Attachment 5 - 03 30 00 Cast In Place Concrete.pdf

SECTION 03 30 00 Page 1

SECTION TABLE OF CONTENTS

DIVISION 03 - CONCRETE

SECTION 03 30 00

CAST-IN-PLACE

CONCRETE

PART 1 GENERAL

1.1 REFERENCES

1.2 DEFINITIONS

1.3 SUBMITTALS

1.4 MODIFICATION OF REFERENCES

1.5 DELIVERY, STORAGE, AND HANDLING

1.6 QUALITY ASSURANCE

1.6.1 Design Data

1.6.1.1 Concrete Mix Design

1.6.2 Shop Drawings

1.6.2.1 Formwork

1.6.2.2 Reinforcing Steel

1.6.3 Control Submittals

1.6.3.1 Concrete Curing Plan

1.6.3.2 Pumping Concrete

1.6.3.3 Safety Data Sheets

1.6.4 Test Reports

1.6.4.1 Fly Ash and Pozzolan

1.6.4.2 Slag Cement

1.6.4.3 Aggregates

1.6.5 Quality Control Plan

1.6.5.1 Field Testing Technician and Testing Agency

1.6.6 Laboratory Qualifications for Concrete Qualification Testing

1.6.7 Laboratory Accreditation

1.7 ENVIRONMENTAL REQUIREMENTS

PART 2 PRODUCTS

2.1 Steel Forms

2.1.1 Formwork Accessories

2.2 CONCRETE MATERIALS

2.2.1 Cementitious Materials

2.2.1.1 Portland Cement

2.2.1.2 Fly Ash

2.2.1.3 Slag cement

2.2.1.4 Silica Fume

2.2.1.5 Other Supplementary Cementitious Materials

2.2.2 Water

2.2.3 Aggregate

2.2.3.1 Normal-Weight Aggregate

2.2.4 Admixtures

2.3 MISCELLANEOUS MATERIALS

2.3.1 Concrete Curing Materials

2.4 CONCRETE MIX DESIGN

2.4.1 Properties and Requirements

2.4.2 Durability

SECTION 03 30 00 Page 2

2.4.2.1 Alkali-Aggregate Reaction

2.4.2.2 Freezing and Thawing Resistance

2.4.3 Trial Mixtures

2.4.4 Ready-Mix Concrete

PART 3 EXECUTION

3.1 EXAMINATION

3.2 PREPARATION

3.2.1 General

3.2.2 Edge Forms and Screed Strips for Slabs

3.2.3 Reinforcement and Other Embedded Items

3.3 FORMS

3.3.1 Coating

3.3.2 Reshoring

3.3.3 Reuse

3.3.4 Forms for Standard Rough Form Finish

3.3.5 Forms for Standard Smooth Form Finish

3.3.6 Form Ties

3.3.7 Tolerances for Form Construction

3.3.8 Removal of Forms and Supports

3.3.9 Strength of Concrete Required for Removal of Formwork

3.4 BATCHING, MEASURING, MIXING, AND TRANSPORTING CONCRETE

3.4.1 Measuring

3.4.2 Mixing

3.4.3 Transporting

3.5 PLACING CONCRETE

3.5.1 Pumping

3.5.2 Cold Weather

3.5.3 Hot Weather

3.5.4 Bonding

3.6 WASTE MANAGEMENT

3.7 CURING AND PROTECTION

3.7.1 Requirements for Type III, High-Early-Strength Portland

Cement

3.7.2 Curing Periods

3.7.3 Curing Formed Surfaces

3.7.4 Temperature of Concrete During Curing

3.7.5 Protection from Mechanical Injury

3.7.6 Protection After Curing

3.8 FIELD QUALITY CONTROL

3.8.1 Sampling

3.8.2 Testing

3.8.2.1 Slump Tests

3.8.2.2 Temperature Tests

3.8.2.3 Compressive Strength Tests

3.8.2.4 Air Content

3.8.2.5 Unit Weight of Structural Concrete

3.8.2.6 Strength of Concrete Structure

3.8.2.7 Non-Conforming Materials

3.8.2.8 Testing Concrete Structure for Strength

3.9 REPAIR, REHABILITATION AND REMOVAL

3.9.1 Crack Repair

3.9.2 Repair of Weak Surfaces

3.9.3 Failure of Quality Assurance Test Results

-- End of Section Table of Contents --

SECTION 03 30 00 Page 3

SECTION 03 30 00 CAST-IN-PLACE CONCRETE

PART 1 GENERAL

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 CONCRETE INSTITUTE (ACI)

ACI 117 (2010; Errata 2011) Specifications for

Tolerances for Concrete Construction and

Materials and Commentary

ACI 121R (2008) Guide for Concrete Construction

Quality Systems in Conformance with ISO

ACI 301 (2016) Specifications for Structural

Concrete

ACI 304.2R (2017) Guide to Placing Concrete by

Pumping Methods

ACI 304R (2000; R 2009) Guide for Measuring, Mixing, Transporting, and Placing

ACI 305R (2010) Guide to Hot Weather Concreting

ACI 306R (2016) Guide to Cold Weather Concreting

ACI 308.1 (2011) Specification for Curing Concrete

ACI SP-2 (2007; Abstract: 10th Edition) ACI

Manual of Concrete Inspection

ACI SP-15 (2011) Field Reference Manual:

