32 13 11.pdf

Tinker AFB, OK TAFB Technical Specifications 2019

April 2019 Page 1 Section 32 13 11

SECTION 32 13 11

AIRFIELD PAVEMENT, PORTLAND CEMENT CONCRETE

PART 1 GENERAL

This section covers the installation and construction of concrete (rigid) pavement designated as Airfield Paving. Where the requirements of this section conflict with the requirements of another section or the approved plans the most restrictive requirement shall apply.

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by basic designation only. Unless specifically noted, the current edition of the reference will be used. The current edition is the edition in effect on the date of the RFP.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION

OFFICIALS (AASHTO)

AASHTO M 182 Standard Specification for Burlap Cloth Made from

Jute or Kenaf and Cotton Mats

AMERICAN CONCRETE INSTITUTE (ACI)

ACI 211.1 Standard Practice for Selecting Proportions for

Normal, Heavyweight and Mass Concrete

ACI 214R Evaluation of Strength Test Results of Concrete

ACI 305R Guide to Hot Weather Concreting

ACI 306R Guide to Cold weather Concreting

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM C 42 Standard Test Method for Obtaining and Testing

Drilled Cores and Sawed Beams of Concrete

ASTM C 88 Standard Test Method for Soundness of Aggregates by use of Sodium Sulfate or Magnesium Sulfate.

ASTM C 94 Standard Specification for Ready Mixed Concrete

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ASTM C 117 Standard Test Method for Materials Finer Than 75-x03BC;m Sieve in Mineral Aggregate by Washing

ASTM C 123 Standard Test Method for Lightweight Particles in

Aggregates

ASTM C 142 Standard Test Method for Clay Lumps and Friable

Particles in Aggregates

ASTM C 150 Standard Specification for Portland Cement

ASTM C 174 Standard Test Method for Measuring Thickness of

Concrete Elements Using Drilled Concrete Cores

ASTM C 295 Standard Guide for Petrographic Examination of

Aggregates for Concrete

ASTM C 666 Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing

ASTM C 1077 Standard Practice for Laboratories Testing

Concrete and Concrete Aggregates for Use in Construction and Criteria for Laboratory Evaluation

ASTM C 1157 Standard Performance Specification for Hydraulic

Cement

ASTM C 1260 Standard Test Method for Potential Alkali

Reactivity of Aggregates (Mortar Bar Method)

ASTM C 2995 Standard Practice for Estimating Application Rate of Bituminous Distributors

ASTM D 4791 Flat Particles, Elongated Particles, or Flat and

Elongated Particles in Coarse Aggregate

ASTM E 1274 Standard Test Method for Measuring Pavement Roughness Using a Profilograph

NATIONAL READY MIXED CONCRETE ASSOCIATION (NRMCA)

NRMCA QC MANUAL Section 3; Plant Certification Checklist

UNITED STATES ARMY CORPS OF ENGINEERS (USACE)

COE CRD-C 130 Standard Recommended Practice for

Estimating Scratch Hardness of Coarse Aggregate Particles

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COE CRD-C 521 Standard Test Method for Frequency and Amplitude of Vibrators for Concrete

1.2 SUBMITTALS

Government approval of all materials, designs, procedures, and equipment is required prior to use. The following are in addition to the submittals required by other sections and are to be submitted in accordance with Section 01 33 00; SUBMITTAL

PROCEDURES.

1.2.1 SD-01 Preconstruction

1.2.1.1 Work Plan.

a. A detailed description of the placing and protection methods proposed prior to construction of the test section.

b. A detailed plan of the proposed paving pattern showing all planned joints. No deviation from the jointing pattern shown on the drawings shall be made without written approval of the CO.

1.2.1.2 Data on the curing media and methods to be used.

1.2.1.3 Quality Control Plan

1.2.2 SD-03 Product Data

1.2.2.1 Batch Plant: Manufacturers literature on the plant to be used for batching concrete showing plant specifications and capacities and verifying that the plant meets or exceeds the requirements of the contract specifications.

1.2.2.2 Transport Equipment: Manufacturers literature on the

equipment to be used for transporting concrete showing equipment specifications and capacities and verifying that the equipment meets or exceeds the requirements of the contract specifications.

1.2.2.3 Placing Equipment: Manufacturers literature on the

equipment to be used for placing, consolidating, and finishing concrete showing equipment specifications and capacities and verifying that the equipment meets or exceeds the requirements of the contract specifications.

1.2.2.4 Profilograph Equipment: Manufacturers literature on the equipment to be used for profilograph testing of the concrete showing equipment specifications and verifying that the equipment meets or exceeds the requirements of the contract specifications.

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1.2.3 SD-05 Design Data

1.2.3.1 Concrete Mix Design: The contractor shall submit to the CO a mix design for each strength series of concrete specified. The submittal shall include a report from a qualified commercial laboratory showing the material sources, material proportions, admix quantities, and tests results. The tests results shall include slump, air content, unit weight, temperature, and strength, both compressive and flexural, at seven days and at 28 days. The report shall be sealed by an engineer licensed in the state of Oklahoma, certifying that the report is true and accurate and that the materials meet project specifications and are from the same sources that will be used for the project. The report shall be submitted to the CO no later than 30 days prior to the commencement of paving.

1.2.4 SD-07 Certificates

1.2.4.1 Batch Plant: A certified copy of the NRMCA QC Manual, Section 3; Concrete Plant Certification Checklist shall be submitted to the CO prior to uniformity testing. The date of inspection and certification shall be within the last 12 months.

1.2.4.2 Batch Plant: A copy of the documentation from the

calibrating company(s), certifying that all measuring and weighing devices are within tolerances shall be submitted to the CO prior to uniformity testing. The date of inspection and certification shall be within the last six months.

