ITEM 451 REINFORCED PORTLAND CEMENT CONCRETE PAVEMENT
451.01
Description
451.02
Materials
451.03 Pavement
Quality Control
451.04
Equipment
451.05 Setting
Forms
451.06 Fine
Grading of Subgrade or Subbase
451.07 Placing
Concrete
451.08 Placing
Reinforcement
451.09 Joints
451.10
Finishing
451.11 Curing
451.12 Removing
Forms
451.13 Surface
Smoothness
451.14 Profile
Grinding
451.15 Pavement
Grooving Corrections
451.16 Sealing
Expansion Joints
451.17 Opening
to Traffic
451.18 Pavement
Thickness and Concrete Strength
451.19 Price
Adjustments
451.20
Method of Measurement
451.21 Basis of
Payment
451.01 Description. This work consists of
constructing a pavement composed of reinforced portland cement concrete on a prepared surface.
451.02 Materials. Furnish materials conforming to:
Concrete,
either Class QC 1, QC MS, QC FS.................... 499
* Class RCA................................ Supplement 1117
Joint
sealer........................................................... 705.04
Preformed
filler................................................... 705.03
Curing materials...... 705.05, 705.06,
705.07 Type 2
Tiebar steel, epoxy coated................................ 709.00
Reinforcing
steel.................... 709.09, 709.10, 709.12
Dowel bars and basket
assemblies.................. 709.13
* Use of Recycled
Concrete aggregate as part of a concrete mix can be accepted with conformance
to Supplement 1117
451.03 Pavement Quality Control. When the concrete pavement bid item
includes “with QC/QA”, provide complete quality control of the concrete
manufacturing, placing and curing operations and quality control testing of the
work conforming to Item 455. The Engineer will review and accept the plan prior
to beginning of any paving operations.
When
the concrete pavement bid item includes “with QC/QA” the Engineer will perform
Quality Assurance conforming to Item 455.
451.04
Equipment.
Furnish self-propelled spreading and finishing machines capable of
consolidating and finishing the concrete and producing a finished surface
meeting the requirements specified.
Construct
pavement using either fixed forms or slip form paving equipment that conforms
to the following:
A. Fixed Form Construction. Spread, screed, and consolidate concrete using
one or more machines between previously set side forms. Furnish an
adequate number and capacity of machines to perform the work at a rate equal to
the concrete delivery rate. Furnish machines capable of uniformly
distributing and consolidating the concrete without segregation.
Provide machines capable of operating on two side forms, on adjacent
lanes of pavement and one side form or on two adjacent lanes as
necessary. When placing concrete adjacent to an existing pavement lane,
take measures to protect the adjacent pavement from damage. Remove from
the work any machine that causes displacement of the side forms from the line
or grade or causes undue delay, as determined by the Engineer, due to
mechanical difficulties.
Finish small or irregular areas that are inaccessible to finishing
equipment using other methods as approved by the Engineer. Accomplish
vibration of these areas using hand held or machine mounted internal vibrators.
Continue vibration to achieve adequate consolidation, without segregation, for
the full depth and width of the area placed.
Use
straight edge side forms made of steel and of a depth equal to the specified
pavement thickness. Do not use bent or damaged side forms or forms with
damaged joint locks or pin pockets. Provide forms in sections of not less
than 10 ft (3 m) in length without horizontal joints
in the height of the form. Utilize forms with a nominal base width
of at least 3 inches (75 mm). Assure forms are capable of supporting the paving
equipment without shifting or deforming during paving.
Clean and oil all forms each time they are used. If the radius of
the circular pavement edge is 100 feet (30 m) or less, use flexible or curved
forms of a design acceptable to the Engineer. Provide adequate devices to
securely set forms and withstand operation of the paving equipment. Do
not use built-up forms except to construct pavement of a specified thickness
whose total area for the project is less than 2000 square yards (1650 m2).
Provide forms with adequate joint locks to tightly join ends of abutting form
sections together.
B. Slip Form Construction. Place concrete using an industry-standard slip form
paver designed to spread, consolidate, screed, and finish the freshly placed
concrete in one complete pass of the machine and with a minimum of hand
finishing providing a dense and homogeneous pavement.
Consolidate
the full width and depth of concrete pavement placed by a single pass of a
series of approved internal vibrators operating at a frequency range of 7000 to
11,000 impulses per minute. Attach vibrators to either the spreading or
finishing equipment in such a manner that they do not come in contact with
preset dowel basket assemblies, the subgrade, reinforcing mesh or side
forms. Do not operate vibrators in a manner to cause a separation of the
mix ingredients (segregation); i.e., either a downward displacement of large
aggregate particles or an accumulation of laitance on the surface of the
concrete. Avoidance of segregation of the concrete mix may require
reduction in the vibration frequency within the range specified when forward
motion of the paver is reduced. Connect the power to all vibrators so
that they cease when the machine motion is stopped. Stop paving
operations if any vibrator fails to operate within the above specified range.
Provide
an electronic monitoring device that displays the operating frequency of each
internal vibrator on all paving machines used on mainline and ramp
paving. The monitoring device shall have a readout display near the paver
operator’s controls that is visible to the operator and the Engineer.
Operate the monitoring device continuously while paving and display all
vibrator frequencies with manual or automatic sequencing among individual
vibrators. Using the monitoring system record the following minimum
information: time of day, station location, paver track speed, and the
frequency of each individual vibrator. Make recordings after each 25 feet
(8 m) of paving or after 5-minute intervals of time. If not using a
monitoring system with a recorder, make and record readings every 30
minutes. If requested by the Engineer, provide a record of the data.
