item 401 Asphalt Concrete
PAVEMENTS—GENERAL
401.01
Description
401.02 Mix
Design and Quality Control
401.03
Materials
401.04
Reclaimed Asphalt Concrete Pavement and Reclaimed Asphalt Shingles
401.05 Mixing
Plants
401.06 Weather
Limitations
401.07
Notification
401.08 Asphalt
Binder
401.09
Aggregate Preparation
401.10 Mixing
401.11 Hauling
401.12
Spreading Equipment
401.13 Rollers
401.14
Conditioning Existing Surface
401.15
Spreading, Finishing and Night Work
401.16
Compaction
401.17 Joints
401.18 Asphalt
Binder Compatibility
401.19
Spreading and Surface Tolerances
401.20 Asphalt
Binder Price Adjustment
401.21 Method
of Measurement
401.22 Basis of
Payment
401.01 Description. This specification is
applicable to all types of asphalt concrete pavements irrespective of gradation
of aggregate, kind, and amount of asphalt binder, or pavement use.
Deviations from these general requirements are covered in the specific
requirements for each type according to the appropriate contract item or items.
Work
consists of one or more courses of asphalt concrete constructed on a prepared
foundation. The asphalt concrete consists of a mixture of uniformly
graded aggregate and specified type and grade of asphalt binder.
Control
all production processes to assure the Engineer that the mixture delivered to
the paving site is uniform in composition, conforms to the specification
requirements and that the placed mixture is free of any defect (ex. segregation, tenderness, lack of mixture and texture
uniformity, raveling, flushing, rutting, holes, debris etc.) within
the Contractor’s control at project completion.
The
asphalt concrete pavement thickness shown on the plans or stated in the
Proposal is for the exclusive use in calculating the weight required to be
placed per unit of surface area.
401.02 Mix Design and Quality Control. Use an approved
Job Mix Formula (JMF). The quality control and acceptance
requirements of Item 403 apply unless otherwise
specified.
If
required to perform the mix design or quality control, provide a laboratory and
personnel meeting the requirements of Supplement
1041 to perform mix design and quality control tests.
Calibrate
asphalt content nuclear gauges according to Supplement
1043 using personnel with a minimum Level 2 rating according to Supplement
1041. Mix and test the calibration verification sample with a
Department employee present.
Provide
and dispose of the solvent used for cleaning the asphalt content nuclear gauge
pans.
401.03 Materials. Furnish materials conforming to:
Asphalt binder
.... (asphalt concrete, 401.14, 401.15)......................
702.01
Asphalt material (401.14,
401.18)......................................
.............................................. 702.01,
702.04, or 702.13
Aggregates (base
courses)....................................... 703.04
Aggregates (intermediate
and
.... surface
courses).................................................. 703.05
Mineral filler
........................................................... 703.07
Sample aggregate, asphalt binder,
asphalt material, and mineral filler according to 106.01.
If
100 percent of coarse aggregate in an asphalt mix design is steel slag, the
Contractor may include steel slag as a maximum of up to 50 percent of fine
aggregate. If a steel slag source causes bulking (expansion resulting in
flushing or material loss) in asphalt concrete courses, the Laboratory will
place limits on the amount of steel slag allowed in a mix design. Bulking
may occur when a large percentage of an asphalt mix design is steel slag aggregate.
Bulking may be shown through testing, such as ASTM D 4792, or through
field failure such as, but not limited to, flushing on newer pavement or
apparent over-asphalting in production. The Department may require the
steel slag processor at any time to perform additional testing to verify steel
slag properties. Potential pavement performance problems due to poor
control of steel slag aggregate include bulking, poor gradation and specific
gravity control resulting in highly variable void properties, excess soft
pieces resulting in pock marks, flushing, etc.
Take
prompt corrective action if mixture delivered to the paving site is not uniform
in composition, does not conform to the specification requirements or is not
free of any defect (ex. segregation, tenderness,
lack of mixture and texture uniformity, raveling, flushing, rutting, holes,
debris etc.) within the Contractor’s control as
determined by the Engineer. The Engineer will stop conditional acceptance
of the asphalt concrete for failure to correct problems.
401.04 Reclaimed Asphalt Concrete Pavement and Reclaimed
Asphalt Shingles.
Provide reclaimed asphalt concrete pavement (RAP) and/or reclaimed asphalt
shingles (RAS) according to the following requirements when choosing to use the
in a mix. Failure to follow these requirements will result in a rejection
of the Contractor QCP (403.03);
restriction of any RAP or RAS use at the facility; and/or a change to
Unconditional Acceptance at the facility.
Job Mix Formula. The Contractor
may use a blend of new materials in combination with RAP obtained from
verifiable Department or Ohio Turnpike Commission projects and/or RAS obtained from
un-used manufactured shingle waste or used roofing tear-off shingles as listed
in Tables 401.04-1 and 401.04-2 and as follows. If the RAP is not
from the above sources or the source is unknown, process and blend the RAP into
a single uniform stockpile, test according to Level 3 Asphalt Mix Design
requirements and obtain District approval for use. Obtain written Laboratory
approval for use of unusually large, old RAP stockpiles of unknown content
and/or age. Include approved methods in the QCP
for ongoing processing and testing of these piles. Ensure no foreign or
deleterious material (703.04, 703.05) is present in RAP. All RAS
suppliers must meet the requirements of Supplemental Specification
1116.