1.2.4.3 Personnel: American Concrete Institute (ACI) certifications for Contractor Quality Control Staff shall be submitted to the CO no later than 10 working days prior to the start of paving operations.

1.2.4.4 Personnel: Qualifications and resumes for the Licensed

Surveyor, the Petrographer, each Concrete Batch Plant Operator, each Paving Machine Operator, and each Profilograph Operator shall be submitted to the CO no later than 10 working days prior to the start of paving operations.

1.2.4.5 Laboratory: Certification of the accreditation of the commercial laboratory by an independent evaluation authority, indicating conformance to ASTM C 1077, including all applicable test procedures and personnel qualifications, shall be submitted to the CO with the submittal specified in paragraph 1.2.3 of this section.

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1.3 ACCEPTABILITY OF MATERIALS and WORKMANSHIP

1.3.1 Materials

1.3.1.1 The materials shall be accepted on the basis of tests made by the Contractor's approved commercial laboratory. The Government may, at its discretion, make check tests to validate the Contractor's testing. Validation tests shall be performed on duplicate samples.

1.3.1.2 If the results of the Government’s tests and Contractor’s tests vary by less than 2.0 percent, the results of the Contractor's tests will be considered valid.

1.3.1.3 If the results of the Government’s tests and Contractor’s tests vary by 2.0 percent or more, but less than 4.0 percent, the average of the two will be considered the value to be used. The Government’s and Contractor’s quality control personnel shall inspect and evaluate all equipment and procedures to identify and correct the reason for the discrepancy.

1.3.1.4 Operations shall cease immediately if the tests results vary by 4.0 percent or more. The Government’s and the Contractor’s quality control personnel shall inspect all equipment and shall evaluate each sampling and testing procedure. Operations may continue when the cause for the discrepancy has been identified and corrected and the variance of test results on duplicate samples is within tolerance.

1.3.2 Pavement

Concrete pavement shall be accepted based on strength tests and conformance to the lines, grade, smoothness, and thickness as specified.

1.3.2.1 Strength Test

Strength test shall be performed and reported in accordance with Section 03 00 01; CONCRETE CONSTRUCTION.

1.3.2.2 Plan and Grade

The finished pavement shall conform to the dimensions, elevations, and lines as shown on the approved plans or in the project specifications. The contractor shall verify all dimensions, elevations, and lines no earlier than 24 hours and no later than five working days after each placement.

All measurements are to be taken in the presence of the representative of the CO. A clear and legible copy of the results, signed by the contractor and the representative of

April 2019 Page 6 Section 32 13 11 the CO witnessing the measurements, will be submitted to the CO no later than three working days after the completion of the verification measurements.

a. Conformance

The finished surface of the pavement shall be tested by the Contractor by running lines of levels at intervals corresponding to every longitudinal and transverse joint to determine the trueness of the line and the elevation at each joint intersection. The results of this survey shall be recorded and a copy furnished to the CO at the end of each day’s testing. The finished surfaces of all pavements, including runway, taxiway, and apron pavements, shall not vary more than one half of an inch horizontally from the plan grade line nor more than one half of an inch above or below the elevation specified.

1.3.2.3 Surface Smoothness

a. The finished surfaces of airfield pavements shall have no abrupt changes in elevation. The finished surfaces of new pavement and the finished surface of existing pavement shall coincide at their juncture.

b. The profilograph method shall be used for all longitudinal testing, except for paving lanes less than 200 feet in length. The straightedge method shall be used for transverse testing, for longitudinal testing where the length of each pavement lane is less than 200 feet, and at the ends of the paving limits of the project.

1.3.2.4 Straightedge Testing

a. Tolerance

(1) All pavements shall be within the limits specified in Table

1 when checked with an approved straightedge.

(2) The straightedge shall be 12 feet in length.

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TABLE 1

STRAIGHTEDGE SURFACE SMOOTHNESS

Location Direction Limits (inches)

Runways and Taxiways

Longitudinal 1/8

Transverse 1/4

Calibration Hardstands and Compass Swing

Bases

Longitudinal 1/8

Transverse 1/8

All Other Pavements and Paved Areas

Longitudinal 1/4

Transverse 1/4

b. Method

(1) After the concrete has hardened sufficiently to permit walking thereon, but not later than 48 hours after placement, test the entire surface of the pavement in each lot in such a manner as to reveal all surface irregularities exceeding the tolerances specified above.

If any pavement areas are ground, these areas shall be retested immediately after diamond grinding. The entire area of the pavement shall be tested in both a longitudinal and a transverse direction on parallel lines. The transverse lines shall be 15 feet or less apart, as directed. The longitudinal lines shall be at the centerline of each paving lane shown on the drawings, regardless of whether the Contractor is allowed to pave two lanes at a time, and at the 1/8th point in from each side of the lane. Other areas having obvious deviations shall also be tested. Longitudinal testing lines shall be continuous across all joints. Transverse testing lines for pilot lanes shall be carried to construction joint lines and for fill-in lanes shall be carried 24 inches across construction joints, and the readings in this area applied to the fill-in lane. Straightedge testing of the longitudinal edges of slip formed pilot lanes shall also be performed before paving fill-in lanes as specified below.

(2) The straightedge shall be held in contact with the surface and moved ahead one-half the length of the straightedge for

April 2019 Page 8 Section 32 13 11 each successive measurement. The amount of surface irregularity shall be determined by placing the freestanding (unleveled) straightedge on the pavement surface and measuring the maximum gap between the straightedge and the pavement surface. Measurements shall be taken along the entire length of the straightedge at one foot intervals.

c. Detailed notes shall be kept of the results of the testing and a copy, signed by the contractor QC manager and the representative of the CO, shall be turned in to the CO after each day’s testing.

