Section 03 45 33.pdf

REPAIR TAXIWAY PAVEMENTS RM109145

NAS OCEANA, VIRGINIA BEACH, VA ePROJECTS WO #1635836

SECTION 03 45 33

PRECAST STRUCTURAL CONCRETE BOX CULVERTS

PART 1 GENERAL

The work under this section covers the requirements for materials, mixing, forming, placing, and curing reinforced precast non-prestressed reinforced concrete structures used for below grade construction. Option of cast-in-place concrete is included with this specification section.

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO LRFD (8th Edition; 2017) Bridge Design Specifications

AMERICAN CONCRETE INSTITUTE (ACI)

ACI 305R (2020) Guide to Hot Weather Concreting

ACI 306.1 (1990; R 2002) Standard Specification for Cold Weather Concreting

ACI 318 (2014; Errata 1-2 2014; Errata 3-5 2015;

Errata 6 2016; Errata 7-9 2017) Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14)

AMERICAN CONCRETE PIPE ASSOCIATION (ACPA)

ACPA QPC (2020) QCast Plant Certification Manual

AMERICAN WELDING SOCIETY (AWS)

AWS D1.1/D1.1M (2020; Errata 1 2021) Structural Welding Code - Steel

AWS D1.4/D1.4M (2011) Structural Welding Code - Reinforcing Steel

ASTM INTERNATIONAL (ASTM)

ASTM A27/A27M (2020) Standard Specification for Steel Castings, Carbon, for General Application

ASTM A36/A36M (2019) Standard Specification for Carbon Structural Steel

ASTM A47/A47M (1999; R 2022; E 2022) Standard Specification for Ferritic Malleable Iron

SECTION 03 45 33 Page 1 (REVISED PPI Addendum 6, 3/20/2024)

Castings

ASTM A123/A123M (2017) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

ASTM A153/A153M (2016a) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A307 (2021) Standard Specification for Carbon Steel Bolts, Studs, and Threaded Rod 60 000 PSI Tensile Strength

ASTM A325 (2014) Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength

ASTM A563 (2021; E 2022a) Standard Specification for Carbon and Alloy Steel Nuts

ASTM A615/A615M (2022) Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement

ASTM A767/A767M (2016) Standard Specification for Zinc-Coated (Galvanized) Steel Bars for Concrete Reinforcement

ASTM A780/A780M (2020) Standard Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings

ASTM A1064/A1064M (2022) Standard Specification for Carbon-Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete

ASTM C31/C31M (2022) Standard Practice for Making and Curing Concrete Test Specimens in the Field

ASTM C33/C33M (2018) Standard Specification for Concrete Aggregates

ASTM C39/C39M (2021) Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens

ASTM C94/C94M (2022a) Standard Specification for Ready-Mixed Concrete

ASTM C138/C138M (2017a) Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete

ASTM C143/C143M (2020) Standard Test Method for Slump of Hydraulic-Cement Concrete

ASTM C150/C150M (2022) Standard Specification for Portland

SECTION 03 45 33 Page 2

Cement

ASTM C171 (2020) Standard Specification for Sheet Materials for Curing Concrete

ASTM C173/C173M (2016) Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method

ASTM C192/C192M (2019) Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory

ASTM C231/C231M (2022) Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

ASTM C260/C260M (2010a; R 2016) Standard Specification for Air-Entraining Admixtures for Concrete

ASTM C295/C295M (2019) Standard Guide for Petrographic Examination of Aggregates for Concrete

ASTM C309 (2019) Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete

ASTM C311/C311M (2022) Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete

ASTM C443 (2021) Standard Specification for Joints for Concrete Pipe and Manholes, Using Rubber Gaskets

ASTM C494/C494M (2019; E 2022) Standard Specification for Chemical Admixtures for Concrete

ASTM C618 (2023) Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete

ASTM C989/C989M (2022) Standard Specification for Slag Cement for Use in Concrete and Mortars

ASTM C1064/C1064M (2017) Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete

ASTM C1107/C1107M (2020) Standard Specification for Packaged Dry, Hydraulic-Cement Grout (Nonshrink)

ASTM C1157/C1157M (2020a) Standard Performance Specification for Hydraulic Cement

ASTM C1167 (2022) Standard Specification for Clay Roof Tiles

ASTM C1260 (2021) Standard Test Method for Potential

SECTION 03 45 33 Page 3

Alkali Reactivity of Aggregates (Mortar-Bar Method)