Ensure
that the JMF falls within the specified limits of the
required mix item. Ensure the JMF submittal includes
the percentages of RAP, RAS, virgin aggregates, and virgin asphalt binder
required for the mix item. Report all RAP and RAS test results, including
binder blend analysis, in the JMF submittal.
Identify the RAP in the JMF submittal as to project
origin and mix type(s). Identify the manufactured shingle waste manufacturer
source or the approved tear-off RAS processor in the JMF
submittal.
Determine
RAP properties and uniformity as follows. Determine the final RAP
gradation and asphalt binder content on a minimum of four separate stockpile
(or roadway for concurrent grinding) samples all agreeing within a range of 0.4
percent for asphalt binder content and 5 percent passing the No. 4 (4.75 mm)
sieve. If fractionated RAP is used use a suitable sieve for determining
gradation uniformity.
Determine
RAS properties and usage as follows. Use no more than 5.0 percent RAS by
dry weight of mix. For design assume 18.0 percent available RAS binder.
Determine gradation and specific gravity according to AASHTO PP 53-09, Section 5 or subsequent AASHTO
applicable standard. Provide the required certification forms in the JMF submittal documenting that the RAS meets AASHTO MP 15-09, sections 3.2 or 3.3 and that RAS from
roofing tearoffs conforms to the EPA’s NESHAP, 40
CFR 61 Subpart M, and other applicable agency
requirements for asbestos.
RAP and RAS Usage Limits and
Requirements.
Process and use RAP and RAS as follows.
Process
and use RAP by one of the following two methods. Note on the JMF submittal RAP page which of Method 1 or Method 2
methods described below apply to the RAP.
1. Method 1 Standard RAP. Include RAP in a JMF
submittal according to the Standard RAP/RAS Limits Table
401.04-1 unless specified differently in the applicable mix
specification. For mixes that will contain up to 10 percent RAP the JMF submittal is not required to include the RAP except
when a virgin polymer asphalt binder is used in a surface course. For
surface course JMFs having polymer asphalt binder
only submit at 0 or 10 percent RAP. If greater than 20
percent RAP is used in a JMF submittal include an
analysis of the recovered asphalt binder and blend according to Level 3 Mix
Design procedures to determine the grade of virgin asphalt binder to use.
TABLE
401.04-1 Method 1 – Standard RAP/RAS Limits
Asphalt Mix Application |
Percent RAP by Dry Weight of Mix Max. |
RAS Usage [1] |
Total Virgin Asphalt Binder
Content, Min. |
Comments |
Heavy Traffic Polymer Surface Course |
10% |
None |
5.2 |
Polymerized binder is virgin. (For non-polymer virgin binder
allow 20% max RAP and 5.0 min. virgin.) |
Medium Traffic Surface Course |
20% |
Manufacturing waste only |
5.0 |
Polymer or non-polymer virgin. |
Light Traffic Surface Course |
20% |
Manufacturing waste only |
5.2 |
Polymer or non-polymer virgin. |
Intermediate Course |
35% |
Manufacturing waste and tear-offs |
3.0 |
Any mix type used as an intermediate course. |
Base Course 301 |
50% |
Manufacturing waste and tear-offs |
2.7 |
The Laboratory will establish the asphalt binder content. |
Base Course 302 |
40% (30%) |
Manufacturing waste and tear-offs |
2.0 |
A lower RAP limit of 30 percent will be required if poor
production mixing or coating is evident. |
[1]
No more than 5.0% RAS by dry weight of mix
RAP
Processing for Table 401.04-1 Method 1-Standard RAP. For
surface courses process RAP to less than 0.75 inch (19 mm) and place a 0.75
inch (19 mm) screen on the cold feed. For other courses place a 2-inch
(50 mm) screen on the cold feed. Ensure that the RAP is the proper size
to allow for complete breakdown in the plant. If mixing is incomplete,
place a smaller screen on the cold feed.
2. Method 2 Extended RAP. Include RAP in a JMF
submittal according to the Extended RAP/RAS Limits Table
401.04-2 unless specified differently in the applicable mix
specification. Only use Method 2 with counter flow drum plants or
mini-drum batch plant configurations meeting 402.
For mixes that will contain up to 15 percent RAP the JMF
submittal is not required to include the RAP unless a virgin polymer asphalt
binder is used in a surface course. For JMFs
having polymer asphalt binder do not submit at 1 through 9 percent RAP.
If greater than 25
percent RAP is used in a JMF submittal include an
analysis of the recovered asphalt binder and blend according to Level 3 Mix
Design procedures to determine the grade of virgin asphalt binder to use.
If the blending shows a grade change is required use a PG64-28 for heavy intermediate
courses or PG 58-28 or 64-28 for medium intermediate or base courses. No
grade change is required with RAP at 26 to 40 percent if Warm Mix Asphalt (WMA)
technology is used in a manner to maintain the mix temperature below 275 °F
(135 °C). Use WMA technology meeting 402.04.
Other WMA technologies must be approved by the Laboratory. If desired, WMA may
be used to control plant temperatures when producing mixes using RAP above 40
percent, but a grade change is required if shown necessary by the blending index.
