Amendment2specs.pdf

W912DQ-13-B-1000-0002

2 -- Amdt. 0002

The SOLICITATION is amended as follows:

NOTE: Deleted text is shown with strikethrough. Added text is shown with underline.

1. SPECIFICATIONS:

a. Narrative Change:

SECTION 01 30 00.00 23 GENERAL CONDITIONS AND SPECIAL REQUIREMENTS,

paragraph 1.9 Government Temporary Office is deleted in its entirety.

b. New Section:

SECTION 03 30 04 CONCRETE FOR MINOR STRUCTURES has been added. A copy of the new section accompanies this amendment.

2. DRAWINGS:

a. Narrative Change:

Drawing C-2 In GENERAL NOTES delete Note 2.1 in its entirety. See attached C-2.

3. All other terms and conditions remain unchanged and in full force.

W912DQ-13-B-1000

Amendment 0002

SECTION TABLE OF CONTENTS

DIVISION 03 - CONCRETE

SECTION 03 30 04

CONCRETE FOR MINOR STRUCTURES

04/06

PART 1 GENERAL

1.1 REFERENCES

1.2 STATE SPECIFICATIONS

1.3 SUBMITTALS

1.4 DESIGN AND PERFORMANCE REQUIREMENTS

1.4.1 Strength

1.4.1.1 Concrete Strength

1.4.1.2 CLSM Strength

1.4.1.3 Flowable Fill Strength

1.4.2 Finish of Formed Surfaces

1.4.3 CONSTRUCTION TOLERANCES

1.4.3.1 Backfill, Conduits, and Filling and Emptying Culverts

1.4.3.2 Concrete Appearance

1.4.4 Concrete Mixture Proportions

1.4.5 Controlled Low Strength Materials (CLSM), and Flowable Fill

Mixture Proportions

1.4.5.1 Controlled Low Strength Materials (CLSM)

1.4.5.2 Flowable Fill Mixture

PART 2 PRODUCTS

2.1 MATERIALS

2.1.1 Cementitious Materials

2.1.1.1 Portland Cement and Blended Hydraulic Cement

2.1.1.2 High Early Portland Cement

2.1.1.3 Pozzolan (Fly Ash)

2.1.1.4 Blended Hydraulic Cement

2.1.1.5 Ground Granualated Blast-Furnace Slag

2.1.2 Aggregates

2.1.2.1 Aggregate Sampling and Testing

2.1.2.2 Fine Aggregate

2.1.2.3 Coarse Aggregate

2.1.3 Admixtures

2.1.3.1 Air-Entraining Admixture

2.1.3.2 Accelerating Admixture

2.1.3.3 Water-Reducing or Retarding Admixture

2.1.4 Water

2.1.5 Reinforcing Steel

2.1.6 CONTRACTION JOINT STRIPS

2.1.7 Expansion Joint Filler Strips, Premolded

2.1.8 Joint Sealants - Field Molded Sealants

2.1.9 Waterstops

2.1.10 Formwork

2.1.11 Form Coatings

2.1.12 Vapor Barrier

03 30 04 - 1

2.1.13 Curing Materials

2.1.13.1 Impervious Sheet Materials

2.1.13.2 Membrane-Forming Curing Compound

2.1.13.3 Burlap and Cotton Mat

PART 3 EXECUTION

3.1 PREPARATION

3.1.1 General

3.1.2 Embedded Items

3.1.3 Formwork Installation

3.1.4 Vapor Barrier Installation

3.1.5 Production

3.1.5.1 Ready-Mixed

3.1.5.2 Batching and Mixing Equipment

3.1.6 Waterstops

3.2 CONVEYING AND PLACING

3.2.1 General

3.2.2 Consolidation

3.2.3 Cold-Weather Requirements

3.2.4 Hot-Weather Requirements

3.2.5 Flowable Fill Placement

3.3 FORM REMOVAL

3.4 CONCRETE FINISHING

3.4.1 General

3.4.2 Finishing Formed Surfaces

3.4.3 Finishing Unformed Surfaces

3.4.3.1 Float Finish

3.4.3.2 Broom Finish

3.4.3.3 Expansion and Contraction Joints

3.5 CURING AND PROTECTION

3.6 TESTS AND INSPECTIONS

3.6.1 General

3.6.2 Inspection Details and Frequency of Testing

3.6.2.1 Preparations for Placing

3.6.2.2 Air Content

3.6.2.3 Slump

3.6.2.4 Consolidation and Protection

3.6.3 Action Required

3.6.3.1 Placing

3.6.3.2 Air Content

3.6.3.3 Slump

3.6.3.4 Concrete Strength Testing

3.6.3.5 Flowable Fill Strength Testing

3.6.4 Reports

-- End of Section Table of Contents --

03 30 04 - 2

SECTION 03 30 04

CONCRETE FOR MINOR STRUCTURES

04/06

PART 1 GENERAL

Concrete specified elsewhere in the contract specifications and drawings, shall conform to the materials requirements specified herein for concrete and aggregates. Mixtures for special applications such as controlled low strength materials and flowable fill shall conform to the material requirements specified herein.

Controlled Low Strength Materials (CLSM): Controlled Low Strength Materials (CLSM) shall be used only where indicated. CLSM is used for applications as shown on the drawings. CLSM is concrete used for structural backfilling applications. CLSM is a pumpable or flowable Portland cement concrete used for backfilling around structures and pipe lines. Controlled Low Strength Materials shall conform to ACI 229 and the requirements specified herein. CLSM shall only be used where shown on the drawings, or specifically approved by the Contracting Officer.