ASTM C1433 (2020) Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers

ASTM C1433M (2020) Standard Specification for Precast Reinforced Concrete Monolithic Box Sections for Culverts, Storm Drains, and Sewers

ASTM C1567 (2022) Standard Test Method for Potential Alkali-Silica Reactivity of Combinations of Cementitious Materials and Aggregate (Accelerated Mortar-Bar Method)

ASTM C1602/C1602M (2022) Standard Specification for Mixing Water Used in Production of Hydraulic Cement Concrete

ASTM C1677 (2011) Standard Specification for Joints for Concrete Box, Using Rubber Gaskets

ASTM D1149 (2007; R 2018) Standard Test Methods for Rubber Deterioration - Cracking in an Ozone Controlled Environment

ASTM D5759 (2012; R 2020) Characterization of Coal Fly Ash and Clean Coal Combustion Fly Ash for Potential Uses

ASTM F436 (2011) Hardened Steel Washers

ASTM F844 (2019) Standard Specification for Washers, Steel, Plain (Flat), Unhardened for General Use

CSA GROUP (CSA)

CSA A23.4 (2016; R 2021) Precast Concrete - Materials and Construction

NATIONAL PRECAST CONCRETE ASSOCIATION (NPCA)

NPCA QC Manual (2017) Quality Control Manual for Precast and Prestressed Concrete Plants

1.2 MODIFICATION TO REFERENCE

In the ACI publications, reference to the "Building Official," the "Structural Engineer" and the "Architect/Engineer" must be interpreted to mean the Contracting Officer.

1.3 SUBMITTALS

Government approval is required for submittals with a "G" or "S" classification. Submittals not having a "G" or "S" classification are for

SECTION 03 45 33 Page 4

Contractor Quality Control approval. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Quality Control Procedures ; G

SD-02 Shop Drawings

Precast Box Culvert Shop Drawing And Design Calculation ; G

SD-03 Product Data

Corrosion Inhibitors ; G

Reinforcing Bars ; G

Wire ; G

Synthetic Fiber Reinforcement ; G

Admixtures

Structural Steel

Inserts

Rubber Gaskets ; G

SD-05 Design Data

Concrete Mix Design ; G

SD-06 Test Reports

Concrete Mix Design ; G

Fly Ash

Ground Granulated Blast-Furnace Slag

Aggregates

Concrete and Aggregate Quality Control Testing, G

Water

Cement; G

Qc Tests And Test Results ; G

SD-11 Closeout Submittals

Batch Ticket Information ; G

Construction Records ; G

SECTION 03 45 33 Page 5

1.4 QUALITY ASSURANCE

The precast concrete producer must be certified by the National Precast Concrete Association's or the American Concrete Pipe Association's Plant Certification Program prior to and during production of the products for this project.

1.4.1 QUALIFICATIONS

1.4.1.1 Manufacturer Qualifications

Select a precast concrete producer that has been in the business of producing precast concrete units similar to those specified for a minimum of 3 years. The precast concrete producer must maintain a permanent quality control department or retain an independent testing agency on a continuing basis.

1.4.1.2 Welding Qualifications

Provide AWS D1.1/D1.1M qualified welders who are currently certified at contract award date and have maintained their certificates over the past year.

1.4.2 REGULATORY REQUIREMENTS

Provide precast members in conformance with ACI 318 and ASTM C1433 except as modified herein.

1.4.3 CONCRETE MIX DESIGN

ACI 318 . The minimum compressive strength of concrete at 28 days must be 5000 psi , unless otherwise indicated. Add air-entraining admixtures at the mixer to produce 6 +/-0.5 percent air by volume.The maximum water cement ratio must be 0.40.

Sixty days minimum prior to concrete placement, submit a mix design for each strength and type of concrete.

Submit a complete list of materials including type; brand; source and amount of cement, complementary cementitious materials, synthetic fibers, and admixtures; and applicable reference specifications.

Submit mill test and all other test for cement, complementary cementitious materials, aggregates, and admixtures. Provide documentation of maximum nominal aggregate size, gradation analysis, percentage retained and passing sieve, and a graph of percentage retained verses sieve size.