1.3.2.5 Profilograph Testing

a. Tolerance

All pavements shall have a Profile Index not greater than specified in Table 2 when tested with an approved California-type profilograph. If the extent of the pavement is less than 200 feet in either direction, that direction shall be checked by the straightedge method and shall meet the requirements of Table 1.

TABLE 2

PROFILOGRAPH SURFACE SMOOTHNESS

Location Direction Maximum Index (inches per mile)

Runways and Taxiways

Longitudinal 7

Transverse Use Straightedge

Calibration Hardstands and Compass Swing

Bases

Longitudinal Use Straightedge

Transverse Use Straightedge

All Other Pavements and Paved Areas

Longitudinal 9

Transverse 9

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b. Method

Profilograph testing shall be performed using approved equipment and in accordance with the procedures specified in ASTM E-1274. The equipment shall use electronic recording and automatic computerized reduction of data to indicate “must-grind” bumps and the Profile Index for each one tenth mile segment of pavement. Grade breaks on aprons shall be accommodated by breaking the profile segment into short sections and repositioning the blanking band on each section. The blanking band shall be two tenths of an inch wide and the bump template shall span one inch with an offset of four tenths of an inch. The profilograph testing of the last 30 feet of a paving lane in the longitudinal direction from each day’s paving operation shall be counted on the following day’s continuation lane. The profile index shall be computed for each pass of the profilograph (3 per lane) in each one tenth mile segment. The profile index for each segment shall be the average of the profile indices for each pass in each segment. Profilographs of unequal lengths shall be scaled and proportioned to an equivalent one tenth mile.

c. A copy of the reduced tapes shall be furnished to the CO at the end of each day’s testing.

1.3.2.6. Bumps ("Must Grind" Areas).

Any bumps ("must grind" areas) shown on the profilograph trace which exceed 4/10 inch in height shall be reduced by diamond grinding until they do not exceed 3/10 inch when retested. Such grinding shall be tapered in all directions to provide smooth transitions to areas not requiring grinding. The following will not be permitted: (1) skin patching for correcting low areas, (2) planeing or milling for correcting high areas. At the Contractor's option, pavement areas, including ground areas, may be rechecked with the profilograph in order to record a lower Profile Index.

1.3.2.7 Where project plans require deviation from a plane surface

(crowns, drainage inlets, etc.) the surface shall be finished in accordance with the approved plans.

1.3.2.8 Edge Slump and Joint Face Deformation

a. Edge Slump

(1). When slip form paving is used, not more than 15 percent of the total free edge of each day’s placement shall have an edge slump of more than one fourth (1/4)

April 2019 Page 10 Section 32 13 11 of an inch and none of the free edge shall have an edge slump of more than three eights (3/8) of an inch.

(2). The area affected by the downward movement of the concrete along the pavement edge shall not extend more than eighteen (18) inches back from the edge.

(3). The total free edge of the pavement shall be considered to be the cumulative total linear measurement of pavement edge constructed non-adjacent to any existing pavement (i.e., 100 feet of pilot lane will have 200 feet of free edge, 100 feet of fill-in lane will have no free edge, etc.).

(4). Edge slump shall be determined by placing a straightedge transverse to the direction of paving with one end of the straightedge placed at the pavement edge. Measurements shall be taken at intervals of five (5) feet commencing at the header where paving started. When no deficiencies are found, the measurement interval may be increased by the CO to a maximum of fifteen (15) feet. The interval shall return to five (5) feet any time deficiencies are found. The straightedge shall be a minimum of four (4) feet in length.

b. Joint Face Deformation

In addition to the edge slump limits specified, the surface of the vertical joint face shall not exceed the following:

(1) The offset from a straight edge applied longitudinally to the pavement surface shall not be more than one eighth of an inch.

(2) The offset from a straightedge applied longitudinally to the vertical face of the pavement shall not be more than one fourth of an inch.

(3) The offset from a straightedge applied vertically (top to bottom) to the vertical face shall not be more than three eights of an inch.

(4) There shall be no abrupt offset in any direction of more than one eighth of an inch.

(5) The offset of the vertical face from true vertical shall not be more than eight percent (1:12).

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(6) Method

Joint Face Deformation shall be determined by placing a straightedge against the face in the direction specified. Measurements shall be taken at intervals of five (5) feet commencing at the header where paving started. When no deficiencies are found, the measurement interval may be increased by the CO to a maximum of fifteen (15) feet. The interval shall return to five (5) feet any time deficiencies are found. The straightedge shall be a minimum of four (4) feet in length.

c. Edge Smoothness

The longitudinal surface smoothness of the joint shall be checked on a continuous line one inch back from the joint face. The testing shall be in accordance with and meet the tolerances of paragraph 1.2.3.4.

1.3.2.9 Edge Spalls

a. No more than 15 percent of each slab’s edge shall be spalled.

b. Slabs with spalls exceeding 15 percent, regardless of spall size, shall be removed and replaced.

1.3.2.10 Cracks

a. Slabs with cracks deeper than 25 percent of the thickness shall be removed and replaced.

b. Slabs with cracks with a depth less than or equal to 25 percent of the thickness shall be repaired by an approved epoxy injection system.

1.3.2.11 Thickness

a. The thickness of the concrete pavement shall be checked using cores evaluated according to the guidelines specified in ASTM C-174.

b. The cores shall be either four inch or six inch in diameter. Cores shall be obtained in accordance with ASTM C-42.

c. Eight cores shall be drilled at even increments in each lane of each day’s placement. If the length of the lane is less than 1000 feet, then the number of cores may be decreased by one for every 250 feet decrease in length.