FLOWABLE FILL: FLOWABLE FILL IS A FLOWABLE BACKFILL MIXTURE. FLOWABLE

FILL SHALL BE USED WHERE INDICATED ON DRAWINGS, OR WHERE SPECIFICALLY

APPROVED BY THE CONTRACTING OFFICER. FLOWABLE FILL SHALL NOT BE USED

FOR FILLING OR PLUGGING OF PIPELINES.

1.1 REFERENCES

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

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO M 182 (1991; R 2000) Burlap Cloth Made from Jute or Kenaf

ACI INTERNATIONAL (ACI)

ACI 308R (2001) Guide to Curing Concrete

ACI 117/117R (1990; R 2002) Standard Tolerances for Concrete Construction and Materials & Commentary

ACI 211.1 (1991; R 2002) Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete

ACI 117 (2006) Standard Specifications for Tolerances for Concrete Construction and Materials

03 30 04 - 3

ACI 309R (1996) Guide for Consolidation of Concrete

ACI 318/318R (2005; Errata 2005) Building Code Requirements for Structural Concrete and Commentary

ACI 347 (2004) Guide to Formwork for Concrete

AMERICAN HARDBOARD ASSOCIATION (AHA)

AHA A135.4 (1995) Basic Hardboard

ASTM INTERNATIONAL (ASTM)

ASTM A 185/A 185M (2006; E 2006) Standard Specification for Steel Welded Wire Reinforcement, Plain, for Concrete

ASTM A 615/A 615M (2007) Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement

ASTM D 1752 (2004a) Preformed Sponge Rubber and Cork Expansion Joint Fillers for Concrete Paving and Structural Construction

ASTM D 4832 (2002) Standard Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test Cylinders

ASTM C 1260 (2007) Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method)

ASTM C 143/C 143M (2005a) Standard Test Method for Slump of Hydraulic-Cement Concrete

ASTM C 150 (2007) Standard Specification for Portland Cement

ASTM C 171 (2003) Standard Specification for Sheet Materials for Curing Concrete

ASTM C 172 (2004) Standard Practice for Sampling Freshly Mixed Concrete

ASTM C 231 (2004) Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method

ASTM C 260 (2006) Standard Specification for Air-Entraining Admixtures for Concrete

ASTM C 309 (2007) Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete

ASTM C 31/C 31M (2006) Standard Practice for Making and Curing Concrete Test Specimens in the Field

03 30 04 - 4

ASTM C 33 (2007) Standard Specification for Concrete Aggregates

ASTM C 39/C 39M (2005e1) Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens

ASTM C 494/C 494M (2005a) Standard Specification for Chemical Admixtures for Concrete

ASTM C 595 (2007) Standard Specification for Blended Hydraulic Cements

ASTM D 5971-07 Standard Practice for Sampling Freshly Mixed Controlled Low-Strength Material

ASTM C 618 (2008) Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete

ASTM C 920 (2005) Elastomeric Joint Sealants

ASTM C 94/C 94M (2007) Standard Specification for Ready-Mixed Concrete

ASTM C 989 (2006) Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars

ASTM D 75 (2003) Standard Practice for Sampling Aggregates

ASTM E 96/E 96M (2005) Standard Test Methods for Water Vapor Transmission of Materials

NATIONAL READY MIXED CONCRETE ASSOCIATION (NRMCA)

NRMCA CPMB 100 (2000) Concrete Plant Standards

NRMCA QC 3 (2002) Quality Control Manual: Section 3, Plant Certifications Checklist:

Certification of Ready Mixed Concrete Production Facilities

NRMCA TMMB 100 (2001) Truck Mixer, Agitator and Front Discharge Concrete Carrier Standards

U.S. ARMY CORPS OF ENGINEERS (USACE)

COE CRD-C 400 (1963) Requirements for Water for Use in Mixing or Curing Concrete

COE CRD-C 572 (1974) Specifications for Polyvinylchloride Waterstops

1.2 STATE SPECIFICATIONS

MISSOURI HIGHWAY AND TRANSPORTATION COMMISSION (MoDOT), MISSOURI STANDARD

03 30 04 - 5

SPECIFICATIONS FOR HIGHWAY CONSTRUCTION, 2004 edition (including all subsequent supplements and updates), are referred to herein as State Specifications. Paragraphs pertaining to measurement and payment in the State Specifications shall not be used. References to State or Engineer shall be understood to be the Contracting Officer. The State Specifications form a part of this specification only to the extent referenced.

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. The following shall be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-03 Product Data

Air-Entraining Admixture Accelerating Admixture Water-Reducing or Retarding Admixture Reinforcing Steel Expansion Joint Filler Strips, Premolded

Manufacturer's literature is available from suppliers which demonstrates compliance with applicable specifications for the above materials.

Batch tickets

Batch tickets shall be submitted during the progress of the work. The batch tickets shall include the mix ID for the batch, quantity of ingredients batched, date and time of batching.

Batching and Mixing Equipment

Batching and mixing equipment will be accepted on the basis of manufacturer's data which demonstrates compliance with the applicable specifications.

Conveying and Placing Concrete

The methods and equipment for transporting, handling, depositing, and consolidating the concrete shall be submitted prior to the first concrete placement.

Formwork

Formwork design shall be submitted prior to the first concrete placement.