Standard Specifications for Structural

Concrete ACI 301-05 with Selected ACI

References

AMERICAN HARDBOARD ASSOCIATION (AHA)

AHA A135.4 (1995; R 2004) Basic Hardboard

ASTM INTERNATIONAL (ASTM)

ASTM A615/A615M (2020) Standard Specification for

Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement

SECTION 03 30 00 Page 4

ASTM A706/A706M (2016) Standard Specification for

Low-Alloy Steel Deformed and Plain

Bars for Concrete Reinforcement

ASTM A780/A780M (2020) Standard Practice for

Repair of Damaged and Uncoated

Areas of Hot-Dip Galvanized

Coatings

ASTM A996/A996M (2016) Standard Specification for

Rail-Steel and Axle-Steel Deformed

Bars for Concrete Reinforcement

ASTM C31/C31M (2019a) Standard Practice for Making and Curing Concrete Test Specimens in the Field

ASTM C33/C33M (2018) Standard Specification for

Concrete Aggregates

ASTM C39/C39M (2020) Standard Test Method for

Compressive Strength of

Cylindrical Concrete Specimens

ASTM C42/C42M (2020) Standard Test Method for

Obtaining and Testing Drilled Cores and

Sawed Beams of Concrete

ASTM C78/C78M (2018) Standard Test Method for

Flexural Strength of Concrete (Using

Simple Beam with Third-Point

Loading)

ASTM C94/C94M (2020) 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 (2020) Standard Specification for Portland

Cement

ASTM C172/C172M (2017) Standard Practice for Sampling

Freshly Mixed Concrete

ASTM C173/C173M (2016) Standard Test Method for Air

Content of Freshly Mixed Concrete by the

Volumetric Method

SECTION 03 30 00 Page 5

ASTM C231/C231M (2017a) 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 C311/C311M (2018) Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete

ASTM C330/C330M (2017a) Standard Specification for

Lightweight Aggregates for Structural

Concrete

ASTM C494/C494M (2019) Standard Specification for Chemical

Admixtures for Concrete

ASTM C567/C567M (2019) Determining Density of Structural

Lightweight Concrete

ASTM C595/C595M (2020) Standard Specification for Blended

Hydraulic Cements

ASTM C618 (2019) Standard Specification for Coal Fly

Ash and Raw or Calcined Natural Pozzolan for Use in Concrete

ASTM C803/C803M (2018) Standard Test Method for

Penetration Resistance of Hardened Concrete

ASTM C873/C873M (2015) Standard Test Method for

Compressive Strength of Concrete Cylinders

Cast in Place in Cylindrical Molds

ASTM C900 (2015) Standard Test Method for

Pullout Strength of Hardened

ASTM C989/C989M (2018a) Standard Specification for

Slag Cement for Use in Concrete and

Mortars

ASTM C1017/C1017M (2013; E 2015) Standard Specification for Chemical Admixtures for Use in

Producing Flowing Concrete

ASTM C1074 (2011) Standard Practice for

Estimating Concrete Strength by the

Maturity Method

ASTM C1077 (2017) Standard Practice for

Agencies Testing Concrete and

Concrete Aggregates for Use in

Construction and Criteria for Testing

Agency Evaluation

ASTM C1157/C1157M (2020) Standard Performance

Specification for Hydraulic Cement

SECTION 03 30 00 Page 6

ASTM C1240 (2020) Standard Specification for

Silica Fume Used in Cementitious

Mixtures

ASTM C1260 (2014) Standard Test Method for

Potential Alkali Reactivity of

Aggregates (Mortar-Bar Method)

ASTM C1293 (2008; R 2015) Standard Test Method for Determination of Length Change of

Concrete Due to Alkali-Silica Reaction

ASTM C1567 (2013) Standard Test Method for

Potential Alkali-Silica Reactivity of

Combinations of Cementitious

Materials and Aggregate (Accelerated

Mortar-Bar Method)

ASTM C1602/C1602M (2018) Standard Specification for

Mixing Water Used in Production of

Hydraulic Cement Concrete

ASTM C1778 (2016) Standard Guide for Reducing the Risk of Deleterious Alkali-

Aggregate Reaction in Concrete

ASTM D1751 (2004; E 2013; R 2013) Standard

ASTM D3042 (2017) Standard Test Method for

Insoluble Residue in Carbonate

Aggregates

ASTM D5759 (2012; R 2020) Characterization of

Coal Fly Ash and Clean Coal

Combustion Fly Ash for Potential Uses

ASTM E96/E96M (2016) Standard Test Methods for

Water Vapor Transmission of

Materials

ASTM E329 (2020) Standard Specification for

Agencies Engaged in Construction

Inspection, Testing, or Special

Inspection

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST)

NIST PS 1 (2009) DOC Voluntary Product

Standard PS 1-07, Structural Plywood

1.2 DEFINITIONS

a. "Cementitious material" as used herein must include all

Portland cement, pozzolan, fly ash, slag cement, and silica

SECTION 03 30 00 Page 7 fume.

b. "Exposed to public view" means situated so that it can be seen from eye level from a public location after completion of the building.

A public location is accessible to persons not responsible for operation or maintenance of the building.

c. "Chemical admixtures" are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes.

d. "Supplementary cementing materials" (SCM) include coal fly ash, silica fume, slag cement, natural or calcined pozzolans, and ultra-fine coal ash when used in such proportions to replace the portland cement that result in improvement to sustainability and durability and reduced cost.

e. "Design strength" (f'c) is the specified compressive strength of concrete at time(s) specified in this section to meet structural design criteria.

f. "Mass Concrete" is any concrete system that approaches a maximum temperature of 70 degrees C within the first 72 hours of placement.

