Suggested Polymer
Modified, Fiber Reinforced Overband Crack Sealant Specifications
XXX.010 General
XXX.020 Materials
XXX.021 LIquid SBR Polymer
XXX.022 Polyester Fibers
XXX.023 Asphalt Cement
XXX.030 Equipment
XXX.031 Compressed Air
System
XXX.032 Melter Applicator
XXX.033 Application Wand
XXX.034 Heat Lance
XXX.040 Manufacture
XXX.050 Construction
XXX.051 Crack Preparation
XXX.052 Application
XXX.053 Weather Limitations
XXX.054 Protecting the
Work
XXX.060 Required Project
Documentation
XXX.070 Acceptance of
Work
XXX.080 Measurement and
Payment.
XXX.01 General. Clean
cracks in hot mix asphalt (HMA) pavements and place the specified materials
into and over the crack. Place temporary pavement markings where overband
crack sealant obliterates the existing pavement markings.
For this specification, the
Owner's Department of Engineering shall be known as the Department.
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XXX.020 Materials. The
overband crack sealant shall be composed of a mixture of liquid SBR polymer,
polyester fibers and asphalt cement blended by weight in the following
quantities:
Liquid
SBR Polymer
Polyester Fibers
Asphalt Cement |
5+0.5%
5+0.5%
90%+1.0% |
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XXX.021 Liquid SBR Polymer.
The liquid
SBR polymer shall be a virgin unvulcanized styrene butadiene synthetic
rubber polymer meeting the following requirements:
| Typical
Properties | |
| Ash, % of Total Polymer Solids, ASTM D 297 | 3.0 Max |
| Volatile Content, 5 hrs@105°C,% | 5.0 Max |
| Coagulum on 80 mesh screen,% | 0.2 Max |
| Mooney Viscosity of Polymer, M/L 4@100°C | 95 Min |
| Brookfield Viscosity @ 25°C,cps | 80,000 Max |
| Flash Point, °C, Pensky-Martin method, ASTM D 93 | 150 Min |
The manufacturer of the liquid
SBR polymer shall certify compliance with this specification.
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XXX.022 Polyester Fibers.
The polyester
fibers shall meet the following requirements:
| Length,mm | 6+0.05M |
| Crimps, ASTM D 3937 | None |
| Tensile strength, Mpa, ASTMD 2256 | 480 min |
| Denier, ASTM D 1577* | 6.0 |
| Specific gravity | 1.32 - 1.40 |
| Melting temperature, °C | 245 min |
| Ignition temperature °C | 540 min |
*These data must be obtained
prior to cutting the fibers.
The manufacturer of the polyester
fibers shall certify compliance with this specification.
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XXX.023 Asphalt Cement.
The asphalt
cement shall be a standard paving grade asphalt AC-10, PG 58-28 or PG 64-22
and shall have a penetration value of 85-100.
The manufacturer of the asphalt
cement shall certify compliance with this specification.
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XXX.030 Equipment. The
Contractor shall use the equipment specified herein to mix and install
the overband crack sealant.
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XXX.031 Compressed Air
System. Furnish
and use a compressed air system that produces a continuous, high volume,
high pressure stream of clean, dry air to prepare cracks. Equip the air
compressor with a moisture separator to remove all oil and water from the
air supply. Provide a compressor that can produce a minimum of 100 psi
and continuous 150 cfm air flow.
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XXX.032 Melter Applicator.
Provide a
melter applicator consisting of a boiler kettle equipped with a pressure
pump, hose and applicator wand. Equip the hose with a shutoff control.
Place a mechanical full-sweep agitator in the kettle to provide continuous
blending. Equip the unit with thermometers to monitor the material temperature
and the heating oil temperature. Provide thermostatic controls that allow
the operator to regulate material temperature up to 360 F.
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XXX.033 Application Wand.
Apply the
material by either a wand followed by a "V" or "U" shaped squeegee or a
round applicator head having a concave underside.
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XXX.034 Heat Lance. Use
of a heat lance to assure that no residual moisture is present in the crack
or on the pavement surface is allowed.
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XXX.04 Manufacture. The
overband crack sealant shall be blended in the specified melter applicator.
The temperature of the material shall be maintained between 320-360 °F.
Weigh tickets for the asphalt cement shall be used in determining the specified
weight of the liquid SBR polymer and the polyester fibers to be blended
into the asphalt cement. Fill the tar kettle with the asphalt cement. It
is essential that the asphalt cement is in the kettle prior to the addition
of the liquid SBR polymer in order to produce a uniform blend and prevent
clogging the lines with polymer not uniformly blended with the asphalt
cement. Mix the asphalt cement in the kettle with the agitator while slowly
adding the liquid SBR polymer. Continue mixing for approximately 10 minutes
or until a uniform blend has been obtained. The polyester fibers shall
then be added and mixed until a uniform blend has been obtained.