SD-06 Test Reports

Aggregates; G RO

Aggregates will be accepted on the basis of certificates of compliance and test reports that show the material(s) meets the quality and grading requirements of the specifications under which it is furnished.

03 30 04 - 6

Concrete Mixture Proportions; G, DO

Mixture Proportioning submittal shall be made for each mixture proposed for use in the work. Submittals shall be made for concrete, and other mixtures proposed for use. The contractor shall submit the mixture proportions conforming to specified requirements 30 days prior to placement of concrete, CLSM, Flowable fill, and other mixtures. Certified test reports shall be submitted to verify that the mixture proportions selected will produce concrete, CLSM, Flowable fill, and other mixtures of the quality specified.

Flowable Fill Mixture Proportions; G, DO

Mixture Proportioning submittal shall be made for each mixture proposed for use in the work. Submittals shall be made for Flowable fill and other mixtures proposed for use. The contractor shall submit the mixture proportions conforming to specified requirements 30 days prior to placement of concrete, CLSM, Flowable fill, and other mixtures. Certified test reports shall be submitted to verify that the mixture proportions selected will produce concrete, CLSM, Flowable fill, and other mixtures of the quality specified.

SD-07 Certificates

Cementitious Materials

Certificates of compliance attesting that the concrete materials meet the requirements of the specifications shall be submitted in accordance with the Special Clause "CERTIFICATES OF COMPLIANCE".

Cementitious material will be accepted on the basis of a manufacturer's certificate of compliance, accompanied by mill test reports that the material(s) meet the requirements of the specification under which it is furnished.

Aggregates

Aggregates will be accepted on the basis of certificates of compliance and tests reports that show the material(s) meet the quality and grading requirements of the specifications under which it is furnished.

1.4 DESIGN AND PERFORMANCE REQUIREMENTS

The Government will maintain the option to sample and test all materials used in the work to determine compliance with the specifications. The Contractor shall provide facilities and labor as may be necessary to assist the Government in procurement of representative test samples. Samples of aggregates will be obtained at the point of batching in accordance with ASTM D 75. Concrete will be sampled in accordance with ASTM C 172. Slump and air content will be determined in accordance with ASTM C 143/C 143M and ASTM C 231, respectively, when cylinders are molded. Compression test specimens will be made, cured, and transported in accordance with ASTM C 31/C 31M. Compression test specimens will be tested in accordance with ASTM C 39/C 39M. Samples for strength tests will be taken not less than once each shift in which concrete is produced. A minimum of three specimens will be made from each sample; two will be tested at 28 days for acceptance, and one will be tested at 7 days for information.

03 30 04 - 7

1.4.1 Strength

Acceptance test results will be the average strengths of two specimens tested at 28 days.

1.4.1.1 Concrete Strength

The strength of the concrete will be considered satisfactory so long as the average of three consecutive acceptance test results equal or exceed the specified compressive strength, f'c, and no individual acceptance test result falls below f'c by more than 500 psi.

1.4.1.2 CLSM Strength

The strength of the CLSM will be considered satisfactory so long as the average of three consecutive acceptance test results equal or exceed the specified compressive strength, f'c.

1.4.1.3 Flowable Fill Strength

The strength of the Flowable Fill will be considered satisfactory so long as the average of three consecutive acceptance test results equal or exceed the specified compressive strength, f'c, and no test result falls below the specifed compressive strength by more than 25 psi. Flowable fill strength testing shall be performed in accordance with ASTM D 4832.

1.4.2 Finish of Formed Surfaces

A Class "C" finish shall apply to all concrete surfaces except those specified to receive a Class "D" finish. A Class "D" finish shall apply to all surfaces which will be permanently concealed after construction. The surface requirements for the classes of finish required shall be as specified in ACI 347.

1.4.3 CONSTRUCTION TOLERANCES

Construction tolerances shall be followed as indicated in ACI 117. Except as specified otherwise, a plus tolerance increases and a minus tolerance decreases the dimension to which it applies. A tolerance without sign means plus or minus. Where only one sign is specified, there is no limit in the other direction. Tolerances are not cumulative. The most restrictive tolerance will control. Tolerances shall not extend the structure beyond legal boundaries.

a. Level and grade tolerance measurements of slabs shall be made as soon as possible after finishing. When forms or shoring are used, the measurements shall be made prior to removal.

b. Construction tolerances shall meet the requirements of ACI 117/117R and any of the following requirements that are applicable.

1.4.3.1 Backfill, Conduits, and Filling and Emptying Culverts

Water Conveying:

Lateral alignment Centerline alignment 1/2 inch

03 30 04 - 8

Inside dimensions 0.005 times inside dimension

Level alignment Profile grade 1/2 inch

Cross-Sectional dimension Tunnel and culvert lining - 0 inch

1.4.3.2 Concrete Appearance

Permanently exposed surfaces shall be cleaned, if stained or otherwise discolored, by a method that does not harm the concrete and that is approved by the Contracting Officer.

1.4.4 Concrete Mixture Proportions

The total cementitious material content for all concrete shall be at least 564 lb/cubic yard.