In addition, it includes all concrete elements with a section thickness of

1 meter or more regardless of temperature.

g. "Mixture proportioning" is the process of designing concrete mixture proportions to enable it to meet the strength, service life and constructability requirements of the project while minimizing the initial and life-cycle cost.

h. "Mixture proportions" are the masses or volumes of individual ingredients used to make a unit measure (cubic meter or cubic yard) of concrete.

i. "Pozzolan" is a siliceous or siliceous and aluminous material, which in itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties.

j. "Workability (or consistence)" is the ability of a fresh (plastic) concrete mix to fill the form/mould properly with the desired work

(vibration) and without reducing the concrete's quality.

Workability depends on water content, chemical admixtures, aggregate (shape and size distribution), cementitious content and age (level of hydration).

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 information only. When used, a code following the "G" classification identifies the office that will review the submittal for the Government.

Submit the following in accordance with the Scope of Work:

SECTION 03 30 00 Page 8

SD-01 Pre-procurement Submittals

Concrete Curing Plan; G

SD-02 Not Used

SD-03 Product Data

Concrete Curing Materials; G

Admixtures; G

Pumping Concrete

SD-04 Design Data

Concrete Mix Design; G

SD-05 Test Reports

Concrete Mix Design; G

Fly Ash

Pozzolan Slag Cement

Aggregates

Tolerance Report

Compressive Strength Tests; G

Unit Weight of Structural

Concrete Chloride Ion

Concentration

Air

Content

Slump

Tests

Water

SD-06 Certificates

Silica Fume Manufacturer's Representative

Safety Data Sheets

Laboratory Accredation

SD-07 Manufacturer's Instructions

SECTION 03 30 00 Page 9

Curing Compound

1.4 MODIFICATION OF REFERENCES

Accomplish work in accordance with ACI publications except as modified herein. Consider the advisory or recommended provisions to be mandatory.

Interpret reference to the "Building Official," the "Structural Engineer," and the "Architect/Engineer" to mean the Contracting Officer.

1.5 DELIVERY, STORAGE, AND HANDLING

Follow ACI 301, ACI 304R and ASTM A934/A934M requirements and recommendations. Do not deliver concrete until forms and embedded items are in place and ready for concrete placement. Do not store concrete curing compounds or sealers with materials that have a high capacity to adsorb volatile organic compound (VOC) emissions. Do not store concrete curing compounds or sealers in occupied spaces.

1.6 QUALITY ASSURANCE

1.6.1 Design Data

1.6.1.1 Concrete Mix Design

Twenty-one (21) 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, supplementary cementitious materials, and admixtures; and applicable reference specifications. Submit mill test and all other test for cement, supplementary 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 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 placement.

1.6.3 Control Submittals

1.6.3.1 Concrete Curing Plan

Submit proposed materials, methods and duration for curing concrete elements in accordance with ACI 308.1.

SECTION 03 30 00 Page 10

1.6.3.2 Pumping Concrete

Submit proposed materials and methods for pumping concrete. Submittal must include mix designs, pumping equipment including type of pump and size and material for pipe, and maximum length and height concrete is to be pumped.

1.6.3.3 Safety Data Sheets

Submit Safety Data Sheets (SDS) for all materials that are regulated for hazardous health effects. SDS must be readily accessible during each work shift to employees when they are at the construction site.

1.6.4 Test Reports

1.6.4.1 Fly Ash and Pozzolan

Submit test results in accordance with ASTM C618 for fly ash and pozzolan.

Submit test results performed within 6 months of submittal date.

1.6.4.2 Slag Cement

Submit test results in accordance with ASTM C989/C989M for slag cement.

Submit test results performed within 6 months of submittal date.

1.6.4.3 Aggregates

Submit test results in accordance with ASTM C33/C33M, or ASTM

C330/C330M for lightweight aggregate, and ASTM C1293 or ASTM C1567 as required in the paragraph titled ALKALI-AGGREGATE REACTION.

1.6.5 Quality Control Plan

Develop and submit for approval a concrete quality control program in accordance with the guidelines of ACI 121R and as specified herein.

The plan must include approved laboratories. Provide direct oversight for the concrete qualification program inclusive of associated sampling and testing. All quality control reports must be provided to the

Contracting Officer, Quality Manager and Concrete Supplier. Maintain a copy of ACI SP-15 and CRSI 10MSP at project site.

1.6.5.1 Field Testing Technician and Testing Agency

1.6.6 Laboratory Qualifications for Concrete Qualification Testing

The concrete testing laboratory must have the necessary equipment and experience to accomplish required testing. The laboratory must meet the requirements of ASTM C1077 and be Cement and Concrete

Reference Laboratory (CCRL) inspected.