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d. The thickness of the day’s pavement shall be the average thickness of the cores taken.

e. The pavement shall be acceptable if the average thickness is greater than 90 percent of the specified thickness and no single core is less than 85 percent of the specified thickness.

f. If two or more of the cores have a thickness less than 80 percent of the specified thickness, then the entire placement shall be rejected.

g. If one core has a thickness less than 80 percent of the specified thickness, then cores shall be taken from adjacent slabs until the limits of the non-conforming concrete are known. The limits shall be slabs where the thickness is greater than or equal to 90 percent of the specified thickness. All concrete within the limits shall be rejected.

h. All concrete pavements with a measured thickness less than

80 percent of the specified thickness shall be removed and replaced at no expense to the government.

1.4 AGGREGATE DURABILITY

1.4.1 Aggregate shall have a satisfactory freeze / thaw service record of at least 5 years in 3 concrete paving projects.

1.4.2 The service record shall include a condition record of the existing pavement and a review of the concrete constituents, including coarse and fine aggregate, cement and mineral admixtures.

1.4.3 The aggregates shall be from the same sources proposed for use on this project.

1.4.4 The review shall consider all aggregate tests reports, cement mill certification data, mineral admixture mill certification data and the cf and w/c of the concrete mixture.

1.4.5 Aggregate shall have a minimum durability factor of 50 when tested in accordance with ASTM C666, Procedure A.

1.4.6 Coarse and fine shall be evaluated and tested in accordance with ASTM C88;

1.4.6.1 The loss shall be a maximum of 18% when tested with

magnesium sulfate, April 2019 Page 13 Section 32 13 11

1.4.6.2 The loss shall be a maximum of 12% when tested with sodium sulfate.

PART 2 PRODUCTS

2.1 CONCRETE

Concrete and concrete related materials shall conform to the requirements of Section 03 00 01; CONCRETE CONSTRUCTION and its associated sections with the following additions.

2.1.1 All concrete for use on airfield paving shall be Class AP.

2.1.2 Unless specified otherwise on the approved plans, the

minimum flexural strength of concrete for airfield paving shall be 500 pounds per square inch (500 psi) at seven days of age and 650 pounds per square inch (650 psi) at 28 days of age.

2.1.3 All concrete mix designs shall meet the requirements of

Option R of ASTM C 1157 when tested in accordance with ASTM C 1260. Exception: The limit for 56 day expansion shall be deleted and replaced with 0.08% at 28 days.

2.1.4 Concrete for airfield paving shall contain a minimum of 517 pounds of cement per cubic yard of concrete.

2.1.5 All concrete for airfield paving shall be air entrained.

2.1.6 All joint sealing materials and systems for airfield paving shall be jet fuel resistant.

2.1.7 All set accelerating admixtures for use in airfield paving shall be classified as non-chloride.

2.2 CEMENT

2.2.1 Cement for airfield shall meet the requirements of ASTM C

150 Type I.

2.2.2 Cement for airfield pavement classified as “High Early” shall meet the requirements of ASTM C 150 Type III.

2.2.1 Cement for use in concrete for airfield paving shall be classified as “low-alkali” and shall conform to the limits of ASTM C 150, Table 2 for Equivalent Alkalis.

2.2.2 All cementitious material shall be furnished in bulk. The temperature of the cementitious material shall not exceed 150 degrees F. at the time of delivery.

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2.2.3 Cement that has been stored at the site for sixty (60) or more days shall be used prior to cement stored a lesser time.

2.3 COARSE AGGREGATE

2.3.1 All coarse aggregate for use in airfield paving shall be washed.

2.3.2 Coarse aggregate for use in paving compass calibration

hardstands shall be free of materials having undesirable magnetic properties, including magnetite, high iron content, and pyrite.

2.3.2 Particles of the coarse aggregate shall be generally

spherical or cubical in shape. The quantity of flat and elongated particles in any size group shall not exceed 20 percent as determined by the procedures specified in ASTM D-4791. A flat particle is defined as one having a ratio of width to thickness greater than three; an elongated particle is one having a ratio of length to width greater than three.

2.3.3 All coarse aggregate for Airfield Paving shall meet the deleterious material requirements of Table 3.

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TABLE 3

LIMITS OF DELETERIOUS MATERIALS IN COARSE AGGREGATES

Material Test Limits (Percent by Mass)

Airfield Non Airfield

Material Finer Than

0.075 mm (#200 sieve) ASTM C 117 0.5 1.0

Lightweight Particles ASTM C 123 0.2 1.0

Clay Lumps and Friable Particles ASTM C 142 0.2 2.0

Clay Limestone ASTM C 295 0.5

Claystone, Mudstone, and Siltstone ASTM C 295 0.1

Shale ASTM C 295 0.2

Shaly and Argillaceous Limestone

ASTM C 295 0.2

Chert and Cherty Stone (SSD sg < 2.4)

ASTM C 123

ASTM C 295 0.5

Other Soft Particles COE CRD-C 130 1.0 2.0

Total of All Deleterious Materials Exclusive of Material Finer Than 0.075 mm

2.0 5.0

2.4 FINE AGGREGATE

2.4.1 All fine aggregate for use in airfield paving shall be

natural sand.

2.4.2 Fine aggregate for use in paving compass calibration

hardstands shall be free of materials having undesirable magnetic properties, including magnetite, high iron content, and pyrite.

2.4.3 All fine aggregate for Airfield Paving shall meet the

deleterious material requirements of Table 4.

