).

2. Variation in Joint Width: 3 mm in 914 mm (1/8 inch in 36 inches) or a quarter of nominal joint width, whichever is less.

3. Variation is Plane between Adjacent Stone Units (Lipping): 1.6 mm

(1/16 inch) difference between planes of adjacent units.

3.5 FINISHES

A. Provide exposed panel faces free of joint marks, grain, and other obvious defects. Corners, including false joints to be uniform, straight and sharp. Finish exposed-face surfaces of units to match approved design with existing members as followed:

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1. PCI’s “Architectural Precast Concrete –Color and Texture Selection

Guide,” of plate numbers indicated.

2. As-Cast Surface Finish: Provide surfaces free of excessive air voids, sand streaks, and honeycombs.

3. Textured-Surface Finish: Impart by form liners to provide surfaces free of air voids, sand streaks, and honeycombs, with uniform color and texture.

4. Bushhammer Finish: Use power and hand tools to remove matrix and fracture coarse aggregates.

5. Exposed Aggregate Finish: Use chemical retarding agents applied to concrete forms and washing and brushing procedures to expose aggregate and surrounding matrix surfaces after form removal.

6. Abrasive-Blast Finish: Use abrasive grit, equipment, application techniques, and cleaning procedures to expose aggregate and surrounding matrix surfaces.

7. Acid-Etched Finish: Use acid and hot-water solution, equipment, application techniques, and cleaning procedures to expose aggregate and surrounding matrix surfaces. Protect hardware, connections and insulation from acid attack.

8. Honed Finish: Use continuous mechanical abrasion with fine grit, followed by filling and rubbing procedures.

9. Polished Finish: Use continuous mechanical abrasion with fine grit, followed by filling and rubbing procedures.

10. Sand-Embedment Finish: Use selected stones placed in a sand bed in bottom of mold, with sand removed after curing.

B. Finish exposed top and side surfaces of units to match face-surface finish.

C. Finish unexposed surfaces top and side of units by smooth steel-trowel finish.

D. Finish unexposed surfaces of units by float finish.

3.6 ERECTION PREPARATION

A. Deliver anchorage devices that are embedded in or attached to the building structural frame or foundation before start of such work. Furnish locations, setting diagrams, and templates for the proper installation of each anchorage device.

B. Examine supporting structural frame or foundation and conditions for compliance with requirements for installation tolerances, true and level bearing surfaces, and other conditions affecting performance. Proceed with installation only after unsatisfactory conditions have been corrected.

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C. Do not install units until supporting cast-in-place concrete building structural framing has attained minimum allowable design strength supporting steel or other structure is structurally ready to receive loads from precast.

3.7 ERECTION

A. Erect units level, plumb and square within the specified allowable tolerances. Provide temporary supports and bracing as required to maintain position, stability, and alignment of units until permanent connections are completed.

1. Install temporary steel or plastic spacing shims or bearing pads as precast concrete units are being erected. Tack weld steel shims to each other to prevent shims from separating.

2. Maintain horizontal and vertical joint alignment and uniform joint width as erection progresses.

3. Remove projecting lifting devices and use sand-cement grout to fill voids within recessed lifting devices flush with surface of adjacent precast concrete surfaces when recess is exposed.

4. Unless otherwise shown provide for uniform joint widths of 3/4 inch).

B. Connect units in position by bolting, welding, grouting, or as otherwise indicated on approved Erection Drawings. Remove temporary shims, wedges, and spacers as soon as practical after connecting or grouting are completed.

1. Disruption of roof flashing continuity by connections is not permitted;

concealment within roof insulation is acceptable.

2. Welding: Comply with and AWS D1.1/D1.1M and AWS D1.4/1.4M requirements for welding, welding electrodes, appearance of welds, and methods used in connecting welding work.

a. Protect units and bearing pads from damage by field welding or cutting operations and provide noncombustible shields as required.

b. When welds are not specified, provide continuous fillet welds, using not less than the minimum fillet as specified by AWS.

c. Clean weld affected metal surfaces and apply a minimum 2 mils

(0.002 inch) dry thickness coat of galvanized repair paint to galvanized surfaces in conformance with ASTM A780/A780M.

d. Visually inspect welds critical to precast connections. Visually check welds for completion and remove, reweld or repair defective welds.

3. At bolted connections, provide lock washers, tack welding, or other acceptable means to prevent loosening of nuts after final adjustment.