1.6.7 Laboratory Accreditation

Laboratory and testing facilities must be provided by and at the expense of the Contractor. The laboratories performing the tests must be accredited in accordance with ASTM C1077, including ASTM C78/C78M and ASTM C1260. The accreditation must be current and must include the

SECTION 03 30 00 Page 11 required test methods, as specified. Furthermore, the testing must comply with the following requirements:

a. Aggregate Testing and Mix Proportioning: Aggregate testing and mixture proportioning studies must be performed by an accredited laboratory and under the direction of a registered professional engineer in a U.S. state or territory competent in concrete materials who is competent in concrete materials and must sign all reports and designs.

b. Acceptance Testing: Furnish all materials, labor, and facilities required for molding, curing, testing, and protecting test specimens at the site and in the laboratory. Furnish and maintain boxes or other facilities suitable for storing and curing the specimens at the site while in the mold within the temperature range stipulated by ASTM C31/C31M.

c. Contractor Quality Control: All sampling and testing must be performed by an approved, onsite, independent, accredited laboratory.

1.7 ENVIRONMENTAL REQUIREMENTS

Provide space ventilation according to material manufacturer recommendations, at a minimum, during and following installation of concrete curing compound and sealer. Maintain one of the following ventilation conditions during the curing period or for

72 hours after installation:

a. Supply 100 percent outside air 24 hours a day.

b. Supply airflow at a rate of 6 air changes per hour, when outside temperatures are between 13 degrees C and 29 degrees C and humidity is between 30 percent and 60 percent.

c. Supply airflow at a rate of 1.5 air changes per hour, when outside air conditions are not within the range stipulated above.

PART 2 PRODUCTS

2.1 Steel Forms

Provide steel form surfaces that do not contain irregularities, or dents.

2.1.1 FORMWORK ACCESSORIES

1.6.7.1.1 Use commercially manufactured formwork accessories, including ties and hangers.

2.2 CONCRETE MATERIALS

2.2.1 Cementitious Materials

SECTION 03 30 00 Page 12

2.2.1.1 Portland Cement

a. Unless otherwise specified, provide cement that conforms to

ASTM C150/C150M Type I and meets low alkali content requirements.

b. Use one brand and type of cement for formed concrete having exposed-to-view finished surfaces.

c. Submit information along with evidence demonstrating compliance with referenced standards. Submittals must include types of cementitious materials, manufacturing locations, shipping locations, and certificates showing compliance.

d. Cementitious materials must be stored and kept dry and free from contaminants.

2.2.1.2 Fly Ash

a. ASTM C618, except that the maximum allowable loss on ignition must not exceed 3 percent.

b. 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.

2.2.1.3 Slag cement

ASTM C989/C989M, Grade 100. Slag content must be a minimum of 25 percent by weight of cementitious material.

2.2.1.4 Silica Fume

Silica fume must conform to ASTM C1240, including the optional limits on reactivity with cement alkalis. Silica fume may be furnished as a dry, densified material or as slurry. Proper mixing is essential to accomplish proper distribution of the silica fume and avoid agglomerated silica fume which can react with the alkali in the cement resulting in premature and extensive concrete damage. Supervision at the batch plant, finishing, and curing is essential. Provide at the

Contractor's expense the services of a manufacturer's technical representative, experienced in mixing, proportioning, placement procedures, and curing of concrete containing silica fume. This representative must be present on the project prior to and during at least the first 4 days of concrete production and placement using silica fume. A High Range Water Reducing admixture (HRWRA) must be used with silica fume.

2.2.1.5 Other Supplementary Cementitious Materials

Natural pozzolan must be raw or calcined and conform to ASTM C618, Class N, including the optional requirements for uniformity and effectiveness in controlling ASR and must have an ignition loss not

SECTION 03 30 00 Page 13 exceeding 3 percent.

Class N pozzolan for use in mitigating ASR must have a Calcium Oxide

(CaO) content of less than 13 percent and total equivalent alkali content less than 3 percent.

Ultra Fine Fly Ash (UFFA) and Ultra Fine Pozzolan (UFP) must conform to ASTM C618, Class F or N, and the following additional requirements:

a. The strength activity index at 28 days of age must be at least 95 percent of the control specimens.

b. The average particle size must not exceed 6 microns.

c. The sum of SiO2 + Al2O3 + Fe2O3 must be greater than 77 percent.

2.2.2 Water

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

b. Minimize the amount of water in the mix. Improve workability by adjusting the grading of the aggregate and using admixture rather than by adding water.

c. Water must be potable; free from injurious amounts of oils, acids, alkalis, salts, organic materials, or other substances deleterious to concrete.

d. Protect mixing water and ice from contamination during storage and delivery.

e. Submit test report showing water complies with ASTM C1602/C1602M.

2.2.3 Aggregate

2.2.3.1 Normal-Weight Aggregate

a. Aggregates must conform to ASTM C33/C33M.

b. Aggregates used in concrete must be obtained from the same sources and have the same size range as aggregates used in concrete represented by submitted field test records or used in trial mixtures.

c. Provide sand that is at least 50 percent acid insoluble based on ASTM D3042.

d. Store and handle aggregate in a manner that will avoid segregation and prevents contamination by other materials or other sizes of aggregates. Store aggregates in locations that will permit them to drain freely.

Do not use aggregates that contain frozen lumps.

e. Submit types, pit or quarry locations, producers' names, aggregate supplier statement of compliance with ASTM C33/C33M, and ASTM C1293 expansion data not more than 18 months old.

