Addendum - 2.pdf

ADDENDUM - 2

Request for Proposal (RFP) for Asphalt Pavement repairs

TECHNICAL SPECIFICATIONS MILLING & OVERLAY

(Project includes Golfview Drive Asphalt Pavement Repairs)

SPECIFICATIONS FOR

COLD MILLING HMA SURFACE

Description

This work shall be in accordance with Division 5, Section 501 of the 2012 MDOT Standard Specifications, except as herein specified & include all labor, equipment and materials to complete full removal, loading, hauling and disposal of the milled material as called for in the plans.

All mater ia l mus t be d i sposed o f a t an o f f -site l oca t ion des igna t ed by t he C o n t r ac to r

HOT MIX ASPHALT (HMA)

This work shall be in accordance with Division 2, Section 204 and Division 5, Sections 501, 502, 503, 504, and 505 of the 2012 MDOT Standard Specifications For Construction, MDOT’s Special Provision for Marshall Hot Mix Asphalt Mixture (SP501(F)), Table 1 of MDOT’s Special Provision for Acceptance of HMA Mixture on Local Agency Projects (12SP-501J-03), MDOT’s Local Agency Programs Hot Mix Asphalt (HMA) Selection Guidelines and except as herein specified.

Any possible inconsistencies that may exist between the requirements included herein, will be resolved by the ENGINEER at the time such inconsistency is identified.

The CONTRACTOR shall install the Hot Mix Asphalt (HMA) to the dimensions and thickness shown on the plans.

Mixtures

1. All HMA on this project shall be MDOT Mix Types: 5E1

2. The Job Mix Formula (JMF) and Mix Design shall be submitted to the ENGINEER for approval a minimum of 10 business days prior to paving. Do not begin production and placement of the HMA until receipt of the ENGINEER’s approval of the JMF.

3. The PG binder grade, application rate and Aggregate Wear Index (AWI) will be as defined in the MDOT Local Agency Program’s Hot Mix Asphalt (HMA) Selection Guidelines.

Alternative mixes will not be allowed.

4. The HMA will be designed using Marshall Mixture Design Methods in accordance with the MDOT Standard Specifications For Construction and as modified in the MDOT Special Provision For Marshall Hot Mix Asphalt Mixture (12SP501(F)). Maintain the binder content, aggregate gradation, and the crushed particle content of the HMA mixture(s) within the Range 1 uniformity tolerance limits in Table 1 of MDOT Special Provision (12SP-501J-03).

For all mixtures, field regress air void content to 3.5% with liquid asphalt cement unless specified otherwise on the HMA application estimate.

5. Aggregates produced from steel furnace slag, reverberatory furnace slag or crushed concrete shall not be permitted in any HMA mixture. Topsoil, clay, or loam cannot be added to aggregates which are to be used in plant mixed HMA mixtures.

6. The aggregate portion retained on the No. 4 sieve shall not contain by weight more than 6% particles which are soft or non durable.

7. Recycled Asphalt Pavement (RAP) may be substituted for a portion of new materials required to produce the HMA mixture(s) as follows:

a. For the HMA Top Course, a maximum of 17% RAP binder by weight of the total binder in the mixture will be allowed.

b. For HMA Base Course and Leveling Course mixtures, a maximum of 27% RAP binder by weight of the total binder in the mixture will be allowed. For HMA Base Course and Leveling Course mixtures containing 18% to 27% RAP, the required asphalt binder grade Must be at least one grade lower for the lower temperature than the design binder grade required for the specified mixture type. For instance, for a design binder grade of PG-58-22, the required grade for the binder in the HMA mixture containing 18% to 27% RAP would be a PG 58-28.

8. No Recycled Asphalt Shingles (RAS) will be allowed in the HMA mixture(s).

9. The CONTRACTOR will specify the temperature of the HMA mixture(s) at placement when submitting the JMF to the ENGINEER for review and approval.

Installation

1. The HMA shall be placed by the self-propelled mechanical paver or spreader to a depth that, when compacted, the mixture will have the thickness, width and slope specified or as directed by the ENGINEER.

2. Paths placed in thickness of 250 pounds per square yard, or less, may be placed in one course.

3. When placing the top course on paths eight feet (8’) in width or greater, the material shall be placed using a paver having an automatically controlled and activated screed ad strike-off assembly and corresponding grade referencing equipment as directed by the ENGINEER.

4. A tolerance of ± 20° F from the specified target placement temperature will be allowed.

Occasional loads slightly outside the ± 20° F may be permitted, provided that adjustments are being made to bring the temperature of the HMA mixture back to the specified target placement temperature.

