SPECIFICATIONS:

SPECIFICATIONS
FOR HOT IN-PLACE ASPHALT SURFACE RECYCLING


SCOPE

The work covered by this section of the specifications consists of furnishing all labor, equipment, and materials, and performing all operations in connection with heating scarifying, leveling, compacting, applying a recycling agent, and placing an additional new asphalt surface.

VIEWING THE STREETS

Prior to bidding the job, the agency shall provide plans and specifications or a list of the streets to be recycled for the bidding contractors, to view the streets and become familiar with their condition. In contracts with optional annual extensions, the agency will again provide plans and specifications or a list of streets to be recycled for the contractor to view them and become familiar with their condition prior to accepting each annual extension.

LAB TESTING – General

All testing of the asphalt surfaces will be completed by the owner to determine the optimum quantity per unit of recycling agent, the depth of asphalt to be recycled and the required thickness of the new asphalt to be placed. This information will be given for each street area and made a part of the invitation for bidding documents.

Rejuvenating Agent

The Contractor shall use a 100% oil rejuvenator meeting the following specifications of Pavement Savers, Inc., PSI 540T (or equal).

TEST DESCRIPTION METHOD SPECIFICATIONS TYPICAL


VISCOSITY, CST # 60C
VISCOSITY, CST # 100C
VISCOSITY, SUS # 100F
FLASH, COC C(F)
SPECIFIC GRAVITY, 60/60F
DENSITY @ 15C, NG/DM3
POUNDS PER GALLON
TOTAL ACID NO. MG NOH/G
GLASS TRANSITIONS, TG, C
RTPO VISCOSITY RATIO, 60C D2872 1.13
ASPHALTENES, WT%
SATURATES, WT%
NAPHTHENE AROMATICS, WT%
POLAR AROMATICS, WT%


D445
D445
D2161
D92
D1250
D4052
D1250
D664

D2872
D4124
D4124
D4124
D4124
MIN


5.58

198(390)
0.9467
MAX


9.90


0.9692


28.8
7.23
450
210(420)
0.9626
0.9590
7.99
0.10
-64
1.13
0.0
27.6
62.6
9.8



The Contractor shall provide a one-pint sample of the recycling agent exactly as it will be sprayed during construction. The Contractor shall deliver the sample to the laboratory that provided the recycling agent determination.

The testing laboratory shall test the sample to determine compliance with their recommendations. The Contractor shall deliver subsequent samples until a sample is approved. The Contractor shall instruct the testing laboratory to forward approval of the sample along with test results on the sample. The test results shall include density of the diluted sample and the dilution ratio of the diluted sample.

All time required for testing, including the two days for Engineer review of the testing laboratory’s initial report for the recommended recycling agent, shall be included in the “Time for Completion” set forth in the General Specification of the contract documents.

All costs incurred for testing services required by the Subsection, shall be included in the bid item for asphalt surface recycling.

It is the agencies intention to raise the penetration and lower the viscosity of the recycled asphalt to minimum FDOT standards for new asphalt.

New Bituminous Concrete


The mix designs for the application of the new bituminous concrete layer will vary in accordance with the thickness of the bituminous concrete being laid.

The mix design of the new bituminous concrete surface, by owner, less than 1” shall have a maximum size aggregate of 3/8”.

The mix design of the new bituminous concrete surface, by owner, 1” or thicker shall have a maximum size aggregate of 5/8”.

Depth of the asphalt being recycled will vary in accordance with the thickness of the existing asphalt and other factors determined by the owner.

It is the owner’s intention to raise the penetration and lower the viscosity of the recycled asphalt to minimum FDOT standards for new asphalt.


EQUIPMENT

Heating Equipment

The equipment used to heat the asphalt surface shall fully meet the standards of the state and local Bureau of Air Pollution Control.

The heating system shall be
100% radiant, (no flame), and have the capability to evenly adjust the output from 40,000 to 100,000 BTU’s per hr. in each square foot of the chamber surface to allow the machine to be pre-adjusted for the various asphalt types and environmental conditions. The heat must be capable of heating to the full depth of the asphalt to be recycled so that only viscous shearing (having a heavy, gluey quality) occurs. Scarifiers or milling heads using carbide teeth will not be allowed.

The heating system must also be capable of turning instant “ON and OFF” and to heat in widths ranging from 2’, 4’, 6’, 8’ and 13’ depending on the widths that are being recycled.

The average temperature as measured by a thermometer located 18 inches from the pavement surface and 24 inches from the heater chamber shall not exceed 180° F. under wind of less than two miles per hour in velocity. Under no condition shall this temperature reading exceed an average 180° F. in the vicinity of plants either alive or not. In no case shall there be protruding flames. Any plants subject to temperature over 140° F. shall be sprayed with water such that they are damp during the period of high temperatures. There should be no damage to any vegetation or other objects adjacent or overhanging the surface that is being recycled. If for some unforeseen reason the property is damaged, it will be replaced by the contractor at no additional charge to the agency.