2.2.4 Admixtures

SECTION 03 30 00 Page 14

a. Chemical admixtures must conform to ASTM C494/C494M.

b. Air-entraining admixtures must conform to ASTM C260/C260M.

c. Chemical admixtures for use in producing flowing concrete must conform to ASTM C1017/C1017M.

d. Do not use calcium chloride admixtures.

e. Admixtures used in concrete must be the same as those used in the concrete represented by submitted field test records or used in trial mixtures.

f. Protect stored admixtures against contamination, evaporation, or damage.

g. To ensure uniform distribution of constituents, provide agitating equipment for admixtures used in the form of suspensions or unstable solutions. Protect liquid admixtures from freezing and from temperature changes that would adversely affect their characteristics.

h. Submit types, brand names, producers' names, manufacturer's technical data sheets, and certificates showing compliance with standards required herein.

2.3 MISCELLANEOUS MATERIALS

2.3.1 Concrete Curing Materials

Provide concrete curing material in accordance with ACI 301 Section 5 and

ACI 308.1 Section 2. Submit product data for concrete curing compounds.

Submit manufactures instructions for placement of curing compound.

2.4 CONCRETE MIX DESIGN

2.4.1 Properties and Requirements

a. Use materials and material combinations listed in this section and the contract documents.

b. Cementitious material content must be adequate for concrete to satisfy the specified requirements for strength, w/cm, durability, and finishability described in this section and the contract documents.

The minimum cementitious material content for concrete used in walls must meet the following requirements:

Nominal maximum size of aggregate, mm

Minimum cementitious material content, kg per cubic meter

25 310

19 320

9.5 360

SECTION 03 30 00 Page 15

c. Selected target slump must meet the requirements this section, the contract documents, and must not exceed 230 mm. Concrete must not show visible signs of segregation.

d. The target slump must be enforced for the duration of the project.

Determine the slump by ASTM C143/C143M. Slump tolerances must meet the requirements of ACI 117.

e. The nominal maximum size of coarse aggregate for a mixture must not exceed three-fourths of the minimum clear spacing between reinforcement, one-fifth of the narrowest dimension between sides of forms, or one-third of the thickness of slabs or toppings.

f. Concrete must be air entrained. The total air content must be in accordance with the requirements of the paragraph titled

DURABILITY.

g. Measure air content at the point of delivery in accordance with ASTM C173/C173M or ASTM C231/C231M.

h. Concrete properties and requirements for each portion of the structure are specified in the table below. Refer to the paragraph titled DURABILITY for more details on exposure categories and their requirements.

Minimum f'c MPa Miscellaneous Requirements

Columns and walls 28 at 28 days Nominal maximum aggregate size must be 25 mm

2.4.2 Durability

2.4.2.1 Alkali-Aggregate Reaction

Do not use any aggregate susceptible to alkali-carbonate reaction

(ACR). Use one of the three options below for qualifying concrete mixtures to reduce the potential of alkali-silica reaction (ASR):

a. For each aggregate used in concrete, the expansion result determined in accordance with ASTM C1293 must not exceed 0.04 percent at one year.

b. For each aggregate used in concrete, the expansion result of the aggregate and cementitious materials combination determined in accordance with ASTM C1567 must not exceed 0.10 percent at an age of 16 days.

c. Alkali content in concrete (LBA) must not exceed 2.4 kg per cubic meter for moderately reactive aggregate or 1.8 kg per cubic meter for highly reactive aggregate. Reactivity must be determined by testing in accordance with ASTM C1293 and categorized in accordance with ASTM

C1778. Alkali content is calculated as follows:

LBA = (cement content, kg per cubic meter) × (equivalent alkali content of portland cement in percent/100 percent)

SECTION 03 30 00 Page 16

2.4.3 Trial Mixtures

Trial mixtures must be in accordance to ACI 301.

2.4.4 Ready-Mix Concrete

Provide concrete that meets the requirements of ASTM C94/C94M.

Ready-mixed concrete manufacturer must provide duplicate delivery tickets with each load of concrete delivered. Provide delivery tickets with the following information in addition to that required by ASTM C94/C94M:

a. Type and brand cement

b. Cement and supplementary cementitious materials content in 43-kilogram bags per cubic meter of concrete

c. Maximum size of aggregate

d. Amount and brand name of admixtures

e. Total water content expressed by water cementitious material ratio

PART 3 EXECUTION

3.1 EXAMINATION

a. Do not begin installation until substrates have been properly constructed; verify that substrates are level.

b. If substrate preparation is the responsibility of another installer, notify Contracting Officer of unsatisfactory preparation before processing.

c. Check field dimensions before beginning installation. If dimensions vary too much from design dimensions for proper installation, notify

Contracting Officer and wait for instructions before beginning installation.

3.2 PREPARATION

Determine quantity of concrete needed and minimize the production of excess concrete. Designate locations or uses for potential excess concrete before the concrete is poured.

3.2.1 General

a. Surfaces against which concrete is to be placed must be free of debris, loose material, standing water, snow, ice, and other deleterious substances before start of concrete placing.

b. Remove standing water without washing over freshly deposited concrete. Divert flow of water through side drains provided for such purpose.

SECTION 03 30 00 Page 17

3.2.2 Edge Forms and Screed Strips for Slabs

a. Set edge forms or bulkheads and intermediate screed strips for slabs to obtain indicated elevations and contours in finished slab surface and must be strong enough to support vibrating bridge screeds or roller pipe screeds if nature of specified slab finish requires use of such equipment.

b. Align concrete surface to elevation of screed strips by use of strike-off templates or approved compacting-type screeds.

3.3 FORMS

a. Provide forms, shoring, and scaffolding for concrete placement.