Provide mix proportion data using at least three different water-cementitious material ratios for each type of mixture, which produce a range of strength encompassing those required for each type of concrete required. If source material changes, resubmit mix proportion data using revised source material. Provide only materials that have been proven by trial mix studies to meet the requirements of this specification, unless otherwise approved in writing by the Contracting Officer.

Indicate clearly in the submittal where each mix design is used when more than one mix design is submitted. Resubmit data on concrete components if the qualities or source of components changes.

For previously approved concrete mix designs used within the past twelve

(12) months, the previous mix design may be re-submitted without further trial batch testing if accompanied by material test data conducted within the last six months.

Obtain mix design approval from the contracting officer prior to concrete

SECTION 03 45 33 Page 6 placement.

1.4.4 RECORD REQUIREMENT

ASTM C94/C94M. Submit batch ticket information for each load of ready-mixed concrete.

1.5 DELIVERY, STORAGE, AND HANDLING

1.5.1 TRANSPORTATION

1.5.1.1 Transporting Members

Transport members in a manner to avoid excessive stresses that could cause cracking or other damage.

1.5.1.2 Lateral Deflection or Vibration

Any noticeable indication of lateral deflection or vibration during transportation must be corrected by rigid bracing between members or by means of lateral trussing.

1.5.2 STORAGE

1.5.2.1 Storage Areas

Storage areas for precast members must be stabilized, and suitable foundations must be provided, so differential settlement or twisting of members will not occur.

1.5.2.2 Stacked Members

Stacking is not permitted.

1.5.3 HANDLING OF MEMBERS

Provide lifting devices to ensure structural integrity during handling and installation. Lift holes are not permitted in box culvert sections. Use handling devices that do not require a hole through the box.

The location of pickup points for handling of the members and details of the pickup devices must be shown in shop drawings. Members must be handled only by means of approved devices at designated locations.

Members must be maintained in an upright position at all times and picked up and supported as shown in approved shop drawings.

PART 2 PRODUCTS

2.1 SYSTEM DESCRIPTION

This work includes designing, detailing, casting, reinforcing of the precast box culvert sections, headwalls, wingwalls, and their connections.

For culvert type, span, rise, and for culvert and wingwalls layouts refer to the project plans.

Box culvert sections shall be precast. Headwalls and wingwalls may be precast or cast-in-place.

Refer to the Section 33 40 00 for additional information.

SECTION 03 45 33 Page 7

2.1.1 DESIGN REQUIREMENTS

Provide reinforced concrete box section conforming to requirements of ASTM C1433M ASTM C1433 with the following modifications:

2.1.1.1 Design loading for STANDARD Type Precast Reinforced Concrete Box Culvert

STANDARD type box culverts are to be constructed beyond the paved or unpaved shoulder areas of runways, taxiways, towways, helipads, aprons or overruns. Refer to plans for culvert types.

STANDARD type culverts must be designed for combined earth dead load and AASHTO HS20 live load conditions.

Wingwalls and headwalls shall be designed accordingly.

2.1.1.2 Design Loading for AIRCRAFT RATED Type Precast Reinforced Concrete Box Culverts

AIRCRAFT RATED type box culverts are to be constructed within runways, taxiways, towways, helipads, aprons, overruns or shoulders paved or unpaved. Refer to plans for culvert types. Wingwalls and headwalls shall be designed accordingly.

AIRCRAFT RATED type culverts must be designed for the aircraft loads as described in the following:

a. Live Load. Structures must be designed for the maximum number of wheels that can fit onto the span considering the most critical assigned aircraft at its maximum gross weight. The design aircraft is KC-10A. The aircraft gear data will be provided by NAVFAC after contract award. In no case should the design be based on computed stress conditions less than those created by a wheel load of 100,000 lb (45,000 kg) at a contact pressure of 250 psi (1.72 MPa). Distribution of Live Load shall be per AASHTO requirements. Live load must include a magnification factor for impact.

b. Vertical load must include Dead Load, the weight of the column of earth of a width equal to the outside width dimension of the box section and a height equal to the depth of cover over the top of the section multiplied by the maximum soil/structure interaction factor of 1.15, and the superimposed load.

c. Angle of Internal Friction (phi) = 28 degrees

d. Unit Weight of Soil = 120 pcf

c. Coefficient of Lateral Earth Pressure (Ka) = 0.36

e. Ground Water Level = 3 feet below ground elevation

f. Horizontal design loads must include full geostatic and hydrostatic pressures for the soil parameters, water table, and depth of installation to be encountered. Lateral loads imposed by adjacent load applications and horizontal load components of vertical design loads must be considered per

ASTM C1433.

g. Each structural component must be designed for the load combination and positioning resulting in the maximum shear and moment for that particular component.