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TABLE 4

LIMITS OF DELETERIOUS MATERIALS IN FINE AGGREGATES

Material Test Limits

(Percent by Mass)

Material Finer Than

0.075 mm (#200 sieve) ASTM C 117 3.0

Lightweight Particles ASTM C 123 0.5

Clay Lumps and Friable Particles ASTM C 142 1.0

Total Deleterious 3.0

2.5 EQUIPMENT

2.5.1 General

2.5.1.1 The Contracting Officer shall be given access at all times to all parts of the plant and equipment for checking the adequacy of the equipment in use; the operation of the plant, verifying weights, proportions, temperature, mixing time, and character of the materials.

2.5.1.2 The batch plant and all equipment involved in the mixing, hauling, and placing concrete may be inspected by the Contracting Officer.

2.5.1.3 If any of the above mentioned equipment does not meet the manufacturer's specifications, this equipment will not be used until brought into compliance.

2.5.2 Batch Plant

2.5.2.1 The batch plant shall conform to the requirements of ASTM C-94.

2.5.2.2 The batch plant shall be currently certified by the NRMCA.

2.5.3 Mixers

2.5.3.1 Mixers may be stationary mixers or truck mixers.

2.5.3.2 Mixers shall conform to the requirements of ASTM C-94.

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2.5.4 Transport Equipment

2.5.4.1 Transportation of concrete completely mixed in a stationary mixer shall be by truck agitator, truck mixer operating at agitator speed, or by non-agitating equipment.

2.5.4.2 Transportation of concrete partially mixed in a stationary mixer shall be by truck mixer.

2.5.4.3 All transport equipment shall conform to the requirements of ASTM C-94.

2.5.4.4 All transport equipment shall be currently certified by the

NRMCA.

2.5.4.5 Concrete deposited for slipforming shall be transported by non-agitating equipment or by truck agitators.

2.5.5 Transfer and Spreading Equipment

2.5.5.1 Equipment for transferring concrete from the transporting equipment to the paving lane in front of the paver shall be specially manufactured, self-propelled transfer equipment which will accept the concrete outside the paving lane and will transfer and spread it evenly across the paving lane in front of the paver and strike off the surface evenly to a depth which permits the paver to operate efficiently.

2.5.6 Paver-Finisher

2.5.6.1 General:

a. The paver-finisher shall be a heavy-duty, self-propelled machine designed specifically for paving and finishing high quality pavement.

b. The paver-finisher shall weigh at least 2200 pounds per foot of lane width, and shall be powered by an engine having at least 6.0 horsepower per foot of lane width.

c. The paver-finisher shall spread, consolidate, and shape the plastic concrete to the desired cross section in one pass.

d. The mechanisms for forming the pavement shall be easily adjustable in width and thickness and for required crown.

e. In addition to other spreaders required by paragraph above, the paver-finisher shall be equipped with a full

April 2019 Page 18 Section 32 13 11 width knock-down auger or paddle mechanism, capable of operating in both directions, which will evenly spread the fresh concrete in front of the screed or extrusion plate.

2.5.6.2 Vibrators:

a. Immersion vibrators shall be gang mounted at the front of the paver on a frame equipped with suitable controls so that all vibrators can be operated at any desired depth within the slab or completely withdrawn from the concrete, as required.

b. The vibrators shall be automatically controlled so that they will be immediately stopped as forward motion of the paver ceases.

c. The spacing of the immersion vibrators across the paving lane shall be as necessary to properly consolidate the concrete.

d. The clear distance between vibrators shall not exceed 30 inches.

e. The outside vibrators shall not be more than 12 inches from the lane edge.

f. Spud vibrators shall operate at a frequency of not less than 8000 impulses per minute with an amplitude of not less than 0.03 inch, as determined by COE CRD-C 521.

2.5.6.3 Screed or Extrusion Plate:

a. The paver-finisher shall be equipped with a transversely oscillating screed or an extrusion plate to shape, compact, and smooth the surface and shall so finish the surface that no significant amount of hand finishing, except use of cutting straightedges, is required.

b. The screed or extrusion plate shall be constructed to provide adjustment for a crown in the pavement.

c. The entire machine shall provide adjustment for variation in lane width or thickness and to prevent more than 8 inches of the screed or extrusion plate extending over previously placed concrete on either end when paving fill-in lanes.

d. Machines that cause displacement of properly installed forms or cause ruts or indentations in the prepared underlying materials and machines that cause frequent delays due to mechanical failures shall be replaced as directed.

April 2019 Page 19 Section 32 13 11

2.5.6.4 Fixed Forms:

a. The paver-finisher shall be equipped with wheels designed to ride the forms, keep it aligned with the forms, and spread the load so as to prevent deformation of the forms.

b. Paver-finishers traveling on guide rails located outside the paving lane shall be equipped with wheels when traveling on new or existing concrete to remain.

2.5.6.5 Slipform:

a. The slipform paver-finisher shall be automatically controlled and crawler mounted with padded tracks so as to be completely stable under all operating conditions.

b. The paver-finisher shall finish the surface and edges so that no edge slump beyond allowable tolerance occurs.

c. Suitable moving side forms shall be provided that are adjustable and will produce smooth, even edges, perpendicular to the top surface and meeting specification requirements for alignment and freedom from edge slump.

2.5.6.6 Longitudinal Mechanical Float:

a. A longitudinal mechanical float shall be specially designed and manufactured to smooth and finish the pavement surface without working excess paste to the surface.

b. It shall be rigidly attached to the rear of the paver-finisher or to a separate self-propelled frame spanning the paving lane.

c. The float plate shall be at least 5 feet long by 8 inches wide and shall automatically be oscillated in the longitudinal direction while slowly moving from edge to edge of the paving lane, with the float plate in contact with the surface at all times.