Electronic
vibration monitoring devices are not required for paving machines used to
construct shoulders and gores or for any construction project with a total of
less than 10,000 square yards (8000 m2) of pavement. When
electronic monitoring devices are not required, use a tachometer or similar
device to demonstrate to the Engineer the paving equipment vibration meets
specification.
Operate the slip form paver with as nearly a continuous forward
movement as possible, and coordinate all operations of mixing, delivering, and
spreading concrete to provide uniform progress with minimal stopping and
starting of the paver. If for any reason it is necessary to stop the
forward movement of the paver, immediately stop the tamping elements.
Unless controlled from the machine, do not apply any other tractive force to
the machine.
Accurately control
the finish grade of the pavement from a pre-set grade line parallel to the
finish grade using equipment with controls that will trace the grade line and
automatically adjust the grade of the screeds or extension meters.
In areas where
adjoining concrete pavement is to be constructed, ensure that the surface at
the edge of the pavement on either side of the longitudinal joint does not vary
more than 1/4 inch (6 mm) below the typical section. Ensure that the
outside edges of the pavement does not vary more than 1/2 inch (13 mm) below
the typical section. Ensure that all pavement edges are nearly vertical
with no projections or keyways exceeding 1/2 inch (13 mm).
In the area of
construction joints placed at the end of the days run, the Engineer will allow
a reduction of approximately 2 inches (50 mm) in overall width.
451.05 Setting Forms. Set all forms in
conformance to the required grade and alignment and support the entire length
of forms on thoroughly compacted material during the entire operation of
placing and finishing of the concrete. Set side
forms with the top face of the form varying not more than 1/8 inch in 10 feet
(3 mm in 3 m) from true plane, and the vertical face varying not more than 1/4
inch in 10 feet (6 mm in 3 m) from true plane. Test the forms for
variations from the above requirements and reset the forms as necessary.
Do not use loose earth, pebbles, etc., to shim the forms. Immediately
before placing concrete, the Engineer will approve the alignment and grade of
all forms set.
451.06 Fine Grading of Subgrade or Subbase.
A. Fixed Form Construction. After side forms have been set to line and
grade and securely fastened, use a subbase or
subgrade planer to remove a slight amount of material and bring the subgrade or
subbase to final grade and to a smooth dense
condition. Check the subgrade or subbase using
a multiple pin template operated on the forms or other methods approved by the
Engineer. Correct and retest all high or low spots.
Instead of the above
operation, the Contractor may place forms on subbase
or subgrade prepared according to 451.06.B.
B. Slip Form Construction. After the subgrade or base is placed and
compacted to the required density, use an automatic subgrading
machine to cut the areas for pavement and the areas that will support the
paving machine to the plan elevation. Construct the grade sufficiently in
advance of placing the concrete to permit the Engineer to check the grade.
451.07 Placing Concrete. When
constructing on subbase or subgrade, immediately
before placing concrete, bring the subgrade or subbase
to a thoroughly moistened condition by sprinkling with water at such times and
in such manner as directed by the Engineer.
When
constructing on asphalt concrete, coat the asphalt concrete with curing
membrane at least one day prior to placing concrete. Apply the curing
membrane at a minimum rate of 1 gallon (1 L) for each 150 square feet (3.7 m2)
of surface treated using an approved self-propelled mechanical sprayer.
Provide an adequate shield to protect the fog spray from the wind.
Thoroughly agitate the curing material before use.
Deposit
concrete on the grade in a manner that requires as little rehandling
as possible. Do not allow workers to walk in the freshly mixed concrete
unless wearing clean boots or shoes free of earth or any foreign material.
At
expansion and contraction joints, deposit concrete near the joints to ensure
the dowel basket assemblies are not disturbed. Do not allow concrete to
discharge onto any dowel basket assembly unless the hopper is well centered on
the assembly. Use a separate internal vibrator to consolidate concrete around
dowel basket assemblies.
Provided
the curing compound damage caused by sawing is repaired according to 451.11 and to the Engineer’s satisfaction, the
Contractor may operate the sawing equipment necessary to saw joints on the
newly constructed pavement. Do not operate other mechanical equipment
upon existing lane of pavement for seven days and specimen beams attain a
modulus of rupture of 600 psi (4.2 MPa). If
only finishing equipment is carried on an existing lane, paving may be
permitted after that lane has been in place for at least 3 days and after
specimen beams shall have attained a modulus of rupture of 500 psi (3.5 MPa).
When
the width of pavement being placed in one operation is 12 feet (3.6 m) or more
and the total area of any given width of pavement on the project exceeds 10,000
square yards (8300 m2), use a separate standard manufacture,
self-propelled concrete placer/spreader that receives concrete into a hopper
adjacent to the area to be paved and delivers the concrete in front of the slipform paver and uniformly spreads the concrete at the
proper thickness for the full width being paved. When a slipform paver is equipped with a dowel bar inserter the
separate placer/spreader requirement may be waived provided the concrete is
delivered in front of the slipform paver at a
consistent and uniform thickness for the full width being paved and the slipform paver is capable of spreading, consolidating, screeding, and float finishing the freshly placed concrete.
Provide the Engineer documentation that the slipform
paver will meet this specification.
Do
not mix, place, or finish concrete after dark without operating an adequate and
approved lighting system.
When
the air temperature is 35 °F (2 °C) or below, assure the concrete has a
temperature of between 50 and 80 °F (10 and 27 °C) at the point of placement.
When
the air temperature is greater than 35 °F (2 °C) before placing, maintain a
concrete temperature of not more than 95 °F (35 °C).