SECTION 03 45 33 Page 8

h. Design must also consider the live loads induced in the handling, installation, and backfilling of the culverts. Provide lifting devices to ensure structural integrity during handling and installation. Lift holes are not permitted. Use handling devices that do not require a hole through the box.

i. Structural design must be per Load Resistance Factor Design provisions given in AASHTO LRFD.

j. Foundation design shall be based on the allowable foundation bearing pressure of 1,500 psf. Alternatively, the ultimate (nominal) bearing resistance is 2,500 psf.

2.1.2 Precast Box Culvert Shop Drawing And Design Calculation

Prior to fabrication submit shop drawings for precast concrete units and/or cast-in-place designs and obtain approval by the Contracting Officer. Submittal must demonstrate that the applicable industry design standards have been met.

Shop drawings must represent a complete design, details and all dimensions, installation, and construction information in such detail as to enable the Contracting Officer to determine the adequacy of the proposed units for the intended purpose. Shop drawings must indicate joints and sealants between adjacent units, wingwalls and headwalls. All attachments must be detailed on the shop drawings.

The shop drawings must include but not limited to:

-strength properties for concrete, steel and other material, -all dead, live, handling, erection and other applicable loads used in the design.

-details of steel reinforcement size and placement -details of box culverts, wingwall and headwall attachments.

-signature and seal of the registered design professional who prepared the design.

For STANDARD type culverts submit cut sheets showing conformance to contract requirements.

For AIRCRAFT RATED type shop drawings must include design calculations prepared and sealed by a registered professional engineer.

Include in the calculations the analysis of units for handling stresses.

2.2 MATERIALS

Provide materials per requirement of ASTM C1433 unless specified herein.

2.2.1 CEMENTITIOUS MATERIALS

For exposed concrete, use one manufacturer and one source for each type of cement, ground slag, fly ash, and pozzolan.

2.2.1.1 Portland Cement

Provide cement that conforms to ASTM C150/C150M, Type I/II or II with tri-calcium aluminates (C3A) content less than 10 percent and a maximum cement-alkali content of 0.80 percent Na2Oe (sodium oxide) equivalent. Use one brand and type of cement for formed concrete having exposed-to-view finished surfaces. Cement shall be combined with supplementary cementing materials in the concrete mixture.

SECTION 03 45 33 Page 9

2.2.1.2 Blended Cements

Blended cements must conform to ASTM C595/C595M Type IP or IS and

ASTM C1157/C1157M .

Slag cement added to the Type IS blend must meet ASTM C989/C989M.

The pozzolan added to the Type IP blend must be ASTM C618 Class F fly ash and must be interground with the cement clinker. The manufacturer must state in writing that the amount of pozzolan in the finished cement will not vary more than plus or minus 5 mass percent of the finished cement from lot-to-lot or within a lot. The percentage and type of pozzolan used in the blend must not change from that submitted for the aggregate evaluation and mixture proportioning.

2.2.1.3 Fly Ash

ASTM C618, Class F, except that the maximum allowable loss on ignition must not exceed 6 percent.

Add with cement. Fly ash content must be a minimum of 15 percent by weight of cementitious material, provided the fly ash does not reduce the amount of cement in the concrete mix below the minimum requirements of local building codes. Where the use of fly ash cannot meet the minimum level, provide the maximum amount of fly ash permittable that meets the code requirements for cement content. Report the chemical analysis of the fly ash in accordance with ASTM C311/C311M. Evaluate and classify fly ash in accordance with ASTM D5759.

2.2.1.4 Ground Granulated Blast-Furnace Slag

ASTM C989/C989M, Grade 120.

2.2.2 WATER

Water must comply with the requirements of ASTM C1602/C1602M .

2.2.3 AGGREGATES

ASTM C33/C33M, except as modified herein. Furnish aggregates for exposed concrete surfaces from one source. Provide aggregates that do not contain any substance which may be deleteriously reactive with the alkalies in the cement. Submit test report showing compliance with ASTM C33/C33M.