2.5.6.7 Non-rotating Pipe Float:

a. A pipe float if used, shall be a nonrotating pipe 6 to 10 inches in diameter and sufficiently long to span the full paving width when oriented at an angle of approximately 60 degrees with the centerline.

b. The pipe float shall be mounted on a self-propelled frame that spans the paving lane.

c. No means of applying water to the surface shall be incorporated in the pipe float.

April 2019 Page 20 Section 32 13 11

2.5.6.8 Other Types of Finishing Equipment:

a. Clary screeds, other rotating tube floats, or bridge deck finishers shall not be used on mainline paving.

b. Clary screeds, other rotating tube floats, or bridge deck finishers may be used on irregular or odd-shaped slabs, and near buildings or trench drains as approved by the CO.

c. Bridge deck finishers shall have a minimum operating weight of 7500 pounds and shall have a transversely operating carriage containing a knock-down auger and a minimum of two immersion vibrators.

d. Vibrating screeds or pans shall be used only for isolated slabs where hand finishing is permitted as specified, and only where specifically approved.

2.5.7 Forms (reference Section 03 11 13)

2.5.7.1 Forms shall be steel, except that wood forms may be used on curves having a radius of 150 feet or less, and for fillets.

2.5.7.2 Forms shall be equal in depth to the edge thickness of the slab as shown.

2.5.7.3 All forms shall be set on firm material cut true to grade so that each form section when placed will be firmly in contact with the underlying layer for its entire length and base width.

2.5.7.4 Steel forms shall be furnished in sections not less than 10 feet in length, except that on curves having a radius of 150 feet or less they may be 5 feet but must be flexible or curved to the proper radius.

2.5.7.5 Each 10-foot length of form shall be provided with at least three form braces and pin sockets so spaced that the form will be rigidly braced throughout its length.

2.5.7.6 Lock joints between form sections shall be free from play or movement.

2.5.7.7 Forms shall be free or warps, bends, or kinks.

2.5.7.8 The top surface of a form shall vary not more than 1/8 inch in 100 feet from a true line.

2.5.7.9 The face of the form shall vary not more than 1/4 inch in 10 feet from a true plane.

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2.5.7.10 Forms with battered top surfaces or distorted faces or bases shall be removed from the project site.

2.5.8 Curing Equipment

2.5.8.1 Equipment for applying membrane-forming curing compound shall be mounted on a self-propelled frame that spans the paving lane.

2.5.8.2 The reservoir for curing compound shall be constantly mechanically (not air) agitated during operation and shall contain means for completely draining the reservoir.

2.5.8.3 The spraying system shall consist of a mechanically powered pump which will maintain constant pressure during operation, an operable pressure gauge, and either a series of spray nozzles evenly spaced across the lane to give uniformly overlapping coverage or a single spray nozzle which is mounted on a carriage which automatically traverses the lane width at a speed correlated with the forward movement of the overall frame.

2.5.8.4 All spray nozzles shall be protected with wind screens.

Calibrate the spraying system in accordance with ASTM D 2995, Method A, for the rate of application required in paragraph: Membrane Curing. Any hand-operated sprayers allowed by that paragraph shall be compressed air supplied by a mechanical air compressor. If the curing equipment fails to apply an even coating of compound at the specified rate, it shall immediately be replaced.

2.5.9 Texturing Equipment

2.5.9.1 General:

a. Before use, the texturing equipment shall be demonstrated on a test section, and the equipment shall be modified as necessary to produce the texture specified.

2.5.9.2 Burlap Drag:

a. A burlap drag shall be securely attached to a separate wheel mounted frame spanning the paving lane or to one of the other similar pieces of equipment.

b. The length of the material shall provide 24 to 36 inches dragging flat on the pavement surface.

c. The width shall be at least equal to the width of the slab.

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d. The material shall be clean, reasonably new burlap, completely saturated with water before attachment to the frame and kept clean and saturated during use.

e. Burlap shall conform to AASHTO M 182, Class 3 or 4.

2.5.9.3 Broom:

a. The broom shall be an approved mechanical stiff bristle broom drag of a type that will uniformly score the surface transverse to the pavement center line.

b. The broom shall be capable of traversing the full width of the pavement in a single pass at a uniform speed and with a uniform pressure.

c. The scores shall be uniform in appearance and approximately 1/16 inch in depth but not more than 1/8 inch in depth.

2.5.9.4 Artificial Turf:

a. The artificial turf drag shall be full-width and the leading transverse edge shall be securely fastened to a lightweight pole on a traveling bridge.

b. At least 2 feet of the artificial turf shall be in contact with the concrete surface during texturing operations.

c. The corrugations shall be uniform in appearance and approximately 1/16 inch in depth.

2.5.9.5 Deep Texturing Equipment:

a. Deep texturing equipment shall consist of a comb with spring wire tines forming a drag at least 4 feet long.

b. The drag shall be mounted in a wheeled frame spanning the paving lane and so constructed that the drag is mechanically pulled in a straight line across the paving lane perpendicular to the centerline.

2.5.10 Sawing Equipment

2.5.10.1 Equipment for sawing concrete shall be a standard diamond-type concrete saw mounted on a wheeled chassis which can be easily guided to follow the required alignment.

2.5.10.2 Blades shall be diamond tipped.

2.5.10.3 All saws shall be capable of sawing to the full depth required.

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2.5.10.4 Early-entry saws may be used after a demonstration and approval by the Contracting Officer.