Do
not place concrete on any surface that is frozen or has frost.
Make
two test beams from each 7500 square yards (6300 m2) of concrete or
fraction thereof incorporated in the work each day.
451.08 Placing Reinforcement. Place
pavement mesh of the size and at the locations within the concrete slab shown
on the standard construction drawings. When placing reinforced concrete
pavement in two layers, strike off the entire width of the bottom layer to a
length and depth that allows laying the mat of reinforcement on the concrete
and in its final position without further manipulation. After installing
reinforcement directly upon the concrete, place, strike off, and screed the top
layer of concrete. When reinforced concrete pavement is placed in one
layer and in advance of placing concrete, position and securely anchor the
reinforcement to the underlying base or pavement. As an alternative,
after spreading the concrete and while it is in a plastic condition, use
mechanical or vibratory means to place reinforcement in the concrete.
Where
reinforcement is overlapped, securely fasten mats of reinforcement together at
the edges of the sheets and at two additional points along the lap. Use
reinforcing steel free from dirt, oil, paint, and grease.
451.09 Joints. Unless otherwise directed,
construct all transverse joints normal to the centerline of the pavement lane
and of the type, dimensions, and at locations specified.
Determine
contraction and longitudinal joint sawing time limits to protect the concrete
from early cracking by using HIPERPAV software. Obtain the software according
to Supplement 1033.
Twenty
four (24) hours before placing concrete pavement create a HIPERPAV project
date file according to Supplement 1033.
Provide
the completed file and the printout to the Engineer. When HIPERPAV predicts
early age slab cracking will occur, whether due to standard construction
practices, joint sawing methods, mix design or curing, either do not start
construction until modifications have been made to eliminate HIPERPAV’s predicted
slab cracking or do not pave.
Perform
a HIPERPAV analysis
for each pour.
If
software analysis determines joint sawing could exceed twenty four (24) hours,
assure all joints are sawed by the 24th hour.
A
HIPERPAV analysis
showing paving can proceed does not eliminate the
requirements of 451.17.
Accurately
mark the correct locations of all joints that will be saw cut along both edges
of the pavement. Ensure the method of marking remains clearly visible
after the paver passes and until the joint saw cut is completed.
A. Longitudinal Joint. Construct longitudinal joints between
simultaneously placed lanes by sawing.
When a standard
(water cooled diamond bladed) concrete saw is used to make the longitudinal
joint between simultaneously placed lanes, saw the joint within the timeframe
provided in the HIPERPAV
output. For pavement less than or equal to 10 inches (255 mm), saw
the joint to a minimum depth of one-fourth the specified pavement
thickness. For pavements greater than 10 inches (255 mm) thick, saw the
joint to a minimum depth of one-third the specified pavement thickness.
Saw joints 1/4 ± 1/16 inch (6 ± 1.6 mm) wide measured at the time of sawing.
When using
early-entry (dry cut, light weight) saws to make the longitudinal joint between
simultaneously placed lanes, only use saw blades and skid plates as recommended
by the saw manufacturer for the coarse aggregate type being used in the concrete.
Perform the early-entry sawing after initial set and before final set. Saw the
joint 1/8 inch (3 mm) wide and 2 1/4 to 2 1/2 inches (56 to 63 mm) deep.
Place deformed epoxy
coated steel tiebars or the epoxy coated hook bolt
alternate (wiggle bolt) with epoxy coated coupling, in longitudinal joints
during consolidation of the concrete. Install them at mid-depth in the
slab by approved mechanical equipment. As an alternate procedure, rigidly
secure them on chairs or other approved supports to prevent displacement.
Provide tie bars or wiggle bolts of the size and spaced as shown on the
standard construction drawings. If used, securely fasten hook bolts or
wiggle bolts with couplings to the form at the longitudinal construction joint
as shown on the standard construction drawings.
Unless otherwise
directed, construct all transverse joints normal to the centerline of the
pavement lane and of the type, dimensions, and at locations specified.
For all transverse joints,
install round, straight, smooth, steel dowel bars of the size shown in Table 451.09-1.
Thickness of Pavement (T) |
Diameter of Steel Dowel |
Less than 8 1/2 inches (215 mm) |
1 inch (25 mm) |
8 1/2 to 10 inches (215 to 255 mm) |
1 1/4 inches (32 mm) |
Over 10 inches (255 mm) |
1 1/2 inches (38 mm) or as shown on the plans |
Within
2 hours prior of placing concrete coat the full length of all dowels with a thin
uniform coat of new light form oil as a bond-breaking material.
Load Transfer Assemblies.
Use load transfer
(dowel basket) assemblies in transverse contraction joints conforming to and placed
according to the standard drawings to hold the dowels in a position parallel to
the surface and centerline of the slab at mid-depth of the slab thickness.
Preset all dowel
basket assemblies before the day’s paving unless the Engineer determines complete
presetting is impractical.
Completely install
dowel basket assemblies before shipping and spacer wires are
removed.
Immediately before
paving, remove all shipping and spacer wires from the dowel basket assemblies;
check the dowel basket assemblies are held firmly in place; check the dowels
are parallel to the grade and parallel to centerline of pavement.
For each joint
assembly used to hold dowels in position, provide a continuous assembly between
longitudinal joints or between the longitudinal joint and pavement edge.