Set forms mortar-tight and true to line and grade.

b. Inspect formwork and remove foreign material before concrete is placed.

c. Provide positive means of adjustment (such as wedges or jacks) of shores and struts. Do not make adjustments in formwork after concrete has reached initial setting. Brace formwork to resist lateral deflection and lateral instability.

d. Fasten form wedges in place after final adjustment of forms and before concrete placement.

e. Provide anchoring and bracing to control upward and lateral movement of formwork system.

f. Construct formwork for openings to facilitate removal and to produce opening dimensions as specified and within tolerances.

g. Provide runways for moving equipment. Support runways directly on formwork or structural members. Do not support runways on reinforcement. Loading applied by runways must not exceed capacity of formwork or structural members.

h. Clean surfaces of formwork and embedded materials of mortar, grout, and foreign materials before concrete placement.

3.3.1 Reshoring

a. Do not allow structural members to be loaded with combined dead and construction loads in excess of loads indicated in the accepted procedure.

b. Install and remove reshores or backshores in accordance with accepted procedure.

3.3.2 Forms for Standard Rough Form Finish

Provide formwork in accordance with ACI 301 Section 5 with a surface finish, SF-1.0, for formed surfaces that are to be concealed by other construction.

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3.3.3 Tolerances for Form Construction

a. Construct formwork so concrete surfaces conform to tolerances in ACI

117.

b. Position and secure sleeves, inserts, anchors, and other embedded items such that embedded items are positioned within ACI 117 tolerances.

c. To maintain specified elevation and thickness within tolerances, install formwork to compensate for deflection and anticipated settlement in formwork during concrete placement. Set formwork and intermediate screed strips for slabs to produce designated elevation, camber, and contour of finished surface before formwork removal. If specified finish requires use of vibrating screeds or roller pipe screeds, ensure that edge forms and screed strips are strong enough to support such equipment.

3.4 BATCHING, MEASURING, MIXING, AND TRANSPORTING CONCRETE

In accordance with ASTM C94/C94M, ACI 301, ACI 302.1R and ACI 304R, except as modified herein. Batching equipment must be such that the concrete ingredients are consistently measured within the following tolerances: 1 percent for cement and water, 2 percent for aggregate, and 3 percent for admixtures. Furnish mandatory batch ticket information for each load of ready mix concrete.

3.4.1 Measuring

Make measurements at intervals as specified in paragraphs SAMPLING and TESTING.

3.4.2 Mixing

a. Mix concrete in accordance with ASTM C94/C94M, ACI 301 and ACI 304R.

b. Machine mix concrete. Begin mixing within 30 minutes after the cement has been added to the aggregates. Place concrete within 90 minutes of either addition of mixing water to cement and aggregates or addition of cement to aggregates if the air temperature is less than 29 degrees

C.

c. Reduce mixing time and place concrete within 60 minutes if the air temperature is greater than 29 degrees C except as follows: if set retarding admixture is used and slump requirements can be met, limit for placing concrete may remain at 90 minutes. Additional water may be added, provided that both the specified maximum slump and submitted water-cementitious material ratio are not exceeded and the required concrete strength is still met. When additional water is added, an additional 30 revolutions of the mixer at mixing speed is required.

d. If the entrained air content falls below the specified limit, add a sufficient quantity of admixture to bring the entrained air content within the specified limits. Dissolve admixtures in the mixing water and mix in the drum to uniformly distribute the admixture throughout the batch. Do not reconstitute concrete that has begun to solidify.

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3.4.3 Transporting

Transport concrete from the mixer to the forms as rapidly as practicable. Prevent segregation or loss of ingredients. Clean transporting equipment thoroughly before each batch. Do not use aluminum pipe or chutes. Remove concrete which has segregated in transporting and dispose of as directed.

3.5 PLACING CONCRETE

Place concrete in accordance with ACI 301 Section 5.

3.6.1 Pumping

ACI 304R and ACI 304.2R. Pumping must not result in separation or loss of materials nor cause interruptions sufficient to permit loss of plasticity between successive increments. Loss of slump in pumping equipment must not exceed 50 mm at discharge/placement. Do not convey concrete through pipe made of aluminum or aluminum alloy. Avoid rapid changes in pipe sizes.

Limit maximum size of course aggregate to 33 percent of the diameter of the pipe. Limit maximum size of well-rounded aggregate to 40 percent of the pipe diameter. Take samples for testing at both the point of delivery to the pump and at the discharge end.

3.6.2 Cold Weather

Cold weather concrete must meet the requirements of ACI 301 unless otherwise specified. Do not allow concrete temperature to decrease below

10 degrees C. Obtain approval prior to placing concrete when the ambient temperature is below 4 degrees C or when concrete is likely to be subjected to freezing temperatures within 24 hours. Cover concrete and provide sufficient heat to maintain 10 degrees C minimum adjacent to both the formwork and the structure while curing. Limit the rate of cooling to

3 degrees C in any 1 hour and 10 degrees C per 24 hours after heat application.