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XXX.050 Construction.
A pre-construction
meeting shall be held with the Department prior to beginning the work to
discuss the following:
1. The Contractor's detailed
work schedule.
2. The traffic control plan.
3. Required project documentation.
4. Inspection of the condition
and adequacy of equipment.
The Contractor shall designate
an Authorized Contractor's Representative at the pre-construction meeting.
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XXX.051 Crack Preparation.
Clean cracks
using compressed air and other tools necessary to remove all loose dirt,
vegetation and foreign material. Clean cracks no more than 10 minutes ahead
of the sealing operation. Use of a heat lance is allowed to assure that
no residual moisture is present in the crack or on the pavement surface
where the overband crack sealant is to be applied. Do not attempt to seal
soaked pavement cracks by drying the pavement surface with a heat lance.
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XXX.052 Application. Apply
the overband crack sealant using the specified application wand to dry
and thoroughly clean cracks. The overband crack sealant shall be 4 inches
wide and 1/8 to 3/16 inch thick. Upon prior written approval of the Department,
application width may be increased to a maximum of 6 inches to provide
complete and uniform coverage over multi-crack areas. When no other surface
treatment will be applied to the pavement, fill all visible cracks in the
pavement. When preparing the pavement for a micro-surface overlay, fill
all visible in the pavement. When preparing the pavement for a single or
double chip seal, limit sealing to cracks more than 1/8 inch wide or 3
feet long. Seal cracks with varying widths, portions of which are 1/8 inch
or greater, along their entire length.
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XXX.053 Weather Limitations.
Overband crack
sealant shall be placed when the air temperature is between 45 F and 85
F. No overband crack sealant shall be placed unless the pavement is dry
and the cracks are free of moisture.
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XXX.054 Protecting the
Work. The
Contractor must allow the overband crack sealant to cool sufficiently before
opening to traffic. Blotting materials such as sand, aggregate, sawdust
or paper is prohibited. Any damage by traffic to the treated pavement areas
shall be repaired by the Contractor at no expense to the Department. If
the existing pavement marking are obliterated as a result of the crack
sealing work, temporary pavement markings shall be placed before the roadway
is opened to traffic at the Contractor's expense.
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XXX.06 Required Project
Documentation. On
a daily basis the Contractor shall provide a report to the Department with
the following information:
1. Control section, job
number and route number
2. Date, air temperature
(°F), AM and PM weather
3. Beginning and ending
locations for the day, including lane(s) and direction
4. Quantity of materials
used for the day, including lot number
5. Traffic control typically
used, number of traffic control modes and checks on the traffic control
conducted
6. Unique or different situations
on the project
Documentation provided by
the Contractor shall contain the signature of the Contractor or the Contractor's
Authorized Representative.
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XXX.07 Acceptance of Work.
When the work
is complete on the project, or on a route or job included in the project,
schedule an inspection of the work with the Department. The Department
will note all deficiencies including areas exhibiting adhesion failure,
cohesion failure, missed cracks or other factors that show the work is
not acceptable. Areas requiring corrective work as identified by the Department
will not be deemed acceptable. Notify the Department upon completion of
required corrective work or upon completion of work on the route, job or
project if corrective work is not required.
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XXX.08 Measurement and
Payment.
Contract
Item (Pay Item)
Overband Crack Seal, Roadbed
Overband Crack Seal, Ramp
Overband Crack Seal, Parking
Area |
Pay
Unit
Roadbed Mile
Roadbed Mile
Parking Area |
Overband crack seal includes
preparing and sealing cracks; providing the required documentation and
all corrective action and temporary traffic markings required. Overband
Crack Seal, Roadbed will be measured along the roadway centerline and will
include the traffic lanes, the paved shoulders and all auxiliary lanes.
For a divided highway the roadbed will be measured separately in each direction.
Overband Crack Seal, Ramp will be measured along the ramp centerline and
will include the traffic lanes, the paved shoulders and all auxiliary lanes.
Overband Crack Seal, Parking Area will be measured and payment made as
a single unit for each parking area identified by location and area.
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IMPORTANT NOTICE TO THE
ENGINEER. The foregoing is for engineers only for the purpose of assisting
them in preparing job specifications. Suggested specifications are for
use under what may be termed “average conditions”. No single standard specifications,
however, will cover satisfactorily all variations in local conditions relevant
to individual jobs. Before adopting suggested specifications, the owner's
engineer should give particular consideration to any special problems and
make such changes as are necessary. Nothing contained herein shall be construed
as recommendations or inducements to practice any invention covered by
patent without permission of the patent owner.