TABLE
401.04-2 Method 2-Extended RAP/RAS Limits
Asphalt Mix Application |
Percent RAP by Dry Weight of Mix Max. |
RAS Usage [1] |
Total Virgin Asphalt Binder
Content, min. |
Comments |
Heavy Traffic Polymer Surface Course |
15% |
None |
5.0 |
Polymerized binder is virgin. (For non-polymer virgin
binder allow 25% max RAP and 4.6 min virgin.) |
Medium Traffic Surface Course |
25% |
Manufacturing waste only |
4.8 |
Polymer or non-polymer virgin. |
Light Traffic Surface Course |
25% |
Manufacturing waste only |
5.0 |
Polymer or non-polymer virgin. |
Intermediate Course |
40% |
Manufacturing waste and tear-offs |
3.0 |
Any mix type used as an intermediate course. |
Base Course 301 |
55% |
Manufacturing waste and tear-offs |
2.5 |
The Laboratory will establish the asphalt binder content. |
Base Course 302 |
45% (35%) |
Manufacturing waste and tear-offs |
1.8 |
A lower limit of 35 percent will be required if poor
coating is evident. The virgin requirement of 302.02 does not apply. |
[1]
No more than 5.0% RAS by dry weight of mix
RAP
Processing for Table 401.04-2 Method 2-Extended RAP. Process
RAP by means of fractionation or by additional in line processing.
Include in the QCP additional methods and procedures
to dictate how this is to be accomplished at plants. Specify
documentation method for RAP measurement. Fractionation is the process of
creating separate piles of RAP from one pile when split over a specific sieve
or sieves. Test fractionated piles to show uniformity. For
additional in line processing only process RAP from a uniform, tested and
approved stockpile by passing the RAP over a double deck screen placed in-line
between the RAP cold feed bin and the mixer. Use a 9/16 inch (14.3 mm)
screen for surface and intermediate mixes and a 1.5 inch screen for base
mixes. Do not use concurrent project RAP in a stream process.
3. RAS Processing and Usage. Include RAS in a JMF
submittal according to the Standard RAP/RAS Limits Table 401.04-1 or Extended RAP/RAS Limits Table 401.04-2 unless specified differently in the
applicable mix specification.
Ensure RAS is
processed to have 100 percent passing the 1/2 inch sieve and at least 85
percent passing the No. 4 sieve. Ensure RAS has less than 1.0 percent
deleterious materials and 0.1 percent metals by weight. Do not blend RAS
from manufacturing waste and RAS from roofing tearoffs.
Ensure the approved QCP includes RAS usage methods before using RAS. Include in
the contractor QCP what contractor requirements apply
to the RAS processor.
Introduce and control
RAS in asphalt plants in the same manner as RAP is introduced and
controlled. RAS for base courses may be preblended
with RAP if using rate control equipment to ensure uniformity of blending and
if satisfactory blend and production is achieved. RAS may be preblended with a small amount of virgin aggregate meeting 703.05 to minimize stockpile
agglomeration. Include in the contractor QCP
blending equipment type and operation and uniformity testing requirements for preblended RAP and RAS or RAS and virgin aggregate.
Other methods must be approved by the Laboratory.
RAP and RAS QC and Management
Requirements.
Maintain as part of the QC records the signed certification forms as required
in Supplemental Specification 1116.
Always
note on the daily quality control report how much RAP and RAS is actually being
used. Apply a tolerance of ± 5.0 percent on the amount of RAP used if
needed for a quality control adjustment but do not exceed the limits of Table 401.04-1 or Table 401.04-2,
whichever applies. If this adjustment is not adequate for maintaining
control of the mix submit a new JMF for
approval. Do not apply this tolerance to RAS.
Include
in the QCP methods to be used to meet Method 1 and
Method 2 requirements above and the following requirements:
Provide
enough space for meeting all RAP and RAS handling requirements at a hot mix
facility. Provide a clean, graded base for stockpiles that does not
collect water. Test blended RAP and RAS stockpiles to assure uniform
gradation and asphalt binder content. Ensure uniform stockpile properties
match the JMF submitted RAP and RAS properties unless
the uniform stockpile will be processed into the asphalt plant using plant cold
feed in line processing.
If
the uniform stockpile will be processed into the asphalt plant using plant cold
feed in line processing determine the processed RAP properties for use in the
mix design. Record in the JMF submittal both
the uniform stockpile and in line processed RAP properties.
If
desired, when applying Method 1 Standard RAP requirements, use concurrent
Department project RAP in a stream process in place of stockpiling and testing
for uniformity but do so in the following manner. Concurrent project RAP
must be taken from one existing mix type on the concurrent project or two
existing mix types if both mix types are taken at the same time in one pass of
the milling machine. Submit a new JMF for each
existing mix type on the project (or each milling pass of two types) desired
for use as concurrent project RAP. Include in the QCP
methods of validating RAP properties when using concurrent project RAP. If
these requirements are not met blend and test for uniformity and apply the
stockpile requirements of this specification.
Maintain
in the plant lab and control room an up to date and dated site map of all
tested and untested RAP and RAS stockpiles. Give each stockpile a unique
identification and identify if RAS piles are from un-used manufactured shingle
waste or used roofing tear-off shingles. Provide in the plant lab RAP and
RAS properties for each uniform, blended stockpile cross referenced with its
identification. In addition, provide the date the stockpile processing was completed
and the stockpile estimated size in tons. The DET
may require RAP and RAS pile staking for failure to maintain the above.