Concrete mixture proportions shall be the responsibility of the Contractor. Trial mixtures having proportions, consistencies, and air content suitable for he work shall be made based on methodology described in ACI 211.1. Mixture proportions shall include the dry weights of cementitious material(s); the nominal maximum size of the coarse aggregate;

the specific gravities, aborptions, and saturated surface-dry weights of fine and coarse aggregates; the quantities, types and names of admixtures;

and quantity of water per cubic yard of concrete. All materials included in the mixture proportions shall be of the same type and from the same source as will be used on the project. Specified compressive strength f'c shall be 4,000 psi at 28 days. The maximum nominal size coarse aggregate shall be 3/4 inch, in accordance with ACI 318/318R. The air content shall be between 4.5 and 7.5 percent. The slump shall be between 2 and 5 inches. The maximum water cement ratio shall be 0.4.

1.4.5 Controlled Low Strength Materials (CLSM), and Flowable Fill Mixture Proportions

1.4.5.1 Controlled Low Strength Materials (CLSM)

Controlled Low Strength Materials (CLSM) is concrete or mortar used for structural backfill applications. Materials used in producing CLSM shall conform to the requirements specified herein for concrete. CLSM shall be air entrained. Design air content shall conform to the requirements herein for concrete. CLSM shall conform to ACI 229 and the requirements specified herein. Specified compressive strength f'c shall be at least 1,000 psi at 28 days. The cementitious material content of CLSM shall be measured by weight. The cementitious material content for CLSM shall conform to ACI

229. Aggregates shall be evaluated for potential alkali-aggregate reactivity. If pozzolan or GGBF slag is required to mitigate potential alkali-aggregate reactivity, the percentage by mass determined from the Aggregate Reactivity testing shall be used in the mixture proportioning studies. Trial batches and testing of mixtures shall be the responsibility of the Contractor. Samples of aggregates shall be obtained in accordance with the requirements of ASTM D 75. Mixture proportions shall include the dry weights of cementitious material(s); the saturated surface-dry weights of fine aggregate; the quantities, types, and names of admixtures; and quantity of water per cubic yard of mixture. All materials included in the mixture proportions shall be of the same type and from the same source as will be used for the project.

03 30 04 - 9

1.4.5.2 Flowable Fill Mixture

Materials for use in flowable fill shall conform to the requirements herein for concrete. Flowable fill shall have a compressive strength of at least 100 psi at 28 days age. Cementitious materials content, aggregate, and water in flowable fill shall be measured by weight. Flowable fill shall contain a cementitious materials content of at least 100 pounds of Portland cement per cubic yard of mixture, and at least 275 pounds of Class F fly ash per cubic yard of mixture. Flowable fill shall contain approximately 2795 pounds of concrete fine aggregate (sand) per cubic yard of mixture in saturated surface dry condition (SSD). The mixture shall contain less than 370 pounds of water. The mixture shall contain 2-ounces of air entrainig admixtures per cubic yard of mixture, and may include a water reducing admixture. Flowable fill may contain a water reducing admixture (WRA) as required to produce a cohesive flowable mixture.

Flowable fill shall be proportioned to provide the following consistency requirement: The fresh mixture shall not be thin and watery, but shall have a consistency similar to that of batter. It shall be tested by filling an open-ended 3-inch diameter, 6-inch high cylinder to the top with the mixture and immediately pulling the cylinder straight up. The correct consistency will produce an approximate 8-inch diameter circular-type spread with no segregation. Shrinkage of mix design shall be verified to be less than or equal to 0.035% using modified ASTM C 157 (28 day). Testing duration is 28 days and shall be provided by Contractor prior to flowable fill placement. If shrinkage criteria exceeded the Contractor shall develop at the Contractor's expense, a mix design capable of achieving shrinkage requirement of less than 0.035%, f'c greater than or equal to 100psi and a permeability of less than 0.00005 cm/sec, at Contractor's expense.

PART 2 PRODUCTS

2.1 MATERIALS

2.1.1 Cementitious Materials

Cementitious Materials shall be Portland cement in combination with pozzolan (fly ash) or ground granulated blast furnace slag, or shall be blended hydraulic cement. Use of cementitious materials in concrete which will have surfaces exposed in the completed structure shall be restricted so there is no change in color, source, or type of cementitious material.

Cementitious materials shall conform to the appropriate specifications listed:

2.1.1.1 Portland Cement and Blended Hydraulic Cement

ASTM C 150, Type I or II, meeting the low alkali requirement.

2.1.1.2 High Early Portland Cement

ASTM C 150, Type III, with C3A limited to 8 percent, meeting the low alkali requirement may be used only when specifically approved in writing.

2.1.1.3 Pozzolan (Fly Ash)

Pozzolan (Fly Ash) shall conform to ASTM C 618, Class F, including the

03 30 04 - 10 optional requirements for drying shrinkage, uniformity, and effectivesness in controlling Alkali-Silica reaction and shall have a loss on ignition not exceeding 3 percent. Class F fly ash shall have a Calcium Oxide (CaO) content of less than 8 percent. Fly ash if used, shall be used in the range of 25 to 40 percent of the total cementitious material by weight.

2.1.1.4 Blended Hydraulic Cement

Blended cement shall conform to ASTM C 595, Type IP, including the optional requirement for mortar expansion. If blended cements are used, they shall be used as suupplied by the manufacturer. Blended cements shall not be proportioned with other cementitious materials.

2.1.1.5 Ground Granualated Blast-Furnace Slag

Ground Granulated Blast-Furnace Slag shall conform to ASTM C 989, Grade 100 or Grade 120. Ground Granulated Blast-Furnace Slag if used, shall be used in the range of 40 to 50 percent of the total cementitious material by weight.