Fine and coarse aggregates must show expansions less than 0.08 percent at 28 days after casting when testing in accordance with ASTM C1260. Should the test data indicate an expansion of 0.08 percent or greater, reject the aggregate(s) or perform additional testing using ASTM C1167 using the Contractor's proposed mix design. In this case, include the mix design low alkali portland cement and one of the following supplementary cementitious materials:

a. GGBF slag at a minimum of 40 percent of total cementitious

b. Fly ash or natural pozzolan at a minimum of total cementitious of

(1) 30 percent if (SiO2 plus Al2O3 plus Fe2O3) is 65 percent or more,

(2) 25 percent if (SiO2 plus Al2O3 plus Fe2O3) is 70 percent or more, SECTION 03 45 33 Page 10

(3) 20 percent if (SiO2 plus Al2O3 plus Fe2O3) is 80 percent or more,

(4) 15 percent if (SiO2 plus Al2O3 plus Fe2O3) is 90 percent or more.

If a combination of these materials is chosen, the minimum amount must be a linear combination of the minimum amounts above. Include these materials in sufficient proportion to show less than 0.08 percent expansion at 28 days after casting when tested in accordance with

ASTM C1567.

Aggregates must not possess properties or constituents that are known to have specific unfavorable effects in concrete when tested in accordance with ASTM C295/C295M.

2.2.4 GROUT

2.2.4.1 Nonshrink Grout

ASTM C1107/C1107M .

2.2.4.2 Cementitious Grout

Must be a mixture of portland cement, sand, and water. Proportion one part cement to approximately 2.5 parts sand, with the amount of water based on placement method. Provide air entrainment for grout exposed to the weather.

2.2.5 ADMIXTURES

2.2.5.1 Air-Entraining

ASTM C260/C260M.

2.2.5.2 Accelerating

ASTM C494/C494M, Type C or E.

2.2.5.3 Water Reducing

ASTM C494/C494M, Type A, E, or F.

2.2.6 CORROSION INHIBITORS

Corrosion inhibitors are considered "supplemental corrosion projection".

Corrosion inhibitor must be at least a 30 percent water solution of calcium nitrate (CNI). Accelerating and set adjusted versions are acceptable, however, the concrete set time effects and mixture workability shall be considered. Refer to admixture manufacturer recommendations for dosage for chloride protection levels. A minimum of 3.0 gallons per cubic yard of corrosion inhibitor must be used in the concrete mix , adjust the quantity of concrete mixing water for the mass of water in the admixture. Accelerating and set adjusted versions are acceptable. Concrete setting time and mixture workability shall be evaluated.

SECTION 03 45 33 Page 11

2.2.7 REINFORCEMENT

2.2.7.1 Reinforcing Bars

ASTM A615/A615M , Grade 60, hot-dip galvanized after fabrication per requirements of ASTM A767/A767M , Class I coating.

ASTM A1064/A1064M Continuous Hot-Dip Galvanized Steel Bars for Concrete Reinforcement is an acceptable alternative to ASTM A767/A767M Class 1 for this project.

Corrosion resistant reinforcing (CRR) steel, Class I and conform to AASHTO M 334M/M 334-17 Type 1035 CS with a minimum chromium content of 9.2% or UNS (Unified Numbering System for Metals and Alloys) Designation: S24100.

2.2.7.2 Wire

ASTM A1064/A1064M .

2.2.7.3 Welded Wire Reinforcement

ASTM A1064/A1064M .

2.2.7.4 Supports for Concrete Reinforcement

Include bolsters, chairs, spacers, and other devices necessary for proper spacing, supporting, and fastening reinforcement bars and wire in place.

Ensure legs of supports in contact with formwork for sections that will be exposed to weather are hot-dip galvanized after fabrication, plastic coated, or corrosion-resistant steel bar supports.

2.2.8 SYNTHETIC FIBER REINFORCEMENT

Provide fiber reinforced concrete in accordance with ASTM C1116 Type III, synthetic fiber reinforced concrete, and as follows. Synthetic reinforcing fibers must be 100 percent virgin monofilament polypropylene fibers. Provide fibers that have a specific gravity of 0.9, a minimum tensile strength of 70 ksi, graded per manufacturer, and specifically manufactured to an optimum gradation for use as concrete secondary reinforcement.Use a minimum of 1.5 pounds of fibers per cubic yard of concrete.