Drive at least eight 1/2-inch (13 mm) diameter steel pins a minimum of 18
inches (460 mm) long at an angle to brace the assembly from lateral and
vertical displacements during the placing of concrete. Drive two of these
pins opposite each other at each end of the assembly, and drive the remaining
pins in staggered positions on each side of the assembly. Where it is
impractical to use the 18-inch (460 mm) length pins, such as where hardpan or
rock is encountered, and provided the assembly is held firmly, the Engineer may
authorize use of shorter pins. Where the dowel basket assembly is placed
on granular material that may allow settlement or distortion, anchor the
assembly with a combination of pins and steel plates, or by some other means
satisfactory to the Engineer to prevent settlement.
When
concrete pavement is placed on an existing concrete pavement or on a stabilized
base, secure dowel basket assemblies from lateral and vertical displacement
during concrete placement using power-driven fasteners and appropriate clips or
pins driven in predrilled holes of a diameter slightly less than the pin
diameter. Use either of the
above methods or a combination of the two in sufficient numbers to adequately
secure the basket assemblies.
Where widths other
than 12 feet (3.6 m) are specified, the Contractor may use standard dowel
basket assemblies with dowel spacings adjusted as
follows. Maintain 6-inch (150 mm) dowel spacing at the longitudinal joint
and increase the spacing at the outer edge of the lane up to 12 inches (300
mm). Where an odd width of lane occurs and if the standard dowel basket
assembly would provide for a space exceeding 12 inches (300 m), place a dowel 6
inches (150 mm) from the outer edge of the lane). Hold such a dowel
rigidly in proper position by a method satisfactory to the Engineer or cut and
splice a dowel basket assembly of greater length than required to attain the
required length.
Slip Form Paver with Mechanical Dowel Bar Inserter.
The Contractor may
propose to use a slip form paver with mechanical dowel bar inserter (DBI) to place dowels in transverse contraction joints the
full thickness of pavement and spaced per the requirements of the standard
construction drawings. Submit details and specifications of the proposed
equipment to the Engineer at least 14 calendar days prior to mobilizing the
equipment to the project.
The use of any slip
form paver with DBI is allowed only after acceptable
performance is demonstrated with a test section and approved by the
Engineer. Continued verification during all contract paving is required
for each production day as detailed below.
Provide all
equipment, perform all testing, and evaluate the slip form paver with DBI as detailed in the following sections.
1.
MIT Scan-2 Equipment and Reporting
Provide MIT Scan-2 equipment to
determine the location of dowel bars in either fresh or hardened concrete
including horizontal and vertical alignment, side shift, depth, and horizontal
translation.
Provide equipment for
determining dowel bar alignment that has an onboard computer that runs the
test; collects and stores the test data on a memory card; performs the
preliminary evaluation; and provides a printout of results immediately after
scanning. Provide MagnoProof software to provide a detailed report of all
required alignment parameters in an Excel spreadsheet and a graphical color
representation.
Ensure the equipment
is properly calibrated per the manufacturer’s specifications. Establish a
standard protocol for scanning direction.
Provide trained
personnel to operate the equipment.
Provide a print out,
at the time of scanning, for horizontal translation, longitudinal translation,
depth, horizontal rotation and vertical rotation
for each bar in each joint. Provide a complete report to the Engineer at
the completion of scanning with all data provided in the manufacturer’s native
file format as well as all calibration files. Include the standard report
generated using the MagnoProof software in Excel format and with color
graphical representation of each joint. Include in the report project
contract number, county-route-section, placement date, scan date, station
location and lane, joint ID number, name of operator, and all required
alignment parameters.
The required dowel
bar tolerances are given in Table 451.09-2.
Dowel bar alignment is measured as detailed below. Any dowel bar
exceeding any Acceptance Tolerance in Table 451.09-2
is considered misaligned. Rejection Criteria is in absolute inches.
Dowel Bar Tolerances
Alignment
Parameter |
Acceptance
Tolerance (inches) |
Rejection
Criteria (inches) |
Horizontal
Translation a |
±0.50 |
±2 |
Longitudinal
Translation b |
±2.0 |
±2.30 |
Depth
Translation c |
±0.50 |
±0.66 |
Horizontal
Rotation d |
±0.50 |
±0.70 |
Vertical
Rotation e |
±0.50 |
±0.70 |
a. Horizontal Translation - the total
difference, measured horizontally, between the actual dowel bar location and the plan required dowel bar location along the
transverse contraction joint.
b. Longitudinal Translation - the total
difference, measured in the longitudinal direction, from the center of the
transverse contraction joint to the actual dowel bar center. Also
termed as “side shift”.
c. Depth - the total difference, measured
vertically, between the actual dowel bar location and the mid-depth of the
slab.
d. Horizontal Rotation - the total
difference, measured from end to end of a dowel bar, of the dowel in the
horizontal plane.
e. Vertical Rotation
- the total difference, measured from end to end of a dowel bar, of the
dowel bar in the vertical plane.
Horizontal
Translation |
Longitudinal Translation |
Depth |
Horizontal Rotation |
Vertical Rotation |
Perform a Joint Score
Analysis per CPTP Tech Brief Best Practices for Dowel
Placement Tolerances (FHWA-HIF-07-021)
for every joint. Joint Score is a measure of the combined effects of
rotational misalignment. Calculate the Joint Score: determine the square
root of the sum of the squares of the Horizontal Rotation and Vertical Rotation
of each dowel in the joint; assign a Weight for each misalignment category for
each bar; sum the product of the Weight and the number of bars in each
misalignment category and add 1.
Include the Joint
Score for every joint scanned in the report to the Engineer.