2.1.2 Aggregates

Aggregates shall consist of clean, hard, uncoated particles meeting the quality and gradation requirements of ASTM C 33, and the other requirements specified herein. Coarse and fine aggregates shall be produced from a current MoDOT State approved Portland cement concrete aggregate source for use in bridges and concrete pavements. Aggregates shall have a satisfactory service record of at least 5 years successful service in three paving projects. Aggregate sources which have demonstrated unsatisfactory freeze-thaw durability in past work, as evidenced by excessive pop-outs or "D" cracking, shall not be permitted for use in the work. Aggregates shall conform to the following.

2.1.2.1 Aggregate Sampling and Testing

Sampling and testing of aggregates shall be the Contractor's responsibility. All aggregate sampling and testing shall be accomplished by an appproved, independent, commercial materials testing laboratory as specified in ASTM C 1260. Laboratory test reports shall be certified by the testing laboratory.

2.1.2.2 Fine Aggregate

Fine aggregate shall consist of natural sand, manufactured sand, or a combination of the two, and shall be composed of clean, hard, durable particles. Fine aggregates shall meet MoDOT specification Section 1005.

Manufactured sand if used, shall be produced from the same source as the course aggregates. Fine aggregate shall conform to the quality and gradation requirements of ASTM C 33 and the requirements herein. The sum of all shale and clay lumps shall be less than 0.25% by weight. The sum of all coal and lignite shall be less than 0.25% by weight.

2.1.2.3 Coarse Aggregate

Coarse aggregate shall meet MoDOT Specification 1005 requirements for coarse aggregate in structures. Aggregate shall be obtained from rock of uniform quality. Coarse aggregate shall be sound durable, free of objectionable coatings and dust. Use of chemical treatments, surfactants, or other chemicals introduced to the aggregates for dust contro or other

03 30 04 - 11 purposes shall not be permitted. The nominal size of the coarse aggregate shall be 3/4-inch. Coarse aggregate shall conform to ASTM C 33, Class 5S, size designation 67, and the requirements herein. Coarse aggregate shall not contain more than 0.2 percent by weight of white tripolitic shert that has a specific, saturated surface dry, of less than 2.40. Tripolitic chert is the white porous siliceous from of weathered chert found in nodules and beds within some limestone sources. Total amount of all types of chert shall be less than 1.5 percent by weight. Aggregates shall have an absorption less than 2.0 percent.

2.1.3 Admixtures

Admixtures to be used, when required or approved, shall comply with the appropriate specification listed. Chemical admixtures that have been in storage at the project site for longer than 6 months or that have been subjected to freezing shall be retested at the expense of the contractor at the request of the Contracting Officer and shall be rejected if test results are not satisfactory.

2.1.3.1 Air-Entraining Admixture

Air-entraining admixture shall meet the requirements of ASTM C 260.

2.1.3.2 Accelerating Admixture

Accelerators shall meet the requirements of ASTM C 494/C 494M, Type C or E., except that calcium chloride or admixtures containing calcium chloride shall not be used.

2.1.3.3 Water-Reducing or Retarding Admixture

Water-reducing or retarding admixture shall meet the requirements of ASTM C 494/C 494M, Type A, B, or D. High-range water reducing admixture Type F or G may be used only when approved, approval being contingent upon particular placement requirements as described in the Contractor's Quality Control Plan.

2.1.4 Water

Water for mixing and curing shall be fresh, clean, potable, and free from injurious amounts of oil, acid, salt, or alkali, except that unpotable water may be used if it meets the requirements of COE CRD-C 400.

2.1.5 Reinforcing Steel

Reinforcing steel bar shall conform to the requirements of ASTM A 615/A 615M, Grade 60. Welded steel wire fabric shall conform to the requirements of ASTM A 185/A 185M. Details of reinforcement not shown shall be in accordance with ACI 318/318R, Chapters 7 and 12. See SECTION 03 20 01.00 10 for concrete reinforcement requirements.

2.1.6 CONTRACTION JOINT STRIPS

Contraction joint strips shall be 1/8 inch thick tempered hardboard conforming to AHA A135.4, Class 1. In lieu of hardboard strips, rigid polyvinylchloride (PVC) or high impact polystyrene (HIPS) insert strips specifically designed to induce controlled cracking in slabs on grade may be used. Such insert strips shall have removable top section.

03 30 04 - 12

2.1.7 Expansion Joint Filler Strips, Premolded

Expansion joint filler strips, premolded shall be sponge rubber, if required in the work as shown on the drawings, conforming to ASTM D 1752, Type I.

2.1.8 Joint Sealants - Field Molded Sealants

Joint sealants - field molded sealants, if required in the work as shown on the drawings, shall conform to ASTM C 920, Type M or S, Grade NS, Class 25, use NT for vertical joints and Type M or S, Grade P, Class 25, use T for horizontal joints. Bond-breaker material shall be polyethylene tape, coated paper, metal foil, or similar type materials. The backup material shall be compressible, nonshrink, nonreactive with the sealant, and a nonabsorptive material such as extruded butyl or polychloroprene foam rubber. Immediately prior to installation of field-molded sealants, the joint shall be cleaned of all debris and further cleaned using water, chemical solvents, or other means as recommended by the sealant manufacturer or directed.

2.1.9 Waterstops

Waterstops, if required in the work as shown on the drawings, shall conform to COE CRD-C 572.

2.1.10 Formwork

The design and engineering of the formwork as well as its construction, shall be the responsibility of the Contractor.

