603CONCRETE PAVEMENT

- 403 - SECTION 603 -- CO NCRETE PAVEMENT

603.01Description

Portland cement concrete pavements, approach slabs, and headers. They are to be constructed on a prepared subgrade, modified subgrade or foundation course.

603.02Material Requirements

slabs shall be as specified in the contract.

to the requirements of the Sections shown in Table 603.01. Table 603.01 Material Requirements Applicable Materials Section Curing Materials ............................................. 101 0, 1011, 1012, 1013 Preformed Polychloroprene Elastomeric Reinforcing Steel ............................................ 1020, 1021, 1024

603.03Construction Methods

the requirements of Secti on 307 or in the contract.

subgrade or foundation course.

construction staking provided by the Department or by the Contractor if Contractor Staking is required.

that the Contractor prep ares a digital terrain model (DTM) to a system specifically designed to control the paving equipment. The Contractor shall provide elevations from the DTM at key locations selected by the Engineer,

Concrete Pavement

- 404 - such as but not limited to, inlets, bridge approaches, intersections, and superelevations.

metal forms of the proper radii shall be used for curves having radii of less than 100 feet (30 m).

pinned and staked to line and grade.

section, consolidated, leveled, and fi nished to the grade shown in the contract.

concrete placement as directed by the Engineer.

permission from the Engineer 24 hours in advance of placement.

temperature reaches 40°F (5°C) or when a forecasted descending temperature is expected to fall below 40°F (5°C) during placement. Mixing and placing operations shall be discontinued when the descending ambient air temperature reaches 40°F (5°C).

(5°C) shall be as described in Subsection 704.03. Any concrete damaged by freezing shall be rejected.

following maximum limits:

within 30 minutes of it being placed on the grade. (2). Concrete shall not be k ept in non-agitating trucks (i.e., dump trucks) more than 30 minutes.

90 minutes.

work stops for more than 30 minutes. However, no section's length shall be less than 10 feet (3 m).

joints shall be replaced or repaired as directed by the Engineer. No payment will be made for this work.

bars in lieu of tie bar pins shown in t he contract. It must be located in the paving train so as to place tie bars prior to the placement of the wire mesh on reinforced concrete pavement, or prio r to the passage of the first finishing machine on non-reinforced concrete pavement.

segregation, honeycombing, or large voids. .03

- 405 - 5. Slip-Form Placing Concrete:

transverse vibrating units or a series of longitudinal vibrating units.

paver.

the finished surface of the slab, and paralle l to the centerline of the roadway.

mechanical inserters.

(6 mm) in both the horizontal and vertical planes. The Engineer may elect to dig into the plastic concrete to verify dowel bar orientation and location. The subsequent hole shall be repaired by the Contractor at no additional expense to the Department.

assemblies shall be suitable for the joint layout as shown in the contract. The assemblies shall be dipped in an asphaltic bond breaker found on the Approved Products List prior to delivery to the work site.

placed at all transverse joints where doweled concrete is required, and shall be securely pinned to the grade to prevent any movement during the paving operation. Pins shall be placed at a maximum distance of three feet (1 m) apart and shall be a minimum of 12 inches (300 mm) in length. All lateral support braces shall not be cut after the baskets are secured and prior to placing the concrete.

be used. Assemblies damaged after placement shall be replaced prior to paving.

constructed perpendicular to the roadwa y on 16 foot 6 inch (5 m) centers.

placed in all transverse joints which are 6 feet (1.8 m) or wider.

panels between load transfer joints shall be replaced or repaired as directed by the Engineer. No payment will be made for this work.

consolidated layer of concrete whose top surface is at the elevation specified for the reinforcing metal.

(300 mm).

laps.

exceed 2 feet (600 mm).

Concrete Pavement

- 406 - (4) The transverse laps shall be tied with a minimum of 3 ties per lane width. (5). Any portion of the bottom layer of concrete that has been placed more than 30 minutes without being covered with the top layer shall be rejected.