Prior to production
use, perform a minimum 500-feet test section when using a slip form paver with DBI for acceptance of the machine. Evaluate all
joints (all bars in each joint) for required dowel alignment using the MIT Scan-2. Do not
place additional pavement until the slip form paver is accepted for use on the
project.
a. Evaluation and Acceptance
The slip form paver and DBI can be accepted
by the Engineer if one of the following requirements is met.
Ninety-Five (95%) of the
dowels in every test section are within the Acceptance Tolerances.
Each Joint Score is less
than 10, and there is no Horizontal Rotation or Vertical Rotation greater than
the Rejection Criteria, and the Longitudinal Translation and Depth all of bars
are within the Acceptance Tolerances.
Reject any slip form
paver and DBI not meeting the above requirements.
Repair or replace any rejected slip form paver and DBI
and repeat the test section.
Perform corrective
action of all joints in the test section as per Section
5 below.
Perform the test
strip for any new slip form paver and DBI that will
be used for any contract item of work. New test strips are required at
the beginning of every construction season; after major paver
maintenance/repairs; at mobilization and remobilization to a project, after
major concrete mix design changes; and as required by Section 4 of this
specification.
When using the
accepted slip form paver and DBI for any contract
item of work, scan 10% of all joints (all dowels in the joint), randomly selected
by the Engineer. Run additional scans as needed. Perform scanning,
calculate the Joint Score, and submit the completed report to the Engineer
within 24 hours of each day’s production. The Engineer may accept an
initial report to determine whether paving can continue.
Continue paving ONLY
if one of the following requirements is met:
All Joint Scores are less
than 10 and all other alignment parameters are less than the Rejection
Criteria.
Isolated Joint Scores
greater than 10 are allowed if dowel bar Longitudinal Translation and Depth are
less than the Rejection Criteria and there are three (3) joints ahead and
behind the joint with Joint Scores of less than 10 (with Longitudinal
Translation and Depth less than the Rejection Criteria).
Discontinue paving,
repair or replace the slip form paver and DBI, and
repeat the Test Section when the above requirements are not met.
Investigate and fix
any accepted slip form paver with DBI that exhibits
systematic misaligned dowel bar installations.
The following
conditions require removal and replacement per SCD
BP-2.5:
Any Joint Score greater
than 10 that does not meet the above criteria for continuing paving.
Any joint
where the dowel Longitudinal Translation is greater than the Rejection Criteria
in the first 4 dowels from a longitudinal joint.
Any joint
where the dowel Depth deviation is greater than the Rejection Criteria in the
first 4 dowels from a longitudinal joint.
Any joint
where the dowel Horizontal deviation is greater than the Rejection Criteria in
the first 4 dowels from a longitudinal joint.
C. Expansion Joints. Where a pressure relief joint is not provided adjacent
to a bridge structure, construct expansion joints at the first two regularly
spaced joint locations adjacent to the bridge approach slab on each side of the
bridge. If the pavement is constructed in two or more separately placed
lanes, construct the transverse expansion joints in a continuous line for the
full width of the pavement and shoulders.
Construct expansion
joints according to the standard construction drawings. Install the face
of the expansion joint perpendicular to the concrete surface except when
expansion joint is installed at a skewed bridge approach slab.
Use round, straight,
smooth, steel dowels, and within 2 hours of placing
concrete, coat the dowels with a thin uniform coat of new light form oil as a
bond-breaking material to provide free movement. After coating the dowel,
install a sleeve of metal or other approved material approximately 3 inches (75
mm) long, with crimped end, overlapping seams fitting
closely around the dowel, and a depression or interior projection to stop the
dowel a sufficient distance from the crimped end to allow 1 inch (25 mm) for
longitudinal dowel movement with pavement expansion on one free end of each
dowel. If approved by the Engineer, use other means to allow for 1 inch
(25 mm) of expansion.
Punch or drill proper
size dowel holes into the preformed expansion joint filler to assure a tight
fit around each dowel.
Form a 1-inch (25 mm)
wide and 1-inch (25 mm) deep opening on top of the expansion joint filler and
seal this opening with 705.04 joint sealers.
D. Contraction Joints. For pavement less than or equal to 10 inches (225 mm)
thick, saw contraction joints with a standard (water cooled diamond bladed)
concrete saw to a minimum depth of one-fourth of the specified pavement
thickness. For pavement greater than 10-inches (255 mm) thick, saw
contraction joints to a minimum depth of one-third the specified pavement
thickness. When cutting joints using a standard (water cooled diamond
blade) saw assure the joint is 1/4 ± 1/16-inch (6 ± 1.6 mm) wide when measured
at the time of sawing.
When using the option
of early-entry (dry cut, light weight) saws, only use saw blades and skid
plates as recommended by the saw manufacturer for the coarse aggregate type
being used in the concrete. Perform the early entry contraction joint sawing
after initial set and before final set. Saw the contraction joint 2-1/4 to
2-1/2-inches (56 to 63 mm) deep. Ensure any early entry saw joints are
approximately 1/8-inch (3 mm) wide at the time of sawing.
If the pavement is constructed
in two or more separately placed lanes, install the joints continuous for the
full width of the pavement. Saw the pavement with sawing equipment
approved by the Engineer as soon as the saw can be operated without damaging
the concrete. Provide saws with adequate guides, blade guards, and a
method of controlling the depth of cut. After wet sawing, clean the joint
using a jet of water. After dry sawing clean the joint using air under
pressure. During sawing of contraction joints, maintain a standby saw in
working condition with an adequate supply of blades.
E. Construction Joints. Install dowelled construction joints at the end
of each day’s work and when work is suspended for a period of more than 30
minutes.