2.1.11 Form Coatings

Forms for exposed surfaces shall be coated with a nonstaining form oil, which shall be applied shortly before concrete is placed.

2.1.12 Vapor Barrier

Vapor barrier, if required in the work as shown on the drawings, shall be polyethylene sheeting with a minimum thickness of 10 mils or other equivalent material having a vapor permeance rating not exceeding 0.5 perms as determined in accordance with ASTM E 96/E 96M.

2.1.13 Curing Materials

Curing materials shall conform to the following requirements.

2.1.13.1 Impervious Sheet Materials

Impervious sheet materials, ASTM C 171, type optional, except polyethylene film, if used, shall be white opaque.

2.1.13.2 Membrane-Forming Curing Compound

ASTM C 309, Type 1-D or 2, Class A or B.

2.1.13.3 Burlap and Cotton Mat

Burlap and cotton mat used for curing shall conform to AASHTO M 182.

03 30 04 - 13

PART 3 EXECUTION

3.1 PREPARATION

3.1.1 General

Construction joints shall be prepared to expose coarse aggregate, and the surface shall be clean, damp, and free of laitance. Ramps and walkways, as necessary, shall be constructed to allow safe and expeditious access for concrete and workmen. Snow, ice, standing or flowing water, loose particles, debris, and foreign matter shall have been removed. Earth foundations shall be satisfactorily compacted. Spare vibrators shall be available. The entire preparation shall be accepted by the Government prior to placing.

3.1.2 Embedded Items

Reinforcement shall be secured in place; joints, anchors, and other embedded items shall have been positioned. Internal ties shall be arranged so that when the forms are removed the metal part of the tie will be not less than 2 inches from concrete surfaces permanently exposed to view or exposed to water on the finished structures. Embedded items shall be free of oil and other foreign matters such as loose coatings or rust, paint, and scale. The embedding of wood in concrete will be permitted only when specifically authorized or directed. All equipment needed to place, consolidate, protect, and cure the concrete shall be at the placement site and in good operating condition.

3.1.3 Formwork Installation

Forms shall be properly aligned, adequately supported, and mortar-tight.

The form surfaces shall be smooth and free from irregularities, dents, sags, or holes when used for permanently exposed faces. All exposed joints and edges shall be chamfered, unless otherwise indicated.

3.1.4 Vapor Barrier Installation

Vapor barriers, if required in the work as shown on the drawings, shall be applied over gravel fill. Edges shall be lapped not less than 6 inches.

All joints shall be sealed with pressure-sensitive adhesive not less than 2 inches wide. The vapor barrier shall be protected at all times to prevent injury or displacement prior to and during concrete placement.

3.1.5 Production

3.1.5.1 Ready-Mixed

Concrete, CLSM and Flowable Fill shall be furnished from a ready-mixed concrete plant. Ready-mixed material shall conform to ASTM C 94/C 94M except as otherwise specified. Ready-mixed concrete shall be batched, mixed, and transported in accordance with ASTM C 94/C 94M, except as otherwise specified. Truck mixers, agitators, and nonagitating transporting units shall comply with NRMCA TMMB 100. Ready-mix plant equipment and facilities shall be certified in accordance with NRMCA QC 3.

Batch tickets shall be submitted for each load of ready-mixed concrete.

3.1.5.2 Batching and Mixing Equipment

The batching plant shall be located off site close to the project. The

03 30 04 - 14 batching, mixing and placing system shall have a capacity of at least 50 cubic yards per hour. The batching plant shall conform to the requirements of NRMCA CPMB 100 and as specified; however, rating plates attached to batch plant equipment are not required. All water shall be batched to the mixer at the plant. Water shall not be added to the mix at the placing site.

3.1.6 Waterstops

Waterstops shall be installed in conformance with the locations and details shown on the drawings using materials and procedures specified in Section

03 15 13.00 10 EXPANSION JOINTS, CONTRACTION JOINTS, AND WATERSTOPS.

3.2 CONVEYING AND PLACING

Conveying and placing concrete shall conform to the following requirements.

3.2.1 General

Concrete placement shall not be permitted when weather conditions prevent proper placement and consolidation without approval. When concrete is mixed and/or transported by a truck mixer, the concrete shall be delivered to the site of the work and discharge shall be completed within 1-1/2 hours or 45 minutes when the placing temperature is 85 degrees F or greater unless a retarding admixture is used. Concrete shall be conveyed from the mixer to the forms as rapidly as practicable by methods which prevent segregation or loss of ingredients. Concrete shall be in place and consolidated within 15 minutes after discharge from the mixer. Concrete shall be deposited as close as possible to its final position in the forms and be so regulated that it may be effectively consolidated in horizontal layers 18 inches or less in thickness with a minimum of lateral movement.

The placement shall be carried on at such a rate that the formation of cold joints will be prevented.

3.2.2 Consolidation

Consolidation of concrete shall conform to ACI 309R and the requirements specified herein. Each layer of concrete shall be consolidated by rodding, spading, or internal vibrating equipment. Internal vibration shall be systematically accomplished by inserting the vibrator through the fresh concrete in the layer below at a uniform spacing over the entire area of placement. The distance between insertions shall be approximately 1.5 times the radius of action of the vibrator and overlay the adjacent, just-vibrated area by a few inches. The vibrator shall penetrate rapidly to the bottom of the layer and at least 6 inches into the layer below, if such a layer exists. It shall be held stationary until the concrete is consolidated and then withdrawn slowly at the rate of about 3 inches per second.