Do not add to a stockpile once it is tested for uniformity. Provide
signage at all uniform stockpiles to inform haulers that uniform piles are not
to be added to.
Stockpiles
and processing methods are subject to inspection and approval by the DET at any time. Rejection of stockpiles can occur
for the presence of foreign or deleterious materials, lack of uniformity,
incomplete mixing in the asphalt mixture, adding to piles, or moving RAP or RAS
in a way not traceable through the QCP records and
methods. The Laboratory will resolve disputes over acceptability of RAP
or RAS.
401.05 Mixing Plants. The Department
will approve mixing plants before preparation of the mixtures. Schedule a
date with the Department for approval inspection to be at least 1 week before
mix production. Do not produce mixtures for projects from un-approved
plants. General requirements for asphalt concrete mixing plants are
specified in Item 402.Set the asphalt binder controls for
the computerized plant at the virgin asphalt binder content of the JMF at all times unless change is authorized by the
Laboratory.
Asphalt
mixtures may be produced using the warm mix asphalt method according to 402.04 except as restricted by specification.
401.06 Weather Limitations. Place
asphalt concrete only if the surface is dry and if weather conditions are such
that proper handling, finishing, and compaction can be accomplished.
Never place asphalt concrete if the surface temperature is below the minimum
established in Table 401.06-1.
Course Thickness |
Minimum Surface Temperature |
|
3.0 inches (75 mm) and over |
36 °F [1] |
(2 °C [1]) |
1.5 to 2.9 inches (38 to 74 mm) |
40 °F |
(5 °C) |
1.0 to 1.4 inches (25 to 37 mm) |
50 °F |
(10 °C) |
Less than 1.0 inch (25 mm) |
60 °F |
(16 °C) |
Variable Intermediate, |
40 °F |
(5 °C) |
[1] Instead
of 36 °F (2 °C), use a minimum air temperature of 40 °F (5 °C) if paving on
an aggregate base or subgrade. |
In
addition to the above surface temperature requirements, do not place surface
courses if the air temperature is less than 40 °F (5 °C).
For
Type 1H asphalt concrete or any surface course with a polymer modified asphalt
binder, ensure that the surface of the existing pavement is at least 50 °F
(10 °C) and the air temperature is at least 50 °F (10 °C).
Do
not schedule the placement of any Type 1H asphalt concrete or any surface
course with a polymer modified asphalt binder after November 1, regardless of
pavement or air temperature.
401.07 Notification. Notify the Engineer at
least 24 hours before starting paving on a project. After starting
paving, if paving operations are stopped for 1 week or more, notify the
Engineer at least 24 hours before resuming paving on a project.
401.08 Asphalt Binder. Heat the asphalt binder
and deliver it to the mixer within the temperature range specified in Table 702.00-1. Do not use asphalt binder
while it is foaming in a storage tank. Take samples using correct new
containers from the binder line between the last piping ‘tee’ and inlet into
the plant unless a different storage method requires a different sampling
location.
401.09 Aggregate Preparation. Feed
aggregates in their proper proportions and at a rate to permit correct and
uniform control of heating and drying. Remove all aggregates in the plant
that will produce a mix outside the temperature limits or that contain
excessive moisture or expanding gases causing foaming in the mixture, and
return them to the proper stockpiles.
401.10 Mixing. Maintain the temperature of the
mix at the plant within the range set by the Laboratory for the JMF or according to the specification. The Engineer
will determine the required temperature of the mixture on arrival at the
project site based on the temperature range set for the mix design and heat
losses in transit.
For
batch plants, after all of the aggregate is in the mixer, add the asphalt
binder in an evenly spread sheet over the full length of the mixer. The
mixing time is defined as the interval between the start of application of the
asphalt binder and the opening of the mixer gate. Discharge all asphalt
binder required for one batch in not more than 30 seconds. After the
asphalt binder is added, the Laboratory will establish a minimum mixing time,
which will not be less than 30 seconds.
401.11 Hauling. Use trucks for hauling asphalt
concrete that have tight, clean, smooth metal beds from which the entire
quantity of mixture is discharged smoothly into the spreading equipment.
Before loading,
apply a thin coating of an approved release agent to the inside surfaces of the
truck bed to prevent adhesion of mixture to the bed surfaces. The
Laboratory maintains a list of approved release agents. Do not use fuel
oil for this purpose. Drain truck beds before loading.
Provide a place
off the project for cleaning trucks when hauling polymer modified asphalt
binder mixes or when excessive sticking of material in truck beds occurs.
If the Contractor does not resolve excessive sticking of material in truck beds
in a reasonable time and the sticking is in areas of the truck that would
indicate excessive cooling of the mix (front corners, bottom, etc.) due to a
long haul, the Engineer will require an insulated bed. The Contractor may
only make changes in policy regarding release agents for beds or other
procedure changes for better mix handling at the discretion of the Laboratory.
Equip
each truck with a securely fastened, waterproof cover of suitable material to
adequately protect the mixture from wind and weather. At the request of
the Engineer, remove covers before dumping into the paver.