2.2.9 METAL ACCESSORIES

Metal accessories must be hot-dip galvanized per ASTM A123/A123M or

ASTM A153/A153M .

2.2.9.1 Inserts

ASTM A47/A47M, Grade 32510 , or ASTM A27/A27M Grade 60-30 . Submit product data.

2.2.9.2 Structural Steel

ASTM A36/A36M.

SECTION 03 45 33 Page 12

2.2.9.3 Bolts

ASTM A307; ASTM A325.

2.2.9.4 Nuts

ASTM A563.

2.2.9.5 Washers

ASTM F844 washers for ASTM A307 bolts, and ASTM F436 washers for ASTM A325 bolts.

2.2.10 RUBBER GASKETS

Provide rubber gaskets that meet the oil resistant gasket requirements of

ASTM C443.

Gaskets for box culvert sections shall conform to ASTM C1677. All gaskets shall conform to the ozone cracking resistance:

Upon exposure to 100 parts per million of ozone in air by volume at a strain of 20 percent and a temperature of 100 ± 2 degrees F in a test conducted otherwise in accordance with ASTM D1149, cracks shall not develop within 100 hours. Samples shall be wiped with solvent before the test to remove traces of surface impurities.

2.3 PRODUCTION QUALITY CONTROL PROCEDURES

Conform to testing, acceptance, fabrication, marking, etc. requirements of ASTM C1433 unless specified otherwise. Submit Quality Control Procedures established by the precast manufacturer in accordance with NPCA QC Manual and ACPA QPC. Show that the following QC tests are performed as required and in accordance with the ASTM standards indicated.

2.3.1 SLUMP

Perform a slump test for each 150 cu yd of concrete produced,or once a day, whichever comes first. Perform slump tests in accordance with

ASTM C143/C143M.

2.3.2 TEMPERATURE

Measure the temperature of fresh concrete when slump or air content tests are made and when compressive test specimens are made in accordance with

ASTM C1064/C1064M .

2.3.3 COMPRESSIVE STRENGTH

Make at least four compressive strength specimens for each 150 cubic yards of concrete of each mix in accordance with the following Standards:

ASTM C31/C31M, ASTM C192/C192M, ASTM C39/C39M.

2.3.4 AIR CONTENT

Perform tests for air content on air-entrained, wet-cast concrete for each 150 cu yd of concrete, but not less often than once each day when air-entrained concrete is used. Determine the air content in accordance with either ASTM C231/C231M or ASTM C173/C173M for normal weight aggregates.

SECTION 03 45 33 Page 13

2.3.5 UNIT WEIGHT

Perform tests for unit weight a minimum of once per week to verify the yield of batch mixes in accordance with ASTM C138/C138M.

2.3.6 TEST REPORTS

Submit the following:

2.3.6.1 Material Certifications or Laboratory Test Reports

Include mill tests and all other test data, for portland cement, blended cement, pozzolans, ground granulated blast furnace slag, aggregate, admixtures, and curing compound proposed for use on this project.

2.3.6.2 Mix Test

Submit reports showing that the mix has been successfully tested to produce concrete with the properties specified and will be suitable for the job conditions. Such tests may include compressive strength, flexural strength, plastic or hardened air content, freeze thaw durability, abrasion and absorption. Clearly detail in the specifications special tests for precast concrete or cast-in items.

2.3.6.3 Self-Consolidating Concrete

Submit sufficient documentation, when the use of self-consolidating concrete (SCC) is proposed, showing a minimum of 30-days production track records demonstrating that SCC is appropriate for casting of the product.

2.3.6.4 In-Plant QA/QC Inspection Reports

Submit inspection reports upon the request of the Contracting Officer.

2.3.7 IDENTIFICATION MARKINGS

Clearly mark each structural section in a permanent manner on the interior side of the section.

2.3.8 FABRICATION AND PLACEMENT

Perform fabrication in accordance with NPCA QC Manual or ACPA QPC unless specified otherwise.

2.3.8.1 Forms

Use forms, for manufacturing precast concrete products, of the type and design consistent with industry standards and practices. They should be capable of consistently providing uniform products and dimensions.

Construct forms so that the forces and vibrations to which the forms will be subjected can cause no product damage. Clean forms of concrete build-up after each use. Apply form release agents according to the manufacturers recommendations and do not allow to build up on the form casting surfaces.