3.2.3 Cold-Weather Requirements

No concrete placement shall be made when the ambient temperature is below 35 degrees F or if the ambient temperature is below 40 degrees F and falling. Suitable covering and other means as approved shall be provided for maintaining the concrete at a temperature of at least 50 degrees F for not less than 72 hours after placing and at a temperature above freezing for the remainder of the curing period. Salt, chemicals, or other foreign materials shall not be mixed with the concrete to prevent freezing. Any concrete damaged by freezing shall be removed and replaced at the expense

03 30 04 - 15 of the contractor.

3.2.4 Hot-Weather Requirements

When the rate of evaporation of surface moisture, as determined by use of Figure 1 of ACI 308R, is expected to exceed 0.2 psf per hour, provisions for windbreaks, shading, fog spraying, or covering with a light-colored material shall be made in advance of placement, and such protective measures shall be taken as quickly as finishing operations will allow.

3.2.5 Flowable Fill Placement

Flowable fill shall be placed as backfill where indicated on drawings.

Flowable fill shall be placed as noted in Sections 3.2.1, 3.2.3, 3.2.3 with one exception, no vibrator shall be used to consolidate flowable fill.

Flowable fill is self consolidating. Care shall be taken to prevent the movement of any structure from designated location or the intrusion of flowable fill into undesirable locations. If such a movement or intrusion occurs, the Government's engineer may require the affected structure to be excavated and replaced to the proper grade at the Contractor's expense.

Where flowable fill is placed in multiple layers, the base layer shall be roughened and all loose and foreign material removed before placing the next layer.

3.3 FORM REMOVAL

Forms shall not be removed before the expiration of 24 hours after concrete placement except where otherwise specifically authorized. Supporting forms and shoring shall not be removed until the concrete has cured for at least 5 days. When conditions on the work are such as to justify the requirement, forms will be required to remain in place for longer periods.

3.4 CONCRETE FINISHING

3.4.1 General

No finishing or repair will be done when either the concrete or the ambient temperature is below 50 degrees F.

3.4.2 Finishing Formed Surfaces

All fins and loose materials shall be removed, and surface defects including tie holes shall be filled. All honeycomb areas and other defects shall be repaired. All unsound concrete shall be removed from areas to be repaired. Surface defects greater than 1/2 inch in diameter and holes left by removal of tie rods in all surfaces not to receive additional concrete shall be reamed or chipped and filled with dry-pack mortar. The prepared area shall be brush-coated with an approved epoxy resin or latex bonding compound or with a neat cement grout after dampening and filled with mortar or concrete. The cement used in mortar or concrete for repairs to all surfaces permanently exposed to view shall be a blend of portland cement and white cement so that the final color when cured will be the same as adjacent concrete.

3.4.3 Finishing Unformed Surfaces

All unformed surfaces that are not to be covered by additional concrete or backfill shall be float finished to elevations shown, unless otherwise specified. Surfaces to receive additional concrete or backfill shall be

03 30 04 - 16 brought to the elevations shown and left as a true and regular surface.

Exterior surfaces shall be sloped for drainage unless otherwise shown.

Joints shall be carefully made with a jointing tool. Unformed surfaces shall be finished to a tolerance of 3/8 inch for a float finish as determined by a 10 foot straightedge placed on surfaces shown on the plans to be level or having a constant slope. Finishing shall not be performed while there is excess moisture or bleeding water on the surface. No water or cement shall be added to the surface during finishing.

3.4.3.1 Float Finish

As a first finishing operation for unformed surfaces, all surfaces shall receive an initial float finish prepared as follows. No water, cement, or mortar shall be added to the surface during the finishing operation.

Surfaces to be float finished shall be screeded and darbied or bullfloated to eliminate the ridges and to fill in the voids left by the screed. In addition, the darby or bullfloat shall fill all surface voids and only slightly embed the coarse aggregate below the surface of the fresh concrete. When the water sheen disappears and the concrete will support a person's weight without deep imprint, floating should be completed.

Floating should embed large aggregates just beneath the surface, remove slight imperfections, humps, and voids to produce a plane surface, compact the concrete, and consolidate mortar at the surface. Floating may be performed by use of suitable hand floats or power-driven equipment. Hand floats shall be made of magnesium or aluminum.

3.4.3.2 Broom Finish

A broom finish shall be applied as the final surface texturing for exterior surfaces which will be subject to vehicle or pedestrian traffic. The concrete shall be screeded and floated to required finish plane with no coarse aggregate visible. After surface moisture disappears, the surface shall be broomed or brushed with a broom or fiber bristle brush in a direction transverse to that of the main traffic or as directed.

3.4.3.3 Expansion and Contraction Joints

Expansion and contraction joints shall be made in accordance with the details shown or as otherwise specified. Expansion and contraction joints shall be provided at locations matching and aligned with joints in the existing adjacent concrete surfaces, unless otherwise indicated. Expansion and contraction joints shall be cut or formed as required to match the joint size and shapes in the adjacent concrete surfaces.

3.5 CURING AND PROTECTION

Beginning immediately after placement and continuing for at least 14 days, all concrete shall be cured and protected from premature drying, extremes in temperature, rapid temperature change, freezing, mechanical damage, and exposure to rain or flowing water. All materials and equipment needed for adequate curing and protection shall be available and at the site of the placement prior to the start of concrete placement. Preservation of moisture for concrete surfaces not in contact with forms shall be accomplished by one of the following methods:

a. Continuous sprinkling or ponding.

b. Application of absorptive mats or fabrics kept continuously wet.