If
transporting hot asphalt concrete at prevailing air temperatures below 50 °F
(10 °C) or if the length of haul exceeds 20 miles (32 km), insulate all
truck beds to maintain workable mix temperature, and ensure that all covers are
fastened to exclude the wind. Do not exceed a distance of 50 miles (80
km) from the asphalt concrete plant to the paving site except by specific
permission of the Department.
401.12 Spreading Equipment. Use
self-contained spreading equipment of sufficient size, power, and stability to
receive, distribute, and strike-off the asphalt concrete at rates and widths
meeting the typical sections and other details shown on the plans. Use
spreading equipment that has automatic control systems that maintain the screed
in a constant position relative to profile and cross-slope references.
Ensure control of the screed position is reasonably independent of
irregularities in the underlying surface and of the spreader operation.
Equip asphalt spreading equipment to prevent the segregation of coarse
aggregate from the remainder of the asphalt concrete when the material moves
from the hopper to the screed. Use means and methods approved by
the asphalt spreader manufacturer consisting of but not limited to any
combination of chain curtains, deflector plates, or other such devices.
For
the following asphalt spreaders perform the listed modifications:
A.
Equip Blaw-Knox asphalt spreaders with the Blaw-Knox Materials Management Kit (MMK)
or an alternate equivalent kit. If an alternate kit is used provide documentation
showing the Blaw Knox means and methods and that the
alternate methods used are equivalent.
B.
Only use Cedar Rapids asphalt spreaders manufactured after 1988.
C.
Equip Caterpillar asphalt spreaders with deflector plates as identified in the
Caterpillar December 2000 Service Magazine entitled “New Asphalt Deflector Kit
{6630, 6631 or 6640}”.
Provide
a letter to the Engineer identifying modified asphalt spreaders to be used and
provide a certification statement and signature that the above modifications
were implemented on the listed asphalt spreaders.
The
Engineer will base final approval of spreading equipment on the demonstrated
capability of the equipment to place the mixture to the required cross-section,
profile and alignment in an acceptable, finished condition ready for
compaction.
Where
the use of standard full-scale spreading equipment is impractical due to the
size or irregularity of the area to be paved, use specialized equipment or hand
methods approved by the Engineer to spread the asphalt concrete.
401.13 Rollers. Use only steel wheel and
pneumatic tire types of rollers meeting the minimum requirements of the
following tables. Conform to manufacturer’s specifications for all
ballasting.
table
401.13-1 ROLLER CAPACITY
Roller Type |
Maximum Capacity |
Tandem |
700 (600) |
Three-Wheel |
700 (600) |
Trench |
15 per inch width (13 per 25 mm width) |
Pneumatic Tire, Type 1 |
1000 (850) |
Pneumatic Tire, Type 2 |
700 (600) |
Vibratory, Vibrating Roll |
15 per inch width (13 per 25 mm width) |
Vibratory, Static Roll (not vibrating) |
3 per inch width (3 per 25 mm width) |
table
401.13-2 STEEL WHEEL ROLLERS
Roller Type |
Three- |
Tandem |
Vibratory |
Trench |
Total weight, tons |
10 (9) |
8 to 12 (7 to 11) |
8 to 12 (7 to 11) |
|
Compression rolls, pounds per inch width (kN/m), minimum |
300 (53) |
200 (35) |
120 (21) |
300 (53) |
table
401.13-3 PNEUMATIC TIRE ROLLERS
Type I |
|
Tire size, minimum |
9.00 x 20 in (229 x508 mm) |
Wheel load, minimum |
5000 lb. (2250 kg) |
Average tire contact pressure, minimum |
85 psi (590 kPa) |
Type II |
|
Tire size, minimum |
7.50 x 15 in (191 x 381 mm) |
Wheel load, minimum |
2000 lb. (900 kg) |
Average tire contact pressure, minimum |
55 psi (380 kPa) |
For
pneumatic tire rollers, use self-propelled, reversible units with vertical
oscillation on all wheels on at least one axle. Determine the tire
inflation pressure necessary to meet the specified minimum contact area and
contact pressure requirements. Furnish the tire manufacturer’s charts or
tabulations to the Engineer for verification of the required inflation
pressure. Check tire inflation pressure as the Engineer directs and
maintain it within 5 pounds per square inch (35 kPa)
of the required pressure.
Provide
rolls and wheels with the necessary accessories to prevent adhesion of the mixture,
and keep them properly moistened with water, water containing a detergent, or
water containing an approved additive. Do not use excess liquid.
401.14 Conditioning Existing Surface. Clean the
surface on which the asphalt concrete is to be placed, and keep it free of
accumulations of materials that would, in the judgment of the Engineer,
contaminate the mixture, prevent bonding, or interfere with spreading
operations. Where approved subgrade or pavement courses previously
constructed under the Contract become loosened, rutted, or otherwise defective,
correct the deficiency according to the contract item or items involved before
the spreading of a subsequent pavement course.
If a quantity of
asphalt concrete is specified for use in spot leveling or patching an existing
pavement surface, spread and compact the material needed to effect the
corrections as directed by the Engineer.
Paint contact
surfaces of curbing, gutters, manholes, and other structures with a thin,
uniform coating of asphalt material before placing the asphalt concrete against
them.
If placing
asphalt concrete against the vertical face of an existing pavement structure,
clean the vertical face of foreign material and apply asphalt material that
results in a coating of approximately 0.25 gallon per square yard (1 L/m²).