2.3.8.2 Reinforcement

Follow applicable ASTM Standard or ACI 318 for placement and splicing. Fabricate cages of reinforcement either by tying the bars, SECTION 03 45 33 Page 14 wires or welded wire reinforcement into rigid assemblies or by welding, where permissible, in accordance with AWS D1.4/D1.4M . Position reinforcing as specified by the design and so that the concrete cover conforms to requirements.

The minimum cover of main reinforcing bars shall be:

top reinforcement of top slab 2-1/2" from the face of concrete;

bottom reinforcement of top slab 2 inches;

all other reinforcement 1-1/2 inches.

The tolerance on concrete cover must be one-third of that specified but not more than 1/2 inch. Take positive means to assure that the reinforcement does not move significantly during the casting operations.

2.3.8.3 Embedded Items

Position embedded items at locations specified in the shop drawings.

Perform welding in accordance with AWS D1.1/D1.1M when necessary. Hold rigidly in place inserts, plates, weldments, lifting devices and other items to be imbedded in precast concrete products so that they do not move significantly during casting operations. Submit product data sheets and proper installation instruction for anchors, lifting inserts and other devices. Clearly indicate the products dimensions and safe working load.

2.3.8.4 Concrete Mixing

ASTM C94/C94M. Mixing operations must produce batch-to-batch uniformity of strength, consistency, and appearance.

2.3.8.5 Concrete Placing

Deposit concrete into forms as near to its final location as practical.

Keep the free fall of the concrete to a minimum. Consolidate concrete in such a manner that segregation of the concrete is minimized and honeycombed areas are kept to a minimum. Use vibrators to consolidate concrete with frequencies and amplitudes sufficient to produce well consolidated concrete.

2.3.8.6 Cold Weather Concreting

Perform cold weather concreting in accordance with ACI 306.1 .

a. Provide adequate equipment for heating concrete materials and protecting concrete during freezing or near-freezing weather.

b. All concrete materials, reinforcement, forms, fillers, and ground with which concrete is to come in contact must be free from frost.

c. Do not use frozen materials or materials containing ice.

d. In cold weather the temperature of concrete at the time of placing must not be below 45 degrees F. Discard concrete that freezes before its compressive strength reaches 500 psi.

2.3.8.7 Hot Weather Concreting

Follow recommendations for hot weather concreting in ACI 305R . During hot weather, give proper attention to constituents, production methods, handling, placing, protection, and curing to prevent excessive concrete temperatures or water evaporation that could impair required strength or serviceability of the member or structure. The temperature of concrete at the time of placing must not exceed 90 degrees F.

SECTION 03 45 33 Page 15

2.3.8.8 Concrete Curing

Commence curing immediately following the initial set and completion of surface finishing.

2.3.8.8.1 Curing by Moisture Retention

Prevent moisture evaporation from exposed surfaces until adequate strength for stripping is reached by one of the following methods:

a. Cover with polyethylene sheets a minimum of 6 mils thick in accordance with ASTM C171.

b. Cover with burlap or other absorptive material and keep continually moist.

c. Use a membrane-curing compound, conforming to ASTM C309 and applied at a rate not less than 200 square ft/gallon, or in accordance with manufacturers' recommendations.

2.3.8.8.2 Curing with Heat and Moisture

Do not subject concrete to steam or hot air until after the concrete has attained its initial set. Apply steam, if used, within a suitable enclosure, which permits free circulation of the steam in accordance with CSA A23.4 . If hot air is used for curing, take precautions to prevent moisture loss from the concrete. The temperature of the concrete must not be permitted to exceed 150 degrees F. These requirements do not apply to products cured with steam under pressure in an autoclave.

2.3.9 SURFACE FINISH

Finish unformed surfaces of wet-cast precast concrete products as specified. If no finishing procedure is specified, finish such surfaces using a strike-off to level the concrete with the top of the form.

2.3.9.1 Formed Surfaces

Cast surfaces against approved forms following industry practices in cleaning forms, designing concrete mixes, placing and curing concrete.

Normal color variations, form joint marks, small surface holes caused by air bubbles, and minor chips and spalls will be accepted but no major imperfections, honeycombs or other major defects will be permitted.

2.3.9.2 Unformed Surfaces

Finish unformed surfaces with a vibrating screed, or by hand with a float.