Table 603.02. Table 603.02 TIE BARS FOR LONGITUDINAL JOINTS Slab Thickness Bar Size* Bar Spacing 5” (125 mm) 6-10” (150-250 mm) More Than 10” (250 mm) #4 (#13) #5 (#16) #6 (#19) 24” (610 mm) 33” (840 mm) 33” (840 mm) *#5 bars will be used in place of #6 bent bars that must be straightened.

in lieu of tie bar pins.

only when the paver to which it is attached is moving.

in one quick, continous movement resu lting in maximum contact of plastic concrete around the bar with no void created behind the bar.

except in emergencies to complete the day’s concrete placement.

attain a minimum 12,000 lb pullout strength once the concrete reaches a minimum 3500 psi compressive strength. NDOT may perform pullout testing for verification at any time.

the nominal spacing shown. The number of tie bars per 16 feet 6 inch (5 m) panel shall remain constant.

spacing to a transverse joint.

bars placed at key-type longitudinal joints may have a 90 degree bend at the center of the bar to facilitate placement.

degrees to the longitudinal joint.

horizontally from the dowel bar at the transverse joint.

.03

- 407 - (4) All bars that crack or break off shall be replaced by installing tie bars as described in Section 909. Cracked or broken bars shall be replaced at no additional cost to the Department.

damaged by straightening bars to a 45° angle does not need to be repaired.

consolidated and finished to the specified finished grade.

of the transverse-screed type. The finishing machine shall be equipped with two oscillating type transverse screeds. The front screed shall be used for striking off excess concrete to exact grade and crown. The rear screed shall be used for finishing and smoothing. All screeds shall be constructed of steel, capable of being adjusted to the s pecified cross section and shall be of such rigidity as to produce the specif ied crown and cross section. Both the machine and the screeds shall have variable speeds and be independently controlled.

or variable width sections where mechanical methods are impractical.

shall be vibrated until the concrete is thoroughly consolidated, then struck-off to a uniform height above the specifie d finished grade. It shall then be shaped with heavy vibrating screeds to the described cross section.

consolidate the plastic concrete within and around the dowel basket assemblies, adjustments to the mate rial and/or operations shall be made.

finishing operations is not allowed except for unavoidable delays or unusual drying conditions. Fogging the concrete surface may be required to aid finishing. The fog shall be applied as a mist by means of an approved "orchard" sprayer.

concrete finishing, all placing operations shall be immediately stopped until the finishers catch up to a point where fogging for finishing is no longer required.

fogging. It shall be applied according to the manufacturer’s specifications with approval by the Engineer.

profile with a 10 foot (3 m) straightedge.

be lapped one-half their length in each successive position. High areas shall be removed, depressions filled with fresh concrete, and the concrete consolidated with hand floats.

all irregularities have been satisfactorily corrected.

Concrete Pavement

- 408 - d. Pavement that will not be tined shall be textured by dragging a wet burlap, carpet, or canvas belt over the full width of the surface in a longitudinal direction.

allowed.

through a uniform, fogging spray pattern. The addition of water to the drag shall not produce unsatisfactory conditions such as puddling, dripping, or excessive paste on the surface.

device, to insure a uniform texture.

pavement when the paving train is not in motion for 30 minutes or more and carefully reset before resuming the dragging operations.

uniform surface. Drags that cannot be cleaned shall be replaced.

joints shall be prepared and the concrete over the joints carefully removed. The edges of the pavement along the side forms and joints shall be rounded with an edging tool.

40 mph or greater; the Contractor sha ll tine texture the concrete pavement surface using the following methods:

grooves parallel to the centerline of t he road approximately 1/8 inch (3 mm) wide and 1/8 inch (3 mm) deep spaced at 3/4 inch (19 mm) on center. A 2 inch (50 mm) to 3 inch (75 mm) wide strip of pavement surface shall be protected from surface grooving for th e length of and centered along the longitudinal joint.

cover the full pavement width in a single pass at a uniform speed and depth centered on the longitudinal joint. Longitudinal tining shall be accomplished by equipment with horizontal and vertical string line controls to ensure straight grooves.

inaccessible to the tining machine. A tine rake shall be used for hand tining. The use of a corrugated bull float or other device that creates a smooth finish between the grooves will not be permitted.

specified requirements shall be textured only after the concrete has attained its designed strength. T he texturing shall be done with diamond grinding equipment specifically designed to grind and texture concrete pavements. The cutting head shall be at least 36 inches (915 mm) wide and capable of producing the depth and spacing indi cated above. This work shall be performed at no additional cost to the Department. .03

- 409 - 10. Protection:

the ambient air temperature is expected to drop below 35° F (2 C) within 72 hours. The Contractor shall supply min/ max thermometers at 200 ft intervals at no additional cost to the Departmen t. The Contractor shall spread straw, hay, or other suitable blanketing mate rial over the pavement to a sufficient depth to keep the concrete from freezi ng. The blanket material shall be covered with a layer of burlap or plastic sheeting, weighted or anchored to prevent the wind from displacing the insulation. The protection shall be maintained for 10 days or until openi ng strength is obtained, whichever occurs first.

installed before plastic shrinkage cracking, "hair-checking", develops.