Use dowels in
transverse construction joints. Within 2 hours of placing concrete, coat
the free half of all dowels with a thin uniform coat of new light form
oil. Use an adequate bulkhead, with openings provided for dowel bars
spaced as specified and shaped to fit the typical section of the pavement, to
form a straight joint. During placing of concrete, hold dowels rigidly in
position.
Locate construction
joints at or between contraction joints. If located between contraction
joints, construct the construction joint no closer than 10 feet (3 m) to the
last contraction joint.
451.10 Finishing. Use 10-foot (3 m) straightedges
to continually check the finished concrete surface for trueness. If the
pavement surface is dragged with a diagonal pipe float machine, occasionally
check the surface while the concrete is plastic. Do not add water to aid
finishing.
Before
the concrete initially sets, round the edges of the pavement along each side of
each slab and on each side of transverse expansion joints to the radius
specified using an approved edging tool. Before texturing the surface,
eliminate tool marks left by the edging tool.
Texture
the surface in the longitudinal or transverse direction using a broom to
produce a uniform, gritty, texture. Immediately following the broom drag
texture, tine the pavement in the longitudinal direction using an approved
device that produces uniform tine spacing 3/4-inch wide (19 mm), 1/8-inch deep
(3 mm) and 1/8-inch wide (3 mm). Do not tine within 3 inches (75 mm) of
pavement edges or longitudinal joints. Only use equipment that will tine
the full width of the pavement in one operation and uses string line controls
for line and grade to ensure straight tining texture.
Use
transverse tining in small areas only with the
approval of the Engineer. Use equipment that produces a random pattern of
grooves, 0.05 to 0.08-inch (1.3 to 2.0 mm) deep and 0.10-inch (3 mm) wide,
spaced at 3/8 to 1-3/4 inches (10 to 45 mm), with 50 percent of spacings less than 1 inch (25 mm).
Demonstrate
to the Engineer methods to assure the groove depth meets this specification.
Before
the concrete finally sets, impress complete station numbers into the pavement
every 100 feet (50 m), e.g., 1+00 (2+050). Mark station equations in the
pavement as shown on the plans. Ensure that the numerals are 3 to 4
inches (75 to 100 mm) high and 1/4 inch (6 mm) deep. Place the station
numbers parallel with and facing the right edge of the pavement, and centered
12 inches (0.30 m) in from the right edge. On divided highways, provide
station numbers on both pavements. When placing concrete shoulders with
the traveled lane, place station numbers 12 inches (0.30 m) in from the outside
edge of the shoulder and facing the pavement.
451.11 Curing. Immediately after the finishing
operations have been completed and after all free water has dissipated, spray
and seal all exposed concrete surfaces with a uniform application of curing
membrane in such a manner as to provide a continuous uniform film without
marring the surface of the concrete. Apply a minimum of 1 gallon (1 L) of
material for each 150 square feet (3.7 m2) of surface treated using
an approved self-propelled mechanical sprayer. Provide an adequate shield
to protect the fog spray from the wind. Before each use, thoroughly
agitate the curing material.
On
pavement with integral curb or small and irregular areas that are inaccessible
to the mechanical spray machine, apply the curing material by a hand-held
sprayer.
As
soon as the forms have been removed, immediately correct all honey-comb areas
and coat the edges of the pavement with the curing material.
Respray all areas of
curing material film damaged during the sawing of joints.
The
Contractor may water cure concrete with wet burlap cloth, waterproof paper, or
polyethylene sheeting. Apply curing as soon as possible and without
marring the concrete surface. Unless the specimen beams have attained a
modulus of rupture of 600 psi (4.2 MPa) keep the
entire surface of the top and sides of the newly placed concrete covered for
seven days. Protect concrete from freezing until beams attain a strength of 600 psi (4.2 MPa).
The
above requirements for curing are minimum requirements only. Repair or
replace all concrete showing injury or damage due to noncompliance to curing
requirements at no additional cost to the Department.
451.12 Removing Forms. Remove forms in a manner
that doesn’t damage the pavement.
451.13 Surface Smoothness. After
final concrete curing and cleaning the pavement surface, test the pavement
surface for smoothness using a 10-foot (3 m) rolling straightedge.
Provide a two or four-wheeled device 10 feet (3 m) in length with an indicator
wheel at the center which detects high and low areas in the pavement
surface. Provide equipment which actuates a pointer scale, an audio
alert, or marks the pavement with paint or dye when encountering any high or
low areas in excess of a preset tolerance. Tow the 10-foot (3 m) rolling
straightedge or walk the equipment over the completed pavement. Test all
wheel paths in the presence of the Engineer. Locate wheel paths parallel
to the pavement centerline and approximately 3 feet (1 m) measured transversely
inside all lane edges. Maintain alignment of the 10-foot (3 m) rolling
straightedge with reference to the pavement edge at all times. Other
devices such as approved profilers conforming to S1058
and using ProVAL
software may be used with approval of the Engineer.
Correct
all surface variations so indicated to within the specified tolerance and in a
manner that provides a surface texture conforming to 451.10.
For corrective grinding provide equipment conforming to 451.14. Ensure pavement surface variations do
not exceed 1/8 inch in a 10-foot (3 mm in a 3 m) length of pavement. For
ramp pavements and for those pavements with curvature greater than 8 degrees,
or with grades exceeding 6 percent, ensure the surface variations do not exceed
1/4 inch in 10 feet (6 mm in 3 m).
Repair
or replace sections of pavement containing depressions that cannot be corrected
by grinding as directed by the Engineer.
451.14 Profile Grinding. To
correct surface variations exceeding tolerances specified in 451.13 use grinding equipment conforming to Item 257.