03 30 04 - 17

c. Application of sand kept continuously wet.

d. Application of impervious sheet material conforming to ASTM C 171.

e. Application of membrane-forming curing compound conforming to ASTM C 309, Type 1-D, on surfaces permanently exposed to view and Type 2 on other surfaces shall be accomplished in accordance with manufacturer's instructions.

The preservation of moisture for concrete surfaces placed against wooden forms shall be accomplished by keeping the forms continuously wet for 14 days. If forms are removed prior to end of the required curing period, other curing methods shall be used for the balance of the curing period.

During the period of protection removal, the temperature of the air in contact with the concrete shall not be allowed to drop more than 25 degrees F within a 24 hour period.

3.6 TESTS AND INSPECTIONS

3.6.1 General

The individuals who sample and test concrete as required in this specification shall have demonstrated a knowledge and ability to perform the necessary test procedures equivalent to the ACI minimum guidelines for certification of Concrete Field Testing Technicians, Grade I.

3.6.2 Inspection Details and Frequency of Testing

3.6.2.1 Preparations for Placing

Foundation or construction joints, forms, and embedded items shall be inspected in sufficient time prior to each concrete placement by the Contractor to certify that it is ready to receive concrete.

3.6.2.2 Air Content

Air content shall be checked at least once during each shift that concrete is placed for each class of concrete required. Samples shall be obtained in accordance with ASTM C 172 and tested in accordance with ASTM C 231.

3.6.2.3 Slump

Slump shall be checked once during each shift that concrete is produced for each class of concrete required. Samples shall be obtained in accordance with ASTM C 172 and tested in accordance with ASTM C 143/C 143M.

3.6.2.4 Consolidation and Protection

The Contractor shall ensure that the concrete is properly consolidated, finished, protected, and cured.

3.6.3 Action Required

3.6.3.1 Placing

The placing foreman shall not permit placing to begin until he has verified that an adequate number of acceptable vibrators, which are in working order and have competent operators, are available. Placing shall not be continued if any pile is inadequately consolidated.

03 30 04 - 18

3.6.3.2 Air Content

Whenever a test result is outside the specification limits, the concrete shall not be delivered to the forms and an adjustment shall be made to the dosage of the air-entrainment admixture.

3.6.3.3 Slump

Whenever a test result is outside the specification limits, the concrete shall not be delivered to the forms and an adjustment should be made in the batch weights of water and fine aggregate. The adjustments are to be made so that the water-cement ratio does not exceed that specified in the submitted concrete mixture proportion. The adjustments shall be made at the concrete plant. All water shall be batched to the mixer at the plant.

Water shall not be added to the mix at the placing site.

3.6.3.4 Concrete Strength Testing

At least one set of test specimens shall be made, for compressive strength, on each different concrete mixture placed during the day for each 100 cubic yards or fraction thereof, of that concrete mixture placed each day.

Additional sets of test specimens shall be made, as directed by the Contracting Officer, when the mixture proportions are changed or when low strengths have been detected. A truly random (not haphazard) sampling plan shall be developed by the Contractor and approved by the Contracting Officer prior to the start of construction. The plan shall assure that sampling is done in a completely random and unbiased manner. A set of test specimens for concrete with a 28-day specified strength shall consist of at least three specimens, one to be tested at 7 days and two at 28 days. The samples for strength tests shall be taken in accordance with ASTM C 172.

Test specimens shall be molded and cured in accordance with ASTM C 31/C 31M and tested in accordance with ASTM C 39/C 39M. Results of all strength tests shall be reported immediately to the Contracting Officer. The strength of the concrete will be considered satisfactory so long as the average of three consecutive acceptance test results equal or exceed the specified compressive strength, f'c, and no individual acceptance test result falls below f'c by more than 500 psi.

3.6.3.5 Flowable Fill Strength Testing

At least one set of test specimens shall be made, for compressive strength, on each different flowable fill mixture placed during the day for each 75 cubic yards or fraction thereof, of that flowable fill mixture placed each day. Additional sets of test specimens shall be made, as directed by the Contracting Officer, when the mixture proportions are changed or when low strengths have been detected. A truly random (not haphazard) sampling plan shall be developed by the Contractor and approved by the Contracting Officer prior to the start of construction. The plan shall assure that sampling is done in a completely random and unbiased manner. A set of test specimens for flowable fill with a 28-day specified strength shall consist of at least four specimens, one to be tested at 5 days, one to be tested at 7 days and two at 28 days. The samples for strength tests shall be taken in accordance with ASTM D 5971-07. Test specimens shall be molded and cured in accordance with ASTM D 4832 and tested in accordance with ASTM D 4832. Results of all strength tests shall be reported immediately to the Contracting Officer. The strength of the flowable fill will be considered satisfactory so long as the average of three consecutive acceptance test results equal or exceed the specified compressive strength, 03 30 04 - 19 f'c, and no individual acceptance test result falls below f'c by more than 25 psi.

3.6.4 Reports

The results of all tests and inspections conducted at the project site shall be reported informally at the end of each shift and in writing weekly and shall be delivered within 3 days after the end of each weekly reporting period. See Section 01 45 00.00 10 QUALITY CONTROL.

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