2/h), the Contractor must notify the Engineer regarding the additional actions that will be taken to prevent plastic shrinkage cracking. The rate of evaporation shall be obtained by using the nomograph in Figure 706.01.

following methods:

within 45 minutes after the pass of the paving machine.

pavement surface, curbs, and edges with or without tie bars shall be covered with a continuous uniform coating of white-pigmented curing compound as described in Section 1012.

surface that will be bonded to another concrete surface except for slip- formed pavement. All surfaces of slip-formed pavement shall receive a coat of curing compound.

applications. The second application shall be made a minimum of 10 feet behind the first application.

at a minimum of 1 Gal/100 SF (0.4 L/m2) [0.5 Gal/100 SF (0.2 L/m2) each application] of surface area for tined su rfaces or 1 Gal/150 SF (0.3 L/m2) of surface area for all other finishes.

shall be covered with the curing compound within 30 minutes after removal of the forms.

used to apply the curing compound to the concrete pavement. Hand- powered spraying equipment may be employed in an emergency and on narrow or variable width sections where the use of a mechanical power sprayer is impractical.

Concrete Pavement

- 410 - (a) The mechanical power sprayer shall not ride on the uncured pavement surface.

entire lane width and thoroughly atomize the curing-compound.

unsatisfactory result, such as puddles , dripping, or non-uniform application, the paving operation shall be suspended until appropriate changes have been made.

prevent uncontrolled dispersal by the wind.

result during the joint sawing operations, shall be recoated without delay using the same application rate orig inally described. Recoating shall be performed at no additional cost to the Department.

burlap-polyethylene sheets:

operations, the top surface of the pavement shall be covered with a white opaque polyethylene film or white burl ap-polyethylene sheeting conforming to the requirements of Section 1010. Plac ement of the film or sheeting shall be done to avoid damaging the concrete surface.

pavement in conformance with the following:

kept off the concrete while placing the material.

and vertical pavement surfaces.

18 inches (450 mm). The laps shall have a satisfactory anchor placed on them to form a closed joint.

film so that moisture is held inside the covering to facilitate curing.

repaired immediately by cementin g patches over the openings.

provided that it is kept in serviceable condition by proper repairs, and provided also that it will maintain a watertight covering during the curing period.

with film or sheeting, properly sealed, for 72 consecutive hours following the placing of the concrete except that, the film or sheeting may be temporarily removed so that joints may be sawed. While the pavement is uncovered, it shall be kept wet by sprinkling with water.

sheeting shall be double sewn. .03

- 411 - (iv) Joints and seams in polyethylene film or sheeting shall have a minimum lap of 18 inches (450 mm), and sheeting shall be securely cemented together.

prevent separation during the curing period.

operations, burlap shall be carefully placed on the concrete and kept moist. Placement of burlap shall be done to avoid damaging the concrete surface.

Section 1011 and shall be of sufficient length to cover all exposed surfaces, including the vertical edges of the slab.

banked so that the top width of the berm shall be at least 6 inches (150 mm).

water for at least 72 hours following the placing of the concrete, except that the burlap may be temporarily removed so that the joints may be sawed. While the pavement is uncovered, it shall be kept wet by sprinkling with water. Concrete operations shall be suspended when water is not available to cure the concrete.

contract or when “early-cut” type sawi ng of the joint, the cut shall be the depth recommended by the manufacturer. Curbed sections must be cut with a saw equipped with a diamond tipped blade.

the weight of the saw and sawing does not create raveling. Sawing must be completed before random cracking occurs.

location by more than 5% of the described spacing.

from the center of the dowel's length.

one continuous pass.

considered unacceptable. The Engineer will decide whether to replace or repair the panel. The Cont ractor shall replace or r epair these panels at the direction of the Engineer at no cost to the Department. A 20% deduction will be assessed on any repaired panel. Any panel that is replaced will not be assessed a 20% deduction.

depths to prevent random cracking.