451.15 Pavement Grooving Corrections. When
pavement tining locations are found out of
conformance with 451.10 restore the tining using power driven, self-propelled machines
specifically designed to groove concrete pavement with diamond impregnated
blades or diamond impregnated cylinder rings. Furnish blades or cylinder
rings mounted on an arbor head so that the resulting grooves comply with 451.10. Furnish grooving equipment with a
depth control device that will detect variations in the pavement surface and
enable adjustment of the cutting head to maintain the specified groove
depth.
If
a pavement area was diamond ground to bring the pavement’s surface smoothness
within the tolerances of 451.13, that pavement
area does not require tining restoration conforming
to 451.10.
Vary
from these requirements only for small areas and only with written permission
from the Engineer.
451.16 Sealing Expansion Joints. As soon
as feasible after completing sawing, but before the pavement is open to
construction equipment and traffic, seal expansion joints with material
conforming to 705.04. Just before
sealing, thoroughly clean each joint of all foreign material, using approved
equipment. Ensure the joint faces are clean and dry when the seal is
installed.
451.17 Opening to Traffic. When 7
days have elapsed, the Contractor may use the completed pavement for traffic,
including construction traffic. If a modulus of rupture of 600 psi (4.2 MPa) has been attained, the Contractor may open the
pavement to traffic when 5 days have elapsed. If necessary to open a
portion of the pavement in less than 5 days, with the proviso that the pavement
will be cured for a minimum of 3 days, use a high early strength concrete
composed of additional 701.04 or 701.05 cement, or non-chloride accelerating
admixture to obtain a modulus of rupture of 600 psi (4.2 MPa)
in 3 days or less.
Pavement Repairs before Department
Acceptance.
Repair
diagonally cracked full depth pavement; longitudinally cracked full depth
pavement; spalled pavement surfaces and any Portland
cement concrete pavement panels with cement balls or mud balls; at no cost to
the Department. Repair transverse cracks except do not repair a single
hairline transverse crack in the middle third of panels with reinforcing
conforming to BP1.1.
Repair transverse or diagonally cracked PCC
pavement with a full depth repair according to Item
255 and applicable standard construction drawings. Repair cracks by
replacing the pavement the full width between longitudinal joints,
perpendicular to the centerline and at least 6 feet (1.8 m)
longitudinally. Install smooth dowel bars at the interface between the
original pavement and the replaced pavement section. Locate and size the
repairs to ensure that the repair limits are at least 7 feet (2.1 m) away from
any transverse joint.
Repair longitudinal cracks within 15 inches (380 mm) of a tied
longitudinal joint by routing and sealing the crack according to Item 423. For other longitudinal cracks, repair
the same as for transverse or diagonal cracks stated above.
Repair spalled pavement with Item 256 Bonded Patching of
Portland Cement Concrete Pavement.
Repair cement balls or mud balls by coring out the area, full depth,
with a diamond core bit and replacing the removed concrete with the same
concrete as in the pavement. Remove and replace any pavement panel with 5
or more cement balls or mudballs. Locate the
limits of the repair along the longitudinal joints and at least 1-foot (0.3 m)
past the transverse joints to remove any existing dowel bars. Install
smooth dowel bars at the transverse limits of the repairs. Install Type D
(Drilled Tied Longitudinal) Joint along the longitudinal limits.
451.18
Pavement
Thickness and Concrete Strength.
A.
Thickness. As determined
by measurement of cores cut as specified in this section, construct the
concrete not more than 0.2 inch (5 mm) less than the specified thickness.
Core pavement at the direction of the Engineer and at locations the Engineer
determines according to Supplement 1064.
For the purpose of
coring, the Department will consider the entire pavement area of a specified
thickness a lot. To determine the number of cores, each pavement lot will
be divided into sublots. A sublot
consists of 2000 yd2 (1650 m2) of a pavement lot or major fraction thereof.
Take one random core
for each sublot but not less than 3 cores for any
pavement lot cored. If a core shows a deficiency in thickness of more
than 1/2 inch (13 mm) from the specified thickness take additional cores to
determine the limits of the deficiency. Follow the procedures below:
1.
Take a core five (5) feet (1.5 m) longitudinally on both sides of the deficient
core. If both the cores are less than 1/2-inch (13 mm) deficient in
thickness the zone of deficiency has been determined.
2.
If either or both 451.18.A.1 cores are more than 1/2 inch (13 mm) deficient in
thickness, cut a core 50 feet (15 m) longitudinally from the deficient
core(s). If the 50 foot (15 m) core(s) is more than 1/2 inch (13
mm) deficient, cut additional cores at 100 foot (30 m) longitudinal intervals
until a core is less than 1/2 inch (13 mm) deficient; until the pavement ends;
or until overlapping an adjacent pavement sublot’s
core in the same lane.
3.
If a pavement sublot has cores more than 1/2 inch (13
mm) deficient in thickness and the sublot’s constructed width is greater than 12 feet (3.6 m)
obtain cores transverse to the location of the deficient cores. Obtain
transverse cores at a location 1/2 the distance from the deficient core to the
furthest edge of pavement. Obtain a transverse core for each core more
than 1/2 inch (13 mm) deficient.
4.
The Engineer will use the cores that measure less than 1/2 inch (13 mm)
deficient in thickness to define the limits of the deficiency.
If any deficient core
is greater than 1 inch (25 mm) deficient in thickness determine the limits of
over 1 inch (25 mm) deficiency by following 451.18.A.1
thru 4 to determine the limits. Remove and replace those areas greater
than 1 inch (25 mm) deficient in thickness.