Before placing a
surface course onto an intermediate course, apply a tack coat to the
intermediate course according to 407.06.
In
areas where the surface is required to be feathered to meet an adjoining
surface, coat the existing surface uniformly with a thin coat of asphalt
binder.
401.15 Spreading, Finishing and Night Work
Spreading
and Finishing.
Spread the mixture at a rate calculated using the specified thickness and the
compacted width of the pavement course being placed, and the weight-to-volume
conversion factors established in 401.21.
Maintain the actual rate of spreading the mixture equal to the required
calculated rate within the tolerance specified in 401.19. For pavement
courses specified for leveling an existing pavement surface, the actual rate of
spreading the mixture may vary from the required calculated rate as approved by
the Engineer to accomplish the intended purpose.
For intermediate
courses, make the maximum compacted depth of any one layer 3 inches (75 mm).
Spread and
finish the mixture using approved equipment or methods such that compaction can
follow immediately. Preheat screeds and extensions before placing any
asphalt concrete. Use side plates sufficient to contain the mixture
laterally during spreading. Use only screed extensions, rigid or
extendable, having the same features as the main screed including, but not
limited to, vibration, heating, pre-strikeoffs, and
tamping bars. When using front-mounted hydraulically extendable screeds
at a fixed paving width use full width auger extensions and full tunnel
extensions. When using fixed screed extensions use full width auger
extensions and full tunnel extensions. Do not allow a buildup of excess
material in front of any extended screed. Where excessive buildup of
material is not controlled in front of the extended screed, the Engineer will
require paver changes to correct the problem.
Ensure
the paver operation, screed, screed extension, and, or, mix design provide a
mat, prior to compaction, that is free of texture inconsistencies, shadowing,
streaking, tearing, pulling, or other deficiencies. Take immediate action
to correct the paver operation, screed, screed extensions, or, mix
design. The Engineer may stop placement until corrections are completed.
Use strike-off
plates/strike-off extensions only on irregular areas such as mailbox turnouts,
driveway turnouts, and other irregular non-travelled roadway areas. The Engineer
may approve the use of strike-off plates/extensions on variable width shoulders
if the use of a standard extendable screed extension with the same features as
the main screed is not practicable. Perform supplemental hand forming and
tamping where irregularities develop and where placing the mixture by hand
methods.
Take prompt
corrective action if placed mixture is not free of any defect (ex. segregation,
tenderness, lack of mixture and texture uniformity, raveling, flushing,
rutting, holes, debris etc.) within the Contractor’s control and as determined
by the Engineer. Remove and replace, or otherwise correct, any portion of
the pavement course found to be defective in surface texture or composition
before or after compaction in a manner satisfactory to the Engineer.
Coordinate the spreading operation with the rate of production and delivery of
the mixture to attain uniform, continuous progress. Avoid erratic
spreader operation due to irregular contact with the hauling vehicle, surging
in the feed and distribution of the mixture, or other cause. Maintain
sufficient control of the spreading equipment with regard to line and grade
references so that the pavement course, when compacted as specified, is in
reasonable conformance with the Contract Documents.
Do not displace
or damage bridge deck waterproofing membranes during spreading operations on
the membranes.
Do not allow
traffic on the compacted mixture until it has cooled sufficiently to prevent
glazing as determined by the Engineer.
After completion
of the surface course, seal gutters with asphalt binder as directed by the
Engineer. Apply the material at a uniform width of approximately 4 inches
(100 mm) and at a rate just sufficient to fill surface voids.
Night Work. Do not
start night work or carry on day work into night work without operating an
adequate and approved lighting system. Night work is defined as work
performed from 30 minutes before sunset to 30 minutes after sunrise.
Operation
of adequate lighting system consists of furnishing, installing, operating,
maintaining, moving, and removing night time lighting to illuminate
construction work areas for night work. Obtain the Engineer’s approval of
the lighting at the beginning of the project and before starting the paving operation
by measuring the luminance.
Provide
an illuminated zone around all operating machinery. Provide an
illuminated zone of at least 5 Foot-candles (55 lux) of lighting luminance in
the immediate vicinity of pavers, rollers, grinding equipment, material
transfer vehicles, etc., and at least 1 Foot-candle (10 lux) at 25 feet (7.6 m)
from this equipment. Provide an illuminated zone of at least 5
Foot-candles (55 lux) of lighting luminance in the immediate vicinity of coring
equipment and at least 1 Foot-candle (10 lux) at 10 feet (3m). Position
the light sources so they don’t interfere with or impede traffic in any
direction and do not cause glare for motorists or point onto adjacent
properties. Provide a photometer capable of measuring the level of luminance
on each night project. Take luminance measurements at a height of 20 inches
(500 millimeters) above the roadway.
Obtain
the luminance level any time requested by the Engineer. Test the illumination
levels on the site each time a change in lighting configuration is made.
Replace non-functioning lamps immediately. Check the luminaires aiming
daily. Clean the luminaires regularly. Correct any deficient
lighting within one hour or the Engineer will terminate construction activities.
When
the total project includes more than one continuous lane mile (including
bridges) of surface course paving in combination with night paving, provide a
Material Transfer Vehicle (MTV) with paver hopper insert; a Material Transfer
Device (MTD) with paver hopper insert; or a remixing
paver specifically manufactured to eliminate segregation.