Engineer.

manufacturer's recommendations.

Concrete Pavement

- 412 - (1) Before sealing, the joint wall (not the bottom of joint) surfaces shall be sandblasted or water-blasted to remove all dirt, curing compound residue, laitance, and any other foreign material. The Engineer may require additional measures, such as resawing, if the blasting techniques are ineffective. After sandblasting, the entire joint shall be cleaned with compressed air having a minimum pressure of 90 psi (620 kPa). The compressed air shall be free of oil, water, and other contaminants. The joints shall be dry at the time of sealing.

shall be sealed so that the joint is filled to approximately 1/4 inch to 5/8 inch (6 to 12 mm) below the top of the joint with an approved hot poured sealant.

surface of the pavement.

rejected, removed and replaced at no additional cost to the Department.

pour manufacturer's sealing recommendations two weeks prior to commencing work.

smoothness as described in Section 602.

contract. This curb shall be placed within 30 minutes after the slab has been placed and finished. That part of the pavement that will be attached to the integral curb shall be cleaned of all laitance and roughened to assure a good bond.

operation.

spacing shown in the contract.

be finished with a rough texture.

that used in the concrete slab. All c ontraction or expansion joints in the pavement shall be continuous through the integral curb.

approval has been given by the Engineer.

time the pavement is in place and/or on the compressive strength of the concrete as determined by cores taken from the pavement.

pavement when the concrete has reached a minimum age of 14 days or when the concrete has reached a compressive strength of 3,000 psi (21 MPa) when tested in accordance with ASTM C 39. .05

- 413 - d. With the approval of the E ngineer, the Contractor may elect to increase the early strength of the concrete by adding cement and/or reducing the water/cement ratio. The pavement may then be opened to traffic provided it has attained a comp ressive strength of 3500 psi (24 MPa). The concrete in the area where the ea rly strength is required shall be paid for at the bid price.

maturity method may be used to determine pavement compressive strength. The maturity method will be performed in accordance with NDOT C 1074 and in lieu of Subsection 603.03, Paragr aph 15.c. and d. to determine the strength of concrete pavement for the pur pose of early opening to traffic. Requests by the Contractor for use of the maturity method shall be on a project basis and shall be made in writing to the Engineer.

603.04Method of Measurement

(meter).

by the pound (kilogram).

measured according to the procedure in Section 602.

pavement will be measured to the outs ide edge of the beveled edge. The work required to form the beveled edge will be considered subsidiary to the concrete pavement being placed.

603.05Basis of Payment

_____ inch (mm) Doweled Square Yard (SY) Concrete Pavement _____ [Square Meter (m 2)] _____ inch (mm) Concrete Square Yard (SY) Pavement _____ [Square Meter (m2)] _____ inch (mm) Reinforced Square Yard (SY) Concrete Pavement_____ [Square Meter (m2)] Concrete for Pavement Cubic Yard (CY) Approaches _____ [Cubic Meter (m3)] Epoxy Coated Reinforcing Steel Pound (lb.) for Pavement Approaches [kilogram (kg)] Portland Cement Concrete Lump Sum (LS) Smoothness Testing Concrete for Headers, Cubic Yard (CY) C l a s s _ _ _ _ _ [ C u b i c M e t e r ( m3)]

unless changes are approved by the Engineer.

Concrete Pavement

- 414 - 3. Paving Units and Coring Program

compressive strength and thickness. Cores will be located randomly within each paving unit. Additional cores (special cores) for strength verification, thickness deficiency delineation or ot her anomalies may be taken at the discretion of the Engineer. These cores may be used in acceptance decisions.

be considered separately. Units are 750 linear feet (230 m) of pavement for each separately placed width, or width of each class of concrete whether or not placed separately starting at the beginning of the pavement.

750 feet (230 m) plus any fractional part of 750 feet (230 m) remaining.