5. Any load having a temperature below 250° F or above 350° F at time of discharge from the Hauling unit will be rejected.

Quality Control (QC)

1. The CONTRACTOR will be responsible for providing the QC for the HMA during production at no expense to the ENGINEER. Testing will be completed by individuals holding the following MDOT certifications: HMA or Bit Level 1 or HMA or Bit QC/QA.

2. The CONTRACTOR is responsible for providing a Quality Control Plan (QCP) for the HMA in accordance with the HMA Production manual at the time of submittal of the JMF. The CONTRACTOR is responsible for establishing a testing frequency. At a minimum, (1) set of tests will be taken per day of production. It is the responsibility of the CONTRACTOR to notify the ENGINEER of the QC tests results immediately upon completion. In the event the QC tests fail to meet specification, additional QC testing will be performed until the CONTRACTOR is able to demonstrate to the ENGINEER that the JMF is being maintained.

All QC test results must be provided to the ENGINEER no later than 3 business days after the date the tests were completed. All “failing” QC test results must be provided to the ENGINEER no later than the next business day.

3. At the direction of the ENGINEER, a maximum of 500 tons of each HMA mix type can be accepted by Visual Inspection (V.I.) per project (not per day).

4. Utilizing the appropriate ASTM or MTM Test Methods, the QC tests results will include and not be limited to the following:

Stability and Flow Bulk Specific Gravity Sieve Analysis and % Passing #200 Maximum Theoretical Specific Gravity % Crushed % of Recovered Asphalt % Air Voids

5. After the JMF is established, the aggregate gradation, crushed and bitumen content of the HMA mixture(s) furnished for the project shall be maintained within the Range 1 uniformity Tolerance limits permitted for the JMF as specified in Table 1 titled “Uniformity Tolerance Limits For HMA Mixtures” in the MDOT Special Provision For Acceptance of Hot Mix Asphalt Mixture On Local Agency Projects (12SP-501J-03).

If, however, the CONTRACTOR’s QC testing indicates that two (2) consecutive aggregate gradations on one (1) sieve, crushed or bitumen content(s) are outside of Range 1 but within Range 2 as shown in Table 1 of 12SP-501J-03, the CONTRACTOR shall suspend all operations. Contract time shall continue during these times when the HMA plant is down.

Before resuming production, the CONTRACTOR shall propose, for the ENGINEER’s approval, all necessary alterations to the materials or plant so that the JMF can be maintained. If the necessary alterations cannot be maintained, the ENGINEER may require a new JMF. If, in the ENGINEER’s judgement, the non-conforming mixture requires removal, the CONTRACTOR shall remove the mixture at their own expense and replace with a mixture meeting specification requirements. If, in the ENGINEER’s judgement the non-conforming mixture can remain in place, the unit price for the non-conforming mixture will be reduced according to the following schedule:

Non-Conforming Item Penalty Reduction per SYD

Asphalt Binder (minus) ....................................10% Asphalt Binder (plus) ......................................... 5% Each Sieve ......................................................... 5%

For any one (1) mixture, if the CONTRACTOR’s QC tests indicate (2) or more consecutive parameters, such as aggregate gradation on one (1) sieve, crushed or binder content exceed the uniformity tolerance of Range 2 shown in Table 1 of 12SP-501J-03, the mixture will be rejected. If in the ENGINEER’s judgement the defective areas warrant removal, the CONTRACTOR shall remove and replace the areas, at the CONTRACTOR’s expense, with mixtures meeting specification requirements. If in the ENGINEER’s judgement the defective material can remain in place the contract unit price for the material outside of Range 2 will be decreased by 15% for each parameter.

Rolling and Compacting

1. Each layer of the HMA shall be compacted to the required density with approved rollers. At least two rollers will be required when the lay-down rate exceeds 800 square yards per hour.

2. Steel three-wheel rollers may be used for initial paving immediately following the paving immediately following the paver.

3. The final rolling operation on each layer of HMA shall be accomplished by use of tandem steel-wheel rollers or by use of vibratory rollers operated in the static mode.

4. Roller wheels will be kept properly moistened with water.

5. Pneumatic-tired rollers will not be permitted on wearing courses.

6. Pneumatic-tired rollers shall be operated in a competent manner and shall not mark or rut surface or displace the pavement edge.