Normal color variations, minor indentations, minor chips and spalls will be accepted. Major imperfections, honeycombs, or other major defects are not permitted.

2.3.9.3 Special Finishes

Troweled, broom or other finishes must be according to the requirements of project documents and performed in accordance with industry standards or supplier specifications. Submit finishes for approval when required by the project documents. The sample finishes must be approved prior to the start of production.

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2.3.10 ACCEPTANCE/REJECTION OF DEFECTS

2.3.10.1 Minor Defects

All honeycombed areas, chipped corners, air pockets over 1/4 inch in diameter, and other minor defects involve less than 36 square inches of concrete must be repaired. Form offsets of fins over 1/8 inch must be ground smooth. All unsound concrete must be removed from defective areas prior to repairing. All surfaces permanently exposed to view must be repaired by a blend of portland cement and white cement properly proportioned so that the final color when cured will be the same as adjacent concrete. Precast members containing hairline cracks which are visible and are less than 0.01 inches in width, may be accepted, except that cracks larger than 0.005 inches in width for surfaces exposed to the weather must be repaired.

2.3.10.2 Major Defects

Major defects are those which involve more than 36 square inches of concrete or expose reinforcing steel. If one or more major defects appear in a member, it will be rejected. Cracks of a width of more than

0.01 inch will be cause for rejection of the member.

2.3.11 REPAIRS

Repairs shall be performed by the contractor at no additional cost to the project.

2.3.11.1 Repairing Honeycombed Areas

When honeycombed areas are to be repaired, remove all loose material and cut back the areas into essentially horizontal or vertical planes to a depth at which coarse aggregate particles break under chipping rather than being dislodged. Use proprietary repair materials in accordance with the manufacturer's instructions. If a proprietary repair material is not used, saturate the area with water. Immediately prior to repair, the area should be damp, but free of excess water. Apply a cement-sand grout or an approved bonding agent to the chipped surfaces, followed immediately by consolidating an appropriate repair material into the cavity.

2.3.11.2 Repairing Minor Defects

Defects that will not impair the functional use or expected life of a precast concrete product may be repaired by any method that does not impair the product.

Major defects shall be evaluated by qualified personnel for possible effect on the functional use or the expected life of products. If it determined that the repairs are feasible the qualified personnel shall establish and perform the repair procedure.

PART 3 EXECUTION

3.1 FACTORY INSPECTION

At the option of the Contracting Officer, precast units may be inspected by the Contracting Officerprecastunits must be inspected by the QC Representative prior to being transported to the job site. The Contractor must give notice 14 days prior to the time the units will be available for plant inspection. Neither the exercise nor waiver of inspection at the

SECTION 03 45 33 Page 17 plant will affect the Government's right to enforce contractual provisions after units are transported or erected.

3.2 EXAMINATION

Prior to erection, and again after installation, precast members must be checked for damage, such as cracking, spalling, and honeycombing. As directed by the Contracting Officer, precast members that do not meet the surface finish requirements specified in paragraph SURFACE FINISH must be repaired, or removed and replaced with new precast members.

3.3 WELDING

AWS D1.1/D1.1M , AWS D1.4/D1.4M for welding connections and reinforcing splices. Protect the concrete and other reinforcing from heat during welding. Weld continuously along the entire area of contact. Grind smooth visible welds in the finished installation.

3.4 GALVANIZING REPAIR

Repair damage to galvanized coatings using ASTM A780/A780M zinc rich paint for galvanized surfaces damaged by handling, transporting, cutting, welding, bolting, or acid washing. Do not heat surfaces to which repair paint has been applied.

3.5 GROUTING

Clean and fill keyways between precast members, and other indicated areas, solidly with nonshrink grout or cementitious grout. Provide reinforcing where indicated. Remove excess grout before hardening.

3.6 CONSTRUCTION RECORDS

Complete construction records must be kept of the manufacturing, handling, and erection of the concrete members and submitted. Records must be kept for, but not limited to, the following items:

a. Specifications of material used in the manufacture of the members.

b. Records of the inspection of the members.

c. Records of any defects in the member and any corrective measures taken.

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SECTION 03 45 33 Page 18

1.5.3 HANDLING OF MEMBERS

2.1.2 Precast Box Culvert Shop Drawing And Design Calculation

2.2.10 RUBBER GASKETS