750 feet (230 m), the l ength of the unit shall be the actual length.

constructed longitudinal joints, between a longitudinal construction joint and the edge, or between two pavement edges. A separately placed width may include more than one pay item of concrete, such as doweled and non- doweled.

exceptions to the unit’s length.

the normal width of pavement on eit her side shall be considered as continuing through in the same manner as would be applicable if the section under consideration had been placed continuously through the section.

compressive strength of 1 core per unit tested in accordance with ASTM C

The Contractor will have the option to obt ain two additional cores, at no cost to the Department, for any un it core that fails to have the required minimum compressive strength provided:

42 and tested within seven (7) days of being notified of the strength deficiency, under the super vision of the Engineer.

core in the longitudinal direction.

be averaged for the final compressive st rength calculation and pay factor.

more than 0.25 inch (6 mm), an additional core will be taken within 1 foot (300 mm) longitudinally of the primary core. The additional core can be used for compressive strength testing.

.05

- 415 - Table 603.03 Concrete Strength Pay Factor Percent of Required Concrete Compressive Strength Pay Factor Greater than 99.9 100 Greater than 98.5 to 99.9 99.75 Greater than 97.5 to 98.5 99.50 Greater than 96.0 to 97.5 99 Greater than 94.0 to 96.0 98 Greater than 92.0 to 94.0 97 Greater than 90.0 to 92.0 94 Greater than 88.0 to 90.0 90 Greater than 86.0 to 88.0 86 Greater than 84.0 to 86.0 81 Greater than 82.0 to 84.0 76 Greater than 80.0 to 82.0 70 Less than 80.0 See Paragraph 4.e of this Subsection

their cylinders. If the concrete cylinders’ compressive strengths are less than 2,000 psi (14 MPa) at 7 days, then the Engineer may require the concrete to be removed and replaced.

may allow concrete with a compressive strength of less than 80% of the required strength (after 28 days) to be left in place and paid for at 40% of the bid price or may require the unit to be removed and replaced.

shown in the contract. A pay factor shown in Table 603.04 will be applied to each unit based on the average thickness of cores tested in accordance with ASTM C 174.

irregular areas, blockouts, intersections, with widths less than 8 feet (2.4 m) or from an entire contract involving less than 5,000 square yards (4200 m 2) of pavement.

measurement of three caliper readings taken at 3 equidistant points on the core.

inch (6 mm) from plan thickness, full payment will be made and no additional cores will be required.

2 additional cores will be taken in the same unit. Whenever possible, the distance between cores should be approxim ately one third of the unit length.

Concrete Pavement

- 416 - (3) The average thickness of the 3 cores will then be determined. If the average thickness of these 3 cores is not deficient by more than 0.25 inch (6 mm), full payment will be made.

than 0.25 inch (6 mm) but not more than 0.50 inch (12.5 mm) an adjusted unit price will be paid in accordance with Table 603.04. Cores deficient by more than 0.50 inch (12.5 mm) wi ll be treated as described in Subection 603.05 5.d.

unit, measurements greater than contra ct thickness will be considered contract thickness.

more than 0.50 inch (12.5 mm) or special cores will not be used in determining average thickness.

(12.5 mm) will be deducted from the to tal area of the unit and pay for the remainder of the unit will be based on Table 603.04. Table 603.04 Payment Deductions Based on Deficient Pavement Thickness English Average Thickness Deficiency

Contract Unit Price 0 to 0.25 inch (0 to 6 mm) 100 Greater than 0.25 to 0.30 inch (6 to 7.6 mm) 85 Greater than 0.30 to 0.35 inch (7.6 to 8.9 mm) 80 Greater than 0.35 to 0.40 inch (8.9 to 10.2 mm) 75 Greater than 0.40 to 0.45 inch (10.2 to 11.4 mm) 70 Greater than 0.45 to 0.50 inch (11.4 to 12.5 mm) 65 Greater than 0.50 inch (12.5 mm) Remove and Replace* * When the thickness of the pavement is deficient by more than 0.50 inch (12.5 mm), the Engineer will evaluate the pavement’s expected use and may allow it to be left in place at 40% pay.

thickness by more than 0.50 inch (12.5 mm), the method to establish the limits of the 0.50 inch (12.5 mm) defic ient section will be determined by taking exploratory cores in the following manner.

deficient core’s locations on a line para llel to the centerline of the pavement.

no additional cores will be taken for this individual zone of deficiency.