2.5.10.5 No change to the initial saw cut depth shall be permitted.

2.5.11 Straightedge

2.5.11.1 Furnish and maintain at the job site, in good condition, one 12 foot straightedge for each paving train for testing the hardened Portland cement concrete surfaces.

2.5.11.2 These straightedges shall be constructed of aluminum or magnesium alloy and shall have blades of box or box-girder ` cross section with flat bottom, adequately reinforced to insure rigidity and accuracy.

2.5.11.3 Straightedges shall have handles for operation on the pavement.

2.6 SPECIFIED CONCRETE STRENGTH AND OTHER PROPERTIES

2.6.1 Specified Flexural Strength

a. The specified flexural strength, R, for concrete shall be as specified in the SOW and on the approved drawings.

b. The specifications for the plastic properties of the concrete shall be as give in SECTION 03 30 00, Table 1.

c. The maximum allowable slump for slip formed pavement shall be determined at the start of the project and shall produce in-place pavement meeting the specified tolerances for control of edge slump. The selected slump shall be remain in effect throughout the project and shall be applicable to both pilot and fill-in lanes.

2.6.2 Acceptance Testing Of Concrete

a. Acceptance testing for both plastic and hardened concrete shall conform to the requirements of SECTION 03 00 01, Concrete Construction; SECTION 03 30 00, Portland Cement Concrete and section 3.3 of this specification.

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2.6.3 Concrete Mix Proportions

2.6.3.1 Composition

a. Concrete shall be composed of cementitious material, water, aggregates and admixtures as specified in SECTION 03 30 00.

2.6.3.2 Proportioning Studies

a. The basis for all designs and proportions shall be 1 cubic yard yielding 27.0 cubic feet.

b. Aggregate weights and volumes shall be based on a saturated surface dry (SSD) condition of the material.

c. Mix designs shall be proportioned in accordance with ACI

211.1, modified as necessary to accommodate flexural strength.

d. Trial design batches, mixture proportioning studies, and testing requirements are the responsibility of the Contractor.

e. Submit the results of the mixture proportioning studies signed and stamped by the Licensed Professional Engineer having technical responsibility for the mix design study.

f. Submit all results at least 30 days prior to commencing concrete placing operations.

g. The results shall include a statement giving the maximum nominal coarse aggregate size and the weights and volumes of each ingredient.

h. The recommended mixture proportions shall be accompanied by test results demonstrating that the proportions selected will produce concrete of the qualities indicated.

i. Submit test results including:

a. Coarse and fine aggregate gradations and plots.

b. Combined aggregate gradation plots.

c. Coarse aggregate quality test results, including deleterious materials.

d. Fine aggregate quality test results, including deleterious materials.

e. Mill certificates for cement and supplemental cementitious materials.

f. Certified test results for all admixtures.

g. Specified flexural strength, slump, and air content.

h. Documentation of required average CQC flexural strength, Ra.

i. Recommended proportions/volumes for proposed mixture and each of three trial water-cementitious materials ratios.

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j. Individual beam breaks.

k. Flexural strength summaries and plots.

l. Correlation ratios for acceptance testing and CQC testing.

m. Historical record of test results, documenting production standard deviation (if available).

2.6.3.3 Water to Cementitious Ratio (w /(c+scm))

a. All water above SSD, including water in admixtures, shall be used to determine the water / cementitious ratio.

b. The maximum allowed water to cementitious ratio for airfield paving shall be 0.45.

c. At least three different water-cement ratios, each producing concrete of the strength required, shall be evaluated.

2.6.3.4 Trial Mixture Studies

a. Laboratory trial mixtures shall be proportioned for maximum allowable slump and air content.

b. Separate sets of trial mixture studies shall be made for each combination of cementitious materials and each combination of admixtures proposed for use.

c. No combination of either shall be used until proven by such studies, except that, if approved in writing and otherwise permitted by these specifications, an accelerator or a retarder may be used without separate trial mixture study.

d. Separate trial mixture studies shall also be made for concrete for each placing method (slip form, fixed form, or hand placement) proposed.

e. The temperature of concrete in each trial batch shall be reported.

f. Each mixture shall be designed to promote easy and suitable concrete placement, consolidation and finishing, and to prevent segregation and excessive bleeding.

2.6.3.5 Mixture Proportioning for Flexural Strength

The following step by step procedure shall be followed:

a. All beam molds shall be 6” x 6” x 24” steel.

b. All beams for each mix shall be fabricated from the same batch or blend of batches.

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c. All beams shall be fabricated and cured in accordance with the requirements of ASTM C 192.

d. Test 6 beams each at ages of 3, 7, 14, 28 and 56 days in accordance with ASTM C 78.

e. Plot the average of each age for each of the 3 w/c ratios on a separate graph.

f. From these graphs select a w/c that will produce a mixture providing the required flexural strength as determined below.

g. From the graph for the selected w/c determine the expected ratio of 7 day to 28 day strength to be used for CQC control.

h. New mixture design studies shall be performed and new ratios established if there is any change in materials.

i. No concrete pavement shall be placed until concrete submittals are approved by the government.

j. Concrete mixtures may be submitted and approved based on 28 day data at the discretion of the government.