7. The pneumatic-tired roller shall be ballasted to obtain the required ground contact pressures as directed by the ENGINEER. In order to obtain a uniformly textured mat and the desired pavement density, the ENGINEER may direct the CONTRACTOR to raise or lower tire pressures at any time during the rolling operations. The roller operations shall be conducted in such a manner as to prevent scuffing or chatter marks in the pavement surface. The number of passes made by the pneumatic-tired roller shall not be less than two (2) round trip passes over each area.

Rolling of the mixture shall begin as soon after placing as it will bear the roller without undue displacement, picking up the mat or cracking. Rolling shall start longitudinally at the extreme sides of the lanes and proceed toward the center of the pavement, overlapping on

8. successive trips by at least half the width of the drive wheel of the roller. Alternate trips of the roller shall be of slightly different lengths. The maximum roller speed for the type of mixture or thickness of the layer being placed.

9. When compacting an adjoining lane, the longitudinal joint shall be rolled first with the roller supported mainly on the cold lane with only three-to-six inches (3-6”) of the roller extending onto the freshly placed HMA.

10. Finish rolling shall continue until all roller marks are eliminated.

11. Areas inaccessible to the standard eight (8) ton tandem rollers shall be compacted by self-propelled trench rollers of suitable width, approved by the ENGINEER, and weighing not less than 300 pounds per inch of width.

12. Skin patching will not be permitted on any area that has been rolled.

13. Any mixture that becomes mixed with foreign material or is any way defective shall be removed and replaced at the CONTRACTOR’s expense.

14. Rolling shall proceed continuously until the required compaction is obtained.

15. The measurement of field compacted density will be accomplished utilizing a nuclear density gauge. The percent (%) compaction shall be determined by using the Gmm from the JMF for the density control target. The required in place density of the HMA mixture must be 92.0 % to 96.0 % of the density control target.

16. Unless otherwise directed by the ENGINEER, field density tests utilizing the nuclear density gauge will be obtained at a frequency of one (1) test for every 250 lineal feet of paving lane (unit), except for the last unit which will be 250 lineal feet plus any fractional unit less than 125 lineal feet in length, or will be a fractional unit 125 lineal feet or more in length.

Miscellaneous areas such as intersections, crossovers and widened lanes less than 125 feet in length will be tested at the discretion of the ENGINEER.

17. Nuclear density tests will be taken on a random basis longitudinally within each unit and transversely within each unit. Tests will be taken at the discretion of the ENGINEER in areas that have received the least amount of compactive effort. Individual tests failing to meet the required in place density will be penalized as described below:

a. When individual density tests fail to meet 92.0 % to 96.0 % of the density control target as determined above, two (2) additional density tests will be taken in the 250 lineal foot pavement unit. The two (2) additional density tests will be taken at a minimum of 25 feet from the original test.

b. The average of the three (3) tests will be used to base the penalty and compute an adjusted price in accordance with the following schedule:

AVERAGE TEST RESULTS PRICE ADJUSTMENT per SYD

92.0% to 96.0% ...........................................................................100% 91.0% to 91.9% and 96.1% to 97.0% .......................................... 90% 90.0% to 90.9% and 97.1% to 98.0% .......................................... 80% 89.0% to 89.9% .............................................................................70% 88.0% to 88.9% and 98.1% to 99.0% ........................................... 50% Less than 88.0% and Greater than 99.0% ........... No Payment or Removal as Directed by the ENGINEER

The Square Yard’s (SYD) to be penalized will be computed by the ENGINEER based on the length of unit and width of paving lane.

Weather and Seasonal Limitations

1. HMA shall not be placed, nor the prime coat or bond coat applied when rain is threatening or when the moisture on the existing surface would prevent satisfactory bonding.

2. Unless otherwise approved by the ENGINEER in writing, temperature and seasonal requirements for placing hot mix asphalt shall be in accordance with the current MDOT standards.

3. HMA paving will not be allowed when there is frost in the grade.

Protection of Structures

Structures shall be protected to prevent their surfaces from being discolored during the application of HMA to the road surface.

Equipment

1. The CONTRACTOR shall furnish sufficient equipment for the placing of the hot mix asphalt.

2. The equipment shall be on the job site and ready for normal operation before the placing of material is started.

3. All equipment shall be in good working order.

4. The equipment shall be subject to inspections and testing during construction.

5. The equipment shall be of sufficient capacity that the operation can be continuous and a rate of production obtained which insures good workmanship and eliminates overloading of the equipment or frequent interruptions or delays.

6. The equipment shall conform to the requirements as specified in Division 5, Section 501 of the 2012 MDOT Standard Specifications.