3.6.3 Hot Weather

Hot weather concrete must meet the requirements of ACI 301 unless otherwise specified. Maintain required concrete temperature using

Figure 4.2 in

ACI 305R to prevent the evaporation rate from exceeding 1 kg per square meter of exposed concrete per hour. Cool ingredients before mixing or use other suitable means to control concrete temperature and prevent rapid drying of newly placed concrete. Shade the fresh concrete as soon as possible after placing. Start curing when the surface of the fresh concrete is sufficiently hard to permit curing without damage. Provide water hoses, pipes, spraying equipment, and water hauling equipment, where job site is remote to water source, to maintain a moist concrete surface throughout the curing period. Provide burlap cover or other suitable, permeable material with fog spray or continuous wetting of the concrete when weather conditions prevent the use of either liquid membrane curing compound or impervious sheets. For vertical surfaces, protect forms from direct sunlight and add water to top of structure once concrete is set.

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3.6.4 Bonding

Surfaces of set concrete at joints, must be roughened and cleaned of laitance, coatings, loose particles, and foreign matter. Roughen surfaces in a manner that exposes the aggregate uniformly and does not leave laitance, loosened particles of aggregate, nor damaged concrete at the surface.

Obtain bonding of fresh concrete that has set as follows:

a. At joints between footings and walls or columns, between walls or columns and the beams or slabs they support, and elsewhere unless otherwise specified; roughened and cleaned surface of set concrete must be dampened, but not saturated, immediately prior to placing of fresh concrete.

b. At joints in exposed-to-view work; at vertical joints in walls; at joints near midpoint of span in girders, beams, supported slabs, other structural members; in work designed to contain liquids; the roughened and cleaned surface of set concrete must be dampened but not saturated and covered with a cement grout coating.

c. Provide cement grout that consists of equal parts of portland cement and fine aggregate by weight with not more than 22.5 liters of water per sack of cement. Apply cement grout with a stiff broom or brush to a minimum thickness of 1.6 mm. Deposit fresh concrete before cement grout has attained its initial set.

3.6 WASTE MANAGEMENT

Remove all waste, debris, and scrap from site.

3.7 CURING AND PROTECTION

Curing and protection in accordance with ACI 301 Section 5, unless otherwise specified. Begin curing immediately following form removal.

Avoid damage to concrete from vibration created by blasting, pile driving, movement of equipment in the vicinity, disturbance of formwork or protruding reinforcement, and any other activity resulting in ground vibrations. Protect concrete from injurious action by sun, rain, flowing water, frost, mechanical injury, tire marks, and oil stains. Do not allow concrete to dry out from time of placement until the expiration of the specified curing period. Do not use membrane-forming compound on surfaces where appearance would be objectionable, on any surface to be painted, where coverings are to be bonded to the concrete, or on concrete to which other concrete is to be bonded. If forms are removed prior to the expiration of the curing period, provide another curing procedure specified herein for the remaining portion of the curing period. Provide moist curing for those areas receiving liquid chemical sealer, hardener, or epoxy coating. Allow curing compound/sealer installations to cure prior to the installation of materials that adsorb VOCs.

3.7.1 Requirements for Type III, High-Early-Strength Portland Cement

The curing periods are required to be not less than one-fourth of those specified for portland cement, but in no case less than 72 hours.

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3.7.2 Curing Periods

ACI 301 Section 5, except 10 days for retaining walls, concrete or chimneys. Begin curing immediately after placement. Protect concrete from premature drying, excessively hot temperatures, and mechanical injury;

and maintain minimal moisture loss at a relatively constant temperature for the period necessary for hydration of the cement and hardening of the concrete. The materials and methods of curing are subject to approval by the Contracting Officer.

3.7.3 Curing Formed Surfaces

Accomplish curing of formed surfaces, including undersurfaces of girders, beams, supported slabs, and other similar surfaces by moist curing with forms in place for full curing period or until forms are removed. If forms are removed before end of curing period, accomplish final curing of formed surfaces by any of the curing methods specified above, as applicable.

3.7.4 Temperature of Concrete During Curing

When temperature of atmosphere is 5 degrees C and below, maintain temperature of concrete at not less than 13 degrees C throughout concrete curing period or 7 degrees C when the curing period is measured by maturity. When necessary, make arrangements before start of concrete placing for heating, covering, insulation, or housing as required to maintain specified temperature and moisture conditions for concrete during curing period.

When the temperature of atmosphere is 27 degrees C and above or during other climatic conditions which cause too rapid drying of concrete, make arrangements before start of concrete placing for installation of wind breaks, of shading, and for fog spraying, wet sprinkling, or moisture-retaining covering of light color as required to protect concrete during curing period.

Changes in temperature of concrete must be uniform and not exceed 3 degrees C in any 1 hour nor 27 degrees C in any 24-hour period.

3.7.5 Protection from Mechanical Injury

During curing period, protect concrete from damaging mechanical disturbances, particularly load stresses, heavy shock, and excessive vibration and from damage caused by rain or running water.

3.7.6 Protection After Curing

Protect finished concrete surfaces from damage by construction operations.

3.8 FIELD QUALITY CONTROL

3.8.1 Sampling

ASTM C172/C172M. Collect samples of fresh concrete to perform tests specified. ASTM C31/C31M for making test specimens.

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3.8.2 Testing

3.8.2.1 Slump Tests

ASTM C143/C143M. Take concrete samples during concrete placement/discharge.

The maximum slump may be increased as specified with the addition of an approved admixture provided that the water-cementitious material ratio is not exceeded. Perform tests at commencement of concrete placement, when test cylinders are made, and for each batch (minimum) or every 16 cubic meters (maximum) of concrete.