The Engineer will
calculate average thickness of concrete pavement placed as follows:
When zones of
deficient thickness greater than 1/2 inch (13 mm) to 1 inch (25 mm) are allowed
to remain in place, the Engineer will calculate two average thicknesses.
A Project Average Thickness (PAT) including all cores not more than 1/2 inch
(13 mm) deficient. Cores that exceed the specified thickness by more than
½ inch (13 mm) will be considered as the specified thickness plus 1/2 inch (13
mm) when calculating the PAT. A second Deficient Zone Average (DZA) will include all cores with thickness deficiency
greater than 1/2 inch (13 mm) to 1 inch (25 mm). The pavement represented
by each of the two averages, PAT or DZA, will be calculated
and paid separately.
The Engineer will
determine and apply deductions to each separately placed width of pavement.
For any pavement
areas removed and replaced, re-core those areas replaced following this section
of the specifications. Include those core values into the calculations
for average pavement thickness.
Unless the Director
requests, do not core any widening less than 5 feet (1.5 m) in width or any
pavement area less than 2000 square yards (1650 square meters).
Fill all core holes
with concrete of the same proportions and materials used in the pavement.
B. Strength. Obtain an additional core at the same location
as the thickness core from each pavement sublot to
determine compressive strength. .
For
concrete pavement bid items “with QC/QA”, the AMRL
accredited laboratory will test the QC cores for compressive strength according
to ASTM C 42. Test the QC cores from 28 to 90 days of
age. Notify the Engineer when the QC cores will be tested.
The Engineer will
require one QA core for every 10 sublots for
verification testing of compressive strength. Obtain the QA core from the
same location as the QC core tested for compressive strength. At least
one QA core will be required per lot. Provide the QA cores to the Engineer for
testing at the Department’s laboratory. Notify the Engineer of the date
that the corresponding QC core will be tested. The QA cores will be
tested on the same date. The Engineer will verify the QC cores versus the
QA cores according to 455.
Calculate an average
and standard deviation for each lot according to Supplement
1127. Determine the pay factors according to Table 451.19-2.
Do not calculate an
average and standard deviation for high-early strength concrete QC cores.
Determine the pay factors for individual sublots
according to Table 451.19-2.
For
concrete pavements bid items “without QC/QA”, the Department will perform the
strength testing. Provide
the Engineer with the cores for strength
testing. Pay factors for sublot cores will be
calculated based on the high-early strength concrete pay factors in Table 451.19-2.
451.19
Price Adjustments. Payment will be made at the unit bid price upon
completion of any section of pavement. Final pay adjustments to the bid
price will be made upon completion of the pavement operations and all
thickness, strength and smoothness data is tabulated and pay adjustments
applied per 451.19.A thru 451.19.D.
A. Pavement Thickness. Price
adjustments for thickness deficiencies will be calculated according to the Table 451.19-1
Concrete
Pavement THICKNESS PAY FACTOR (pft) |
|
Deficiency in Thickness as Determined by Cores |
Proportional Part of Contract Price |
0.0
to 0.2 inch (0.0 to 5 mm) |
100 percent |
0.3
to 0.5 inch (6 to 13 mm) |
|
0.6
to 1.0 inch (15 to 25 mm)* |
|
Greater
than 1.0 inch (25 mm) |
Remove and replace |
* The District Construction Engineer will
determine whether pavement areas from 0.6 inch (15 mm) up to 1 inch (25 mm)
deficient in thickness will be allowed to remain in place at the reduced price
or must be removed and replaced.
PAT = Project Average
Thickness
PST = Plan
Specified Thickness
DZA = Deficient Zone Average
B. Concrete Strength.
Record the compressive strength results for each sublot
of concrete. High-early strength mixes, QC MS and QC FS,
mixes, are calculated separately. Determine the strength pay factor
according to Table 451.19-2.
CONCRETE PAVEMENT STRENGTH PAY FACTOR |
|
C. Pavement
Smoothness. When the Project
plans include Proposal
Note 420 determine a lump sum payment adjustment following the requirements
of Proposal
Note 420.
D. Multiple Deficiencies. When
a pavement exhibits multiple deficiencies for thickness and strength, the
reduced unit price will be calculated for each deficiency and the lowest
reduced unit price will be used. Adjustment for smoothness under 451.19.C will conform to the lump sum
requirements of 451.19.C.
451.20 Method of Measurement. The
Department will measure Reinforced Concrete Pavement by the number of square
yards (square meters) completed and accepted in place. The width equals
the pavement width shown on the typical cross-section of the plans plus
additional widening as the Engineer directs in writing. The Department
will field measure the length along the centerline of each roadway or
ramp. The Department will determine the area based on the above width and
length.
451.21 Basis of Payment. Payment
is full compensation for furnishing and placing all materials including
reinforcing steel, dowels, and joint materials; for furnishing the 10-foot (3
m) rolling straightedge; and for coring and testing the pavement. For
pavement found deficient in thickness or compressive strength, the Department
will pay a reduced price according to 451.19.
The Department
will not pay extra for pavement with an average thickness in excess of that
shown on the plans.
The Department
will pay for accepted quantities at the contract price as follows:
Item
Unit
Description
451
Square
Yard
Reinforced Concrete Pavement
(Square
Meter)
451
Square
Yard
Reinforced Concrete Pavement with QC/QA
(Square
Meter)
451
Square
Yard
Reinforced Concrete Pavement Class
(Square
Meter)
451
Square
Yard
Reinforced Concrete Pavement Class with QC/QA
(Square
Meter)