(12.5 mm) tolerance, additional cores wi ll be cut on either si de of the original .05

- 417 - deficient core on a line parallel to t he centerline of the pavement. These additional cores shall be taken 25.0 feet (7.6 m) from the original core and then consecutive cores will be cut at 40 foot (15 m) intervals until a thickness within the 0.50 inch (12.5 mm) tole rance is found in both directions.

be to take a core approximately halfway between the first core that comes within the 0.50 inch (12.5 mm) toleranc e and the nearest core over 0.50 inch (12.5 mm) deficient.

minus 5 feet) (1.5 m) at which the pavement comes within the 0.50 inch (12.5 mm) tolerance is located.

defined in Table 603.04 for deficiencies greater than 0.50 inch (12.5 mm).

pavement under the following conditions:

concrete paving operations.

specification.

concrete (regardless of its intended us e) shall be determined as described by ASTM C 138.

less than 100% of the specified wei ght, then a deduction shall be made as described in Table 603.05.

adjusted by the cement content deduction pay factor shall include all concrete represented by the 10 consecutive tests.

consecutive tests is 100% or more of the specified weight and any individual test is less than 97%, then a deduction is made as described in Table 603.06.

adjusted by the cement content deduction pay factor shall include all concrete that is placed between the test just prior to the low percentage test and the first test following the low percent age test that is at or above 97%.

Concrete Pavement

- 418 - Table 603.05 PCC Concrete Deduction for Cement Content (Average of Ten Consecutive Tests) Average Cement Content – By Weight PCC Concrete Pay Factor 100 or greater 1.00 Less than 100 to 99.7 0.98 Less than 99.7 to 99.5 0.95 Less than 99.5 to 99.2 0.85 Less than 99.2 to 99.0 0.85 Less than 99.0 to 98.5 0.70 Less than 98.5 to 98.0 0.625 Less than 98.0 to 97.5 0.550 Less than 97.5 to 97.0 0.475 Less than 97.0 Remove and Replace* * The Engineer may elect to leave concrete in place and pay only 40% of bid price. Table 603.06 PCC Concrete Deduction for Cement Content (Individual Test) Cement Content Percentage (by weight) PCC Concrete Pay Factor 100 to 97 1.00 Less than 97.0 to 96.5 0.98 Less than 96.5 to 96.0 0.95 Less than 96.0 to 95.0 0.88 Less than 95.0 to 94.0 0.76 Less than 94.0 to 93.0 0.64 Less than 93.0 to 92.0 0.52 Less than 92 Remove and Replace* * The Engineer may elect to leave concrete in place and pay only 40% of bid price.

for any pavement, which has an average thickness greater than shown in the contract.

shall not be measured and paid for directly but shall be considered subsidiary to the concrete pavement.

considered as subsidiary to concrete pavement. .05

- 419 - 10. Furnishing and placing required reinforcement and dowel bars shall not be paid for directly but will be considered as subsidiary to concrete pavement.

subsidiary to c oncrete pavement.

item will be subdivided so that the quantities of the various types and thicknesses will be identified.

shall be considered subsidiary to the items of work for which direct payment is made.

- 420 - SECTION 604 -- CONCRETE BASE COURSE

604.01Description

base course composed of Portland cement concrete. It shall be constructed on a prepared subgrade or foundation c ourse as shown in the contract.

604.02Material Requirements

to the requirements in Table 604.01. Table 604.01 Material Requirements Applicable Materials Section Reinforcing St eel ....................................... 1020, 1021, 1024 Curing Materials......................................... 101 0, 1011, 1012, 1013

604.03Equipment

described in Sections 601 and 603.

604.04Construction Methods

as described in Sections 30 1, 302, 303, 305, and 307.

pertinent sections of Section 603.

smoothness in both the transverse and long itudinal directions with a 10 foot (3 m) straightedge. The maximum allowable variation is 1/4 inch (6 mm). Base course not meeting this requirement will be evaluated by the Engineer and may be subject to corrective diamond grinding or other remedy.

placed on the base course, a bituminous liquid curing compound conforming to the requirements of Se ction 1013 shall be applied.

moisture retention tests, except that the rate of application shall never be less than 1 Gal/200 SF (2 L/m2) of surface area.

after being applied, the affected areas sh all be recoated without delay at the same rate described for the original application.

wearing or surface course after the concrete has cured 14 days or after