2.6.3.6 Required Flexural Strength (Ra)

a. In order to ensure the concrete meets the specified flexural strength (R), the mixture proportions selected during proportioning studies and used during construction shall produce a required average flexural strength (Ra) exceeding R by the amount indicated below. During production, Ra shall be adjusted as approved based on the standard deviation of 7 day strengths being attained during paving.

b. Initial Ra to be used for proportioning and until 15 production tests results are available shall be:

Ra = R + 0.15R

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c. Production Ra shall be:

Ra = R + 1.34SM

Ra = Required Flexural Strength R = Specified Flexural Strength S = Standard Deviation M = Standard Deviation Modifier

d. The standard deviation shall be further modified, based on the number of tests, according to the following:

Number of Production Tests

Modification Factor (M)

15 to 19 1.16

20 to 24 1.08

25 to 29 1.03

30 or more 1.00

e. The standard deviation shall be computed from the 30 most current tests no older than 18 months.

f. The standard deviation may be computed from tests results on an existing mix if:

1. The specified flexural strength of the mix is within 50 psi of specified flexural strength for the proposed work (= R ± 50 psi),

2. All tests are current to within 18 months,

3. All materials are the same as the materials to be used in the proposed work and

4. The concrete represented was used in paving.

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PART 3 EXECUTION

3.1 PREPARATION FOR PAVING

3.1.1 Before commencing paving, the following shall be performed:

3.1.1.1 Surfaces to receive concrete shall be prepared as specified

3.1.1.2 If used, forms shall be in place, cleaned, coated, and adequately supported.

3.1.1.3 Any reinforcing steel needed shall be at the paving site.

3.1.1.4 All transporting and transfer equipment shall be ready for use, clean, and free of hardened concrete and foreign material.

3.1.1.5 Equipment for spreading, consolidating, screeding, finishing, and texturing concrete shall be at the paving site, clean and in proper working order.

3.1.1.6 All equipment and material for curing and for protecting concrete from weather or mechanical damage shall be at the paving site, in proper working condition, and in sufficient amount for the entire placement.

3.1.1.7 When hot, windy conditions during paving appear probable, equipment and material shall be at the paving site to provide windbreaks, shading, fogging, or other action to prevent plastic shrinkage cracking or other damaging drying of the concrete.

3.2 CONDITIONING OF UNDERLYING MATERIAL

3.2.1 General Procedures

3.2.1.1 Underlying material, subgrade, base course, or sub-base course, upon which concrete is to be placed shall be clean, damp, and free from debris, waste concrete or cement, frost, ice, and standing or running water.

3.2.1.2 Prior to setting forms or placement of concrete, the

underlying material shall be well drained and shall have been satisfactorily graded and uniformly compacted in accordance with the applicable Section of these specifications.

3.2.1.3 The surface of the subgrade or base course shall be tested as to crown, elevation, and density in advance of setting forms or of concrete placement using slip-form techniques.

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3.2.1.4 High areas shall be trimmed to proper elevation.

3.2.1.5 Low areas shall be filled and compacted to a condition similar to that of surrounding grade, or filled with concrete monolithically with the pavement.

3.2.1.6 Where low areas are filled with concrete, the areas shall be marked, as approved, and cores for strength and thickness shall not be drilled in those areas.

3.2.1.7 Any underlying material disturbed by construction

operations shall be reworked and re-compacted to specified density immediately in front of the paver.

3.2.1.8 If a slip form paver is permitted and is used, the same underlying material under the paving lane shall be continued beyond the edge of the lane a sufficient distance and shall be thoroughly compacted and true to grade to provide a suitable track line for the slip-form paver and firm support for the edge of the paving lane.

3.2.1.9 Where an open-graded granular base is required under the concrete, the Contractor shall select paving equipment and procedures, which will operate properly on the base course without causing displacement or other damage.

3.2.2 Traffic on Underlying Material

3.2.2.1 After the underlying material has been prepared for

concrete placement, no equipment shall be permitted thereon.

3.2.2.2 Subject to specific approval, crossing of the prepared subgrade or base course at specified intervals for construction purposes may be permitted provided rutting or indentations do not occur; however, if traffic has been allowed to use the prepared subgrade or base course, the surface shall be reworked and re-prepared to the satisfaction of the Contracting Officer before concrete is placed.

3.3 WEATHER LIMITATIONS

3.3.1 Placement and Protection During Inclement Weather

3.3.1.1 The Contractor shall not commence placing operations when heavy rain or other damaging weather conditions appear imminent.

3.3.1.2 At all times when placing concrete, the Contractor shall maintain on-site sufficient waterproof cover and means to rapidly place it over all unhardened concrete or concrete that might be damaged by rain.

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3.3.1.3 Placement of concrete shall be suspended whenever rain or other damaging weather commences to damage the surface or texture of the placed unhardened concrete, washes cement out of the concrete, or changes the water content of the surface concrete.

3.3.1.4 All unhardened concrete shall be immediately covered and protected from the rain or other damaging weather. Any pavement damaged by rain or other weather shall be completely, by jointed section, removed and replaced at the Contractor's expense.

3.3.2 Paving in Hot Weather

3.3.2.1 When concrete is to be placed under or exposed to hot weather conditions, a description of the methods proposed for cooling aggregate and water and the methods used to prevent evaporation in excess of 0.2 psf per hour from the placed concrete shall be submitted to the Contracting Officer for approval.

3.3.2.2 The temperature and placement requirements of Section 03 30 00; PORTLAND CEMENT CONCRETE shall apply.

3.3.2.3 During periods of hot weather, when the maximum daily air temperature is likely to exceed 85 degrees F, the forms and underlying material shall be sprinkled with water immediately before placing concrete.

3.3.2.4 When necessary, approved methods will be used to keep the temperature of the mixed concrete below 90 degrees F.

3.3.3 Paving in Cold Weather

3.3.3.1 No concrete for paving shall be mixed unless the air

temperature is 45 degrees F. and rising.

3.3.3.2 Paving shall not be placed on ice or any frozen subgrade.

3.3.3.3 The Contracting Officer shall…