A. Flasher Lights for Bituminous Concrete Equipment

• On HMA construction, where traffic is being maintained, chip spreaders, distributors and rollers shall be equipped with at least one (1) approved flashing, rotating or oscillating amber light, and pavers shall be equipped with at least one (1) such light on each side of the paver.

• The lights shall be mounted so that the warning signal will be visible to traffic in both directions. The lights shall be in operation all the while the work is in progress.

B. Hauling Equipment

• Trucks used for hauling hot mix asphalt shall have tight, clean, smooth beds that have been thinly coated with lime solution or other approved release agent to prevent the mixture from adhering to the beds.

• Each truck shall have an adequately secured cover of such size and material as to completely protect the mixture from the weather and to retard the escape of heat from the mixture.

C. Pressure Distributor

• The distributor shall be mounted upon a vehicle that is capable of maintaining the uniform speeds required for proper application of the hot mix asphalt.

• The vehicle shall be equipped with an accurate tachometer, which is calibrated to indicate speed in feet per minute.

• The pressure distributor shall have a capacity of at least 800 gallons.

• It shall be equipped with heating facilities capable of maintaining the hot mix asphalt at the specified temperature.

• A positive displacement-type pump, installed so as to permit circulation of the material in the tank and between the tank and the spray bar shall be provided.

• The pump power shall be independent of the vehicle power of the pump which shall be operated by a power take-off from the vehicle power motor in such a manner that uniform distribution of the hot mix asphalt at the rate specified will be obtained.

• The distributor shall be equipped with a tachometer calibrated in revolutions per minute or gallons per minute.

• Full circulating spray bars shall be available for application widths of three feet (3’) to 24 feet in one-foot (1’) increments.

• The nozzles shall produce a uniform fan spray, and the shutoff shall be instantaneous with no dripping. Nozzles in various sizes between one-eighth inch (1/8”) and one-quarter inch (¼”) inclusive shall be available.

• The spray bar shall be set at the proper height to provide a uniform application at the specified coverage rate.

D. Pavers

• The paver shall be an approved self-powered machine capable of spreading and finishing the mixture in a uniform layer at the desired thickness and cross section and ready for compaction.

• The use of any machine in poor mechanical or worn condition will not be permitted.

• The paver shall be of such design that the supporting wheels, treads or other devices ride on the prepared base.

• The full width of surface being applied shall be screeded by an oscillating or vibrating screed.

• The paver shall at all times produce a uniformly finished surface, free from tearing or other blemishes that would require hand work.

• The screed shall be adjustable to provide for tilting to secure the proper drag or compressive action necessary to produce the desired surface texture.

• The paver shall be equipped with a hopper and an automatic material-depth control device so that each distributing auger and corresponding feeder shall respond automatically to provide for a constant level of mix ahead of the screed unit to the full width of the lane being paved.

• In order to ensure that adequate material shall be fed to the center portion of the lane being paved, reverse pitch augers or paddles shall be installed at the inside of one or both ends of the auger shafts to force the mix to the middle portion of the lane.

• If necessary to prevent segregation of the mix as it drops of the feed conveyor, battle plates shall be installed at the required location.

• When extensions are added to the paver, they shall be provided with the same vibrating screed or tamper action as the main unit of the paver, except for paving variable width areas.

• The extensions also shall be equipped with a continuation of the automatically controlled spreading augers.

• The screed and any extensions shall be provided with an approved method of heat distribution.

• Unless specified otherwise, hot mix asphalt pavers shall be equipped with an automatically controlled and activated screed and strike-off assembly capable of grade reference and transverse slope control.

• A manufacturer approved grade referencing attachment, not less than 30 feet in length, shall be used for all lower courses and the first lane of the wearing course.

• After the first lane of the wearing course has been placed, a 10-foot or longer grade referencing attachment may be substituted for constructing subsequent adjacent lanes of wearing course.

• A self-propelled mechanical spreader capable of maintaining the proper width, depth, and slope without causing segregation of the material may be used for base courses and for surface courses less than eight feet (8’) in width.

• When surfacing ramps or shoulders, or when the grade of concrete gutter or other existing installation must be met, the manner of use or the automatic grade reference and slope control devices shall be determined by the

ENGINEER.

• Whenever a breakdown or malfunction of the automatic controls occurs, the equipment may be operated manually for the remainder of the normal working day, provided this method of operation will produce results meeting the specification requirements.