Provide
equipment that:
A.
Includes a mixer/agitator mechanism that consists of either segmented,
anti-segregation, re-mixing augers or two full-length longitudinal paddle
mixers specifically designed for the specific purpose of re-mixing. The
longitudinal paddle mixers shall be located in the paver hopper insert.
B.
Eliminates segregation, and provides a uniform temperature throughout the
mixture;
C.
Limits temperature differentials to less than 25 °F (14 °C);
Use
the equipment on all mainline lanes of the traveled way including express
lanes, collector-distributor lanes, continuous center turn lanes, acceleration/
deceleration lanes, and ramp lanes.
Use
paver hopper inserts with a minimum capacity of 14 tons. Remixing may be
done by the MTV or MTD, in the paver hopper insert,
or by the remixing paver.
Demonstrate
to the Engineer that the selected equipment eliminates physical segregation and
limits the temperature differential of the mat surface measured transversely to
25 °F (14 °C). Provide a method before the start of paving that ensures
non-segregation and thermal differential requirements are met, continuously
during placement operations.
Remove
equipment that does not consistently eliminate physical segregation and, or,
does not meet the temperature differential requirement.
401.16 Compaction. Immediately after spreading the
asphalt concrete and adjusting any surface irregularities, compact the mixture
uniformly using rollers conforming to 401.13. Do not use a spreading rate
that exceeds the total of the specified capacities of the rollers in use.
However, if compacting a mixture spread as an intermediate or pre-leveling
course less than 1-inch (25 mm) thick do not use a spreading rate that exceeds
twice the total capacity of the rollers in use.
Coordinate
the spreading of the mixture with the required roller coverage, considering the
rate of cooling of the mixture as affected by lift thickness and environmental
conditions. Complete the required roller coverage during the period of
time in which the temperature of the mixture is sufficient for the roller
coverage to be effective in compacting the mixture.
Compact
base mixtures using a combination of both steel and Type I pneumatic tire
rollers; however, in small areas, compact these mixtures as approved by the
Engineer using any of the rollers specified in 401.13.
Compact
intermediate and surface mixtures using a three-wheel roller in the breakdown
position (roller immediately behind the paver) of the roller train; however, in
small areas, compact these mixtures as approved by the Engineer using any of
the roller types specified in 401.13.
Compact
variable depth courses using a combination of both steel and pneumatic tire
rollers; however, in small areas, compact these mixtures as the Engineer
approves using any of the roller types specified in 401.13.
For
surface courses using a polymer modified asphalt binder give a copy of the JMF approval letter containing the design compaction
temperature to the Engineer before any mix is placed. Unless otherwise
specified ensure that the mix temperature immediately before rolling is not
less than 290 °F (145 °C) if placing hot mix asphalt, and not less than 250 °F
(121 °C) if placing warm mix asphalt according to 402.04.
Do not compact polymer asphalt concrete surface
courses with pneumatic tire rollers.
When
using pneumatic tire rollers, ensure for any mix, that surface deviations and
deformations caused by the tires are removed with steel wheel rollers. Do
not use pneumatic tire rollers if any resultant surface deformations cannot be
removed.
Do
not use vibratory rollers on courses with a thickness under 1 1/2 inches (38
mm).
If
using vibratory rollers, supplement them with three-wheel or pneumatic tire
rollers.
Unless
otherwise directed, begin rolling at the sides and proceed longitudinally
parallel to the centerline at a slow, uniform speed. After each coverage
or complete round trip, move the roller towards the crown of the road to begin
its next pass, overlapping the previous pass by at least one-half the width of
the previous pass. On superelevated curves,
begin rolling at the low side and progress toward the high side. Where a
longitudinal joint is being made, roll the joint then follow the applicable
rolling procedure.
Continue
rolling until full coverage of the course is complete and all roller marks are
eliminated. Take care to prevent displacement of the edge line and
grade. Where displacement occurs, correct the area immediately in a
manner satisfactory to the Engineer.
Along
curbs, headers, walls, and in other areas not accessible to rollers, thoroughly
compact the mixture with hot, hand tampers or with mechanical tampers. On
depressed areas, the Contractor may use trench rollers or rollers fitted with
compression strips.
Replace
mixture that becomes loose, broken, contaminated, or otherwise defective with
fresh, hot mixture. Compact it to match with the surrounding area.
401.17 Joints. Place the asphalt concrete
mixture as continuous as possible. Set up joints at the proper height
above the adjacent construction to receive maximum compaction. Where the
edge of the new surface has been significantly rounded by the action of
traffic, trim it to a vertical face before placing the adjacent pavement.
On projects where traffic is allowed to cross the edge of the new pavement
lane, complete the longitudinal joint of the adjacent lane or berm within 24
hours.
Form
hot longitudinal joints using pavers operating in contiguous lanes, one just
ahead of the other. Maintain the distance between pavers in adjacent
lanes such that it does not exceed the distance that a normal size load of
mixture will cover. Alternate loads of mixture between
the pavers. Do not allow rollers performing the
initial rolling operation in one lane closer than 12 inches (0.3 m) to the
longitudinal joint until the adjacent lane is placed.
Instead
of hot joint construction using multiple pavers, the Contractor may use full
width construction with a single unit paver.