3.8.2.2 Temperature Tests

Test the concrete delivered and the concrete in the forms. Perform tests in hot or cold weather conditions (below 10 degrees C and above 27 degrees C) for each batch (minimum) or every 16 cubic meters (maximum) of concrete, until the specified temperature is obtained, and whenever test cylinders and slump tests are made.

3.8.2.3 Compressive Strength Tests

ASTM C39/C39M. Make eight 150 mm by 300 mm test cylinders for each set of tests in accordance with ASTM C31/C31M, ASTM C172/C172M and applicable requirements of ACI 305R and ACI 306R. Take precautions to prevent evaporation and loss of water from the specimen. Test two cylinders at 7 days, two cylinders at 28 days, two cylinders at 56 days, and hold two cylinder in reserve. Take samples for strength tests of each concrete placed each day not less than once a day, nor less than once for each 75 cubic meters of concrete for the first 380 cubic meters, then every 380 cubic meters thereafter, nor less than once for each 500 square meters of surface area for slabs or walls. For the entire project, take no less than five sets of samples and perform strength tests for each mix design of concrete placed. Each strength test result must be the average of two cylinders from the same concrete sample tested at 28 days. Concrete compressive tests must meet the requirements of this section, the Contract

Document, and ACI 301. Retest locations represented by erratic core strengths. Where retest does not meet concrete compressive strength requirements submit a mitigation or remediation plan for review and approval by the contracting officer. Repair core holes with nonshrink grout. Match color and finish of adjacent concrete.

3.8.2.4 Air Content

ASTM C173/C173M or ASTM C231/C231M for normal weight concrete and

ASTM C173/C173M for lightweight concrete. Test air-entrained concrete for air content at the same frequency as specified for slump tests.

3.8.2.5 Unit Weight of Structural Concrete

ASTM C567/C567M and ASTM C138/C138M. Determine unit weight of lightweight and normal weight concrete. Perform test for every 15 cubic meters maximum.

3.8.2.6 Strength of Concrete Structure

The strength of the concrete structure will be considered to be deficient if any of the following conditions are identified:

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a. Failure to meet compressive strength tests as evaluated.

b. Concrete which differs from required dimensions or location in such a manner as to reduce strength.

c. Concrete curing and protection of concrete against extremes of temperature during curing, not conforming to requirements specified.

d. Concrete subjected to damaging mechanical disturbances, particularly load stresses, heavy shock, and excessive vibration.

e. Poor workmanship likely to result in deficient strength.

Where the strength of the concrete structure is considered deficient submit a mitigation or remediation plan for review and approval by the contracting officer.

3.8.2.7 Non-Conforming Materials

Factors that indicate that there are non-conforming materials include

(but not limited to) excessive compressive strength, inadequate compressive strength, excessive slump, excessive voids and honeycombing, concrete delivery records that indicate excessive time between mixing and placement, or excessive water was added to the mixture during delivery and placement. Any of these indicators alone are sufficient reason for the Contracting Officer to request additional sampling and testing.

Investigations into non-conforming materials must be conducted at the

Contractor's expense. The Contractor must be responsible for the investigation and must make written recommendations to adequately mitigate or remediate the non-conforming material. The Contracting

Officer may accept, accept with reduced payment, require mitigation, or require removal and replacement of non-conforming material at no additional cost to the Government.

3.8.2.8 Testing Concrete Structure for Strength

When there is evidence that strength of concrete structure in place does not meet specification requirements or there are non-conforming materials, make cores drilled from hardened concrete for compressive strength determination in accordance with ASTM C42/C42M, and as follows:

a. Take at least three representative cores from each member or area of concrete-in-place that is considered potentially deficient.

Location of cores will be determined by the Contracting Officer.

b. Test cores after moisture conditioning in accordance with ASTM

C42/C42M if concrete they represent is more than superficially wet under service.

c. Air dry cores, (16 to 27 degrees C with relative humidity less than

60 percent) for 7 days before test and test dry if concrete they represent is dry under service conditions.

Strength of cores from each member or area are considered satisfactory if their

SECTION 03 30 00 Page 24 average is equal to or greater than 85 percent of the 28-day design compressive strength of the class of concrete.

Correct concrete work that is found inadequate by core tests in a manner approved by the Contracting Officer.

3.9 REPAIR, REHABILITATION AND REMOVAL

Before the Contracting Officer accepts the structure the Contractor must inspect the structure for cracks, damage and substandard concrete placements that may adversely affect the service life of the structure. A report documenting these defects must be prepared which includes recommendations for repair, removal or remediation must be submitted to the Contracting Officer for approval before any corrective work is accomplished.

3.9.1 Crack Repair

Prior to final acceptance, all cracks in excess of 0.50 mm wide must be documented and repaired. The proposed method and materials to repair the cracks must be submitted to the Contracting Officer for approval. The proposal must address the amount of movement expected in the crack due to temperature changes and loading.

3.9.2 Repair of Weak Surfaces

Weak surfaces are defined as mortar-rich, rain-damaged, uncured, or containing exposed voids or deleterious materials. Concrete surfaces with weak surfaces less than 6 mm thick must be diamond ground to remove the weak surface. Surfaces containing weak surfaces greater than 6 mm thick must be removed and replaced or mitigated in a manner acceptable to the

Contracting Officer.

3.9.3 Failure of Quality Assurance Test Results

Proposed mitigation efforts by the Contractor must be approved by the

Contracting Officer prior to proceeding.

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