E. Mixers

• Mixers shall be self-propelled and a combination scarifier, pulverizer, mixer and liquid distributor. Unless otherwise specified, a minimum of two (2) mixers will be required.

• If hot mix asphalt is used as a stabilizer, one mixer shall be self-propelled single-pass stabilizer, combining a cutting rotor, a blending rotor and at least one mixing rotor in the mixing chamber.

• The spray bar for distribution of the liquid shall operate in such a manner that all asphalt will be uniformly applied through the mixer at the time of mixing.

• The equipment for distributing the bituminous material shall be adjustable and shall measure accurately the amounts of bituminous material being applied.

• The bitumen pump shall be a positive displacement type pump. It shall be equipped in such a manner as to make it possible to check accurately the rate of application of the bitumen at any time.

• The mixer shall meet the approval of the ENGINEER.

F. Joint Heaters

• Joint heaters shall be infrared or other approved heaters, equipped with automatic ignition and extinguishing system to ensure that the heater operates only when the paver is moving.

• It shall be of sufficient length and heating capacity to adequately soften the edge of the mat.

• The heater shall be oriented parallel to the joint edge.

• The hot mix asphalt shall not be heated by a direct open flame.

G. Rollers

• Steel-Wheel — Steel-Wheel rollers shall weigh at least eight (8) tons and shall be self-propelled, vibratory or static, tandem rollers or shall be self-propelled static three-wheel rollers.

a. Steel-wheel rollers shall be free from backlash, faulty steering mechanism, or worn king bolts.

b. The steering device shall respond readily and permit the roller to be directed on the alignment desired.

c. Rollers shall be equipped with wheel sprinklers and scrapers.

d. Roller wheels shall be smooth and free from openings or projections that will mar the surface of the pavement.

e. Vibratory rollers shall have a shutoff to deactivate the vibrators when the roller speed is less than 0.5 mph and shall have provisions to lock in the manufacturer’s recommended speed, the vibrations per minute, and the amplitude of vibration (Dynamic force) for the type of bituminous mixture being compacted.

• Pneumatic-Tired

a. The pneumatic-tired roller shall be of the self-propelled type with a total weight, including ballast, no greater than 30 tons.

b. It shall be equipped with a minimum of seven (7) wheels situated on the axles in such a way that the rear group of tires will not follow in the tracks of the forward group but will be so spaced that a minimum tire path overlap of one-half inch (½”) is obtained.

c. The tires shall be smooth and shall be capable of being inflated to or adapted to achieve a pressure necessary to provide ground-contact pressures of at least 80 pounds per square inch.

d. The tire pressures shall not vary by more than five (5) pounds per square inch between individual tires.

e. The CONTRACTOR shall furnish the ENGINEER charts or tabulations showing the contact areas and the contract pressures for the full range of tire inflation pressures and tire loadings for the type and size roller used.

f. The roller shall be equipped with a mechanism capable of reversing the motion of the roller smoothly.

g. The roller shall be equipped with wheel sprinklers and scrapers or mats.

H. Chip Spreader

• The chip spreader shall be self-propelled and shall be equipped with pneumatic tires.

• The spreader shall be equipped with a screen mounted below the metering gage.

HOT MIX ASPHALT (HMA) WEDGING

This work shall be in accordance with Division 2, Section 204 and Division 5, Sections 501and 502 of the 2012 MDOT Standard Specifications For Construction and the Specification for Hot Mix Asphalt (HMA).

Any possible inconsistencies that may exist between the requirements included herein, and the requirements of the «cntynam» or work under their jurisdiction, will be resolved by the ENGINEER at the time such inconsistency is identified.

The CONTRACTOR shall install the Hot Mix Asphalt (HMA) Wedging to the dimensions and thickness shown on the plans or as directed by the Engineer. Wedge with HMA to remove irregularities in the existing road. Place and compact HMA Wedging to correct the foundation. Allow the Wedging to cool enough to support construction equipment without causing visible distortion of the mat before placing subsequent Wedging, Base, Leveling or Top course mixtures.

Mixtures

The HMA Wedging Course Mixture shall be in accordance with the Specification for Hot Mix Asphalt (HMA) and as defined in the “Description” section of this Specification.

The HMA Wedging Course shall be a HMA 1100 T Mix. If approved by the ENGINEER, the HMA Top Course Mix specified for the project can be used in place of the HMA 1100 T Mix at no additional cost to the Owner. Under no circumstance will the HMA 1100 T Wedging Course be used as the HMA Top Course.

Date Published – 7/9/2024