Compact
all cold longitudinal joints on intermediate and surface courses using a
three-wheel roller.
For
surface courses, form or cut all transverse construction joints to a vertical.
Seal all cold
longitudinal construction joints by coating the entire face of the cold joint
with a certified 702.01 PG binder or 702.13 SBR Asphalt
Emulsion to provide 100 percent coverage of the joint. Overlap the joint
edges by at least 1/2 inch (13 mm). Seal all cold transverse construction
joints with a certified 702.01 PG binder
or 702.13 SBR
Asphalt Emulsion to provide 100 percent coverage of the joint or with a
certified 702.04 asphalt material applied
at a rate of 0.25 gallon per square yard (1 L/m²).
401.18 Asphalt Binder Compatibility. If excess fat
spots, regular random areas of flushing, or excess drain down occur on a
project that are not attributable to over rolling, plant operation, or mix
quality compared to the JMF, the Department will
consider the asphalt binder incompatible. The Department will reject any
on-hand asphalt binder because of incompatibility. The Department may use
its discretion in determining if problem areas can be corrected, but if an
unsafe condition exists, remove and replace the area in question.
Demonstrate to the Laboratory through reporting actual testing analysis the
compatibility of another asphalt binder and that proper equipment is in place
in order to be allowed to resume.
401.19 Spreading and Surface Tolerances. If a
uniform course is specified, make checks and adjustments to maintain the rate
of spreading within a tolerance of ±5 percent of the required calculated weight
per unit of area.
If
a variable depth course is specified, place the mixture as shown on the plans.
If
a longitudinal profile is specified by elevations on the plans, do not allow
the completed pavement surface to deviate more than 1/2 inch (13 mm) at any
point from parallel with the specified profile. Before placing the
surface course, check the profile of the preceding course at
50-foot (15 m) intervals along the outside edge of each traffic lane and along
any additional line described in superelevation
tables, and submit a tabulation of all results that includes
documentation of all deviations from the above tolerance to the Engineer.
Perform corrective work necessary for compliance with the profile tolerance
before placing the surface course. The requirements of this paragraph do
not apply to small incidental areas of pavement less than 500 feet (150 m) in
length.
Do
not vary the transverse slope of the surface of the completed course from the
specified slope by more than 3/8 inch in 10 feet (10 mm in 3 m).
Do
not vary the surface of each completed intermediate or surface course from the
testing edge of a 10-foot (3 m) rolling straightedge by more than 1/4 inch (6
mm). Furnish straightedges, straightedges equipped with levels, or other
devices such as approved profilers conforming to S1058
and using ProVAL
software. Equipment will be satisfactory to the Engineer.
Check
the surface course for variations in slope or surface at locations where bumps
are suspected when directed by the Engineer.
Correct
variations in excess of slope or surface tolerance by removing mixture to neat
lines and replacing, or by surface grinding in a manner satisfactory to the
Engineer.
401.20 Asphalt Binder Price Adjustment. A
contract item is eligible for a price adjustment when the contract’s proposal
specifically includes an Asphalt Binder Price Adjustment note and the contract
item meets the quantity limitations of the proposal note.
401.21 Method of Measurement. The
Contractor is responsible for recording the net weight of each truckload of
mixture to the nearest 100 pounds (50 kg) in triplicate on plant ticket forms
approved by the Department. If the pay quantities are established by
platform scales, provide a tare weight for each truck at the beginning of each
day’s operation and a minimum of every 4 hours of operation each day. The
Engineer may require additional tare weight measurements at any time. The
Engineer will have the right to monitor all weighing operations and may require
reweighing trucks at any time or location. Correct any discrepancies
immediately. Continued non-compliance will result in the Department
taking necessary and appropriate action, such as, but not limited to, assigning
a Department ticket writer to the plant. Send one copy of the plant ticket
with each load delivered to the paver and present it to the Engineer.
The
Engineer will convert the total of the weights recorded on the plant tickets
representing mixture finished according to contract requirements to cubic yards
(cubic meters) using a conversion factor established by the Laboratory.
The Laboratory will establish this conversion factor from the approved JMF. However, if a mix design is not available, the
Laboratory will use the conversion factors in Table 401.21.
If a uniform course is specified, the Department will not pay for a number of
cubic yards (cubic meters) that exceeds the quantity calculated from plan lines
and dimensions.
Aggregate |
lb/yd³ |
(kg/m³) |
Gravel and stone |
4000 |
(2370) |
Slag less than 90 lb/yd³ (less
than 1450 kg/m³) [1] |
3600 |
(2135) |
Slag 90 to 100 lb/yd³ (1450 to
1600 kg/m³) [1] |
4000 |
(2370) |
Slag more than 100 lb/yd³ (more
than 1600 kg/m³) [1] |
4300 |
(2550) |
[1] Based on average dry rodded weight at the Laboratory. |
401.22 Basis of Payment. The
Department will pay for all work performed and measured as specified above
according to the appropriate contract items for each type.
The
cost of sealing the joints is included in the unit price bid for the asphalt
concrete.
The
Department will assess all costs against the Contractor that it incurs as a
result of taking necessary and appropriate action due to the Contractor’s
continued non-compliance.
If an unsafe condition
exists, the Department will not pay for removing and replacing incompatible
asphalt binder areas.