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a. Where slotted connections are used, verify bolt position and tightness. For sliding connections, properly secure bolt but allow bolt to move within connection slot. For friction connection apply specified bolt torque and check 25 percent of bolts at random by calibrated torque wrench.

4. Grouting Connections: Grout connections where required or indicated on shop (erection drawings). Retain flowable grout in place until strong enough to support itself. Pack spaces with stiff grout material, tamping until voids are completely filled. Place grout and finish smooth, level, and plumb with adjacent concrete surfaces. Promptly remove grout material from exposed surfaces before it affects finishes or hardens.

C. Attachments: Upon approval of COR, precast pre-stressed products may be drilled or "shot" for fasteners or small openings, provided reinforcing or pre-stressing steel is not damaged or cut.

1. Should spalling occur, repair according to this specification section.

D. Venting and Weeps: Where precast concrete panels form the outer wythe of cavity wall construction, vent the cavity wall.

1. Use polyvinyl chloride plastic tubing to vent the cavity.

2. Place plastic vent tubes "tilted down and out" in horizontal and vertical joints.

3. Space vent tubes in accordance with shop drawings, but not less than two vents per panel or approximately 1219 mm (4 feet) on centers.

E. Setting: Where shown, fill joints with cement mortar specified in Section

04 05 16, MASONRY GROUTING.

1. Clean surfaces forming beds and other joints for precast concrete panels of dust, dirt, and other foreign matter, and wet thoroughly to prevent suction before precast concrete, elements are set.

2. Set precast element level and true to line with uniform joints filled completely with mortar.

3. Rake out joints 25 mm (1-inch) deep for pointing or sealants.

4. Joints required to have only sealant to be kept free of mortar for full depth.

5. Keep exposed faces of precast concrete elements free of mortar.

6. Remove wedges, spacers, or other appliances which are likely to cause staining from joints.

7. Where parging is shown, parge back of elements solid with mortar. Apply paging without skips or holidays.

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F. Pointing: Wash and brush clean, leaving joints free from loose mortar, dust and other foreign material.

1. Carefully point with a slightly concave joint.

2. Mortar for pointing as specified in Section 04 05 16, MASONRY GROUTING

. Provide same material and color sand used in fabrication of precast concrete elements.

G. Sealing of Joints: Where shown and where required to make work watertight:

clean, dry and seal joints between precast concrete elements and between precast elements and adjoining materials as specified in Section 07 92 00, JOINT SEALANTS.

3.8 FIELD QUALITY CONTROL

A. Testing Agency: Contractor engaged qualified testing agency approved by

COR is to perform tests and inspections and prepare test reports.

B. Visually inspect field welds and test according to ASTM E165 or to

ASTM E709.

C. Report test results directly from testing agency within 7 days after testing and in writing to Contractor and COR.

D. As directed by COR, repair, or remove and replace work that does not comply with specified requirements.

E. Perform additional testing and inspecting, at no additional cost, to determine compliance of corrected work with specified requirements.

3.9 REPAIRS

A. When permitted by COR, repair damaged units.

B. Mix patching materials and repair units so cured patches blend with color, texture, and uniformity of adjacent exposed surfaces and show no apparent line of demarcation between original and repaired work, when viewed in typical daylight illumination from a distance of 6.1 m (20 feet).

C. Prepare and repair damaged galvanized coatings with galvanizing repair paint according to ASTM A780/A780M.

D. Remove and replace damaged units when repairs do not meet requirements.

E. Repair damaged units to meet acceptability of PCI MNL 117.

F. Wire brush, clean, and paint damaged prime painted components with the same type of shop primer.

3.10 CLEANING:

A. Clean surfaces of precast concrete to be exposed to view, as necessary, prior to shipping.

B. Clean mortar, plaster, fireproofing, weld slag, and any other deleterious material from concrete surfaces and adjacent materials immediately.

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C. Clean exposed surfaces of precast concrete units after erection and completion of joint treatment to remove weld marks, other markings, dirt, and stains.

1. Perform cleaning procedures, if necessary, according to precast concrete fabricator’s recommendations. Clean soiled precast concrete surfaces with detergent and water, using stiff fiber brushes and sponges, and rinse with clean water. Protect other work from staining or damage due to cleaning operations.

2. Do not use cleaning materials or processes that could change the appearance of exposed concrete finishes or damage adjacent materials.

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