Recycling Machine

Immediately following the heating, the recycling machine shall be equipped with a rejuvenating spinner type applicator adjustable from .02 gallons per square yard to .15 gallons per square yard. The rate of application shall be determined by the engineer, based on preconstruction laboratory analysis and adjustments for varying field conditions.
(Spray type applicators will not be allowed). The recycler shall be equipped with a counter to verify gallons used each working day.

Immediately following the application of the rejuvenating agent, the Recycler shall have multiple rows of scarifying/mixing teeth. The scarifying/mixing teeth shall be designed in shape and adjustable in spring pressure in the field to provide purely viscous shearing (having a heavy, gluey quality) of the heated asphalt only. The tooth design must provide uninterrupted scarification contiguous to rigid structures to a depth up to 1 1/2 inches. Scratching, scraping or milling of the cooler asphalt in order to accomplish the required scarification depth because not enough heat was applied, shall not occur. Therefore, scarifiers or milling heads using carbide teeth will not be allowed.


Following the scarifying mixing teeth there shall be a spreading device with augers and a screed with capabilities for crown adjustment, and depth controls at both extremities. The augers shall be directionally reversible independently of each other. The recycler must be capable of recycling in widths of 2’, 4’, 6’, 8’ and 13’. Adjustments shall be made to provide a cross section that conforms to the pavement profile. The vibratory screed shall be heated with a thermostat control to maintain screed temperature between 275 and 325 degrees F and shall be equipped with adjustable end strike offs to move scarified material away from the gutter flags, adjustable from 1/2” to 1 1/2” deep and from 3” to 18”wide.

The surface is to be scarified to a depth of 1 inch. The depth will be checked by the contractor every 100 yards by probing the uncompacted mix behind the recycler screed in five locations, one on each outside edge, one on each side moving toward the center half of the way in, and a final probe in the middle. All five probes must average 1 inch.


Paving Equipment

Immediately behind the recycling machine and before the temperature of the recycled asphalt drops below 170° F, the new asphalt lift shall be installed.

The paving equipment for the new asphalt shall meet all the requirements to place the asphalt according to the standard practice in the industry.

Compacting Equipment


Following the placement of the new asphalt, the recycled and new asphalt shall be compacted by means of a combination rubber/steel wheeled roller or a steel wheeled roller and a rubber tired roller, each weighing a minimum of 5 tons.

CONSTRUCTION

Weather. Weather limitation for this work shall be a minimum of 35 degrees F. and rising. Ambient temperature does not play as much of a factor when Hot in-place asphalt surface recycling versus conventional paving. Attention is to be directed to the surface temperature of the pavement to be recycled. If the surface temperature is 50° F and rising, one can recycle. The contractor still has the responsibility to meet the minimum required temperature of the recycled and new asphalt before compaction. If the surface is below 50° F, but the ambient temperature is rising, the contractor can raise the temperature of the surface to be recycled to specification with the surface heaters.

Working Hours

Normal working hours are 7 a.m. to 5 p.m., Monday through Friday. Work on holidays, weekends, will only be done if determined necessary be the Engineer.

Traffic Control

  1. Temporary pavement markings shall conform to the Requirements of the Engineer or Designee.
  2. Maintenance of Traffic: Suitable methods shall be used by the contractor to protect the new asphalt surface from all types of vehicular traffic without damage. Opening to traffic does not constitute acceptance of work.
  3. The contractor will maintain at least one-way traffic and shall provide effective Traffic Control at all times. Two-Lane traffic shall be maintained wherever possible. Note: Payment for Traffic Control shall be included in the various unit price bid. No separate payment for traffic control will be made.
  4. No interruption of access to property shall be made unless prior arrangements acceptable to the occupant or owner of the affected property have been made and approved with the Engineer or Designee.
  5. The Contractor shall have at all times of operation a Certified Traffic Control Supervisor on site.

Execution

The contractor will notify the Engineer at least 48 hours prior to commencement of any recycling operation.


Cleaning

Prior to commencing the hot in-place asphalt surface recycling, the pavement shall be cleaned of all loose material. Power brooms shall be supplemented, when necessary, by hand brooming and such other tools, as required, to bring the surface to a clean, suitable condition, free of deleterious material. Any required patching work shall be completed prior to beginning the process.

In some hot-in-place asphalt surface recycling, pavements that have received prior treatments with special seal coatings, slurries or chip seals, may require removal of these contaminates, determined by the engineer prior to any hot surface treatment.

Painted lines that exist on the surface to be recycled, will interfere with the recycling process, and must be removed.

Heater/Scarifier Setup

A competent crew shall be provided. The heater/scarifier unit, and other heating units, shall be brought to full operation at a constant speed with all machine adjustments set for continuous operation by the Contractor. The heater/scarifier must be capable of heating the surface to the proper depth at a minimum travel rate of 15 feet per minute (F.P.M.) under normal working conditions. Only the last heater/scarifier shall do the scarifying.

The Contractor shall immediately thereafter accompany the Engineer and provide all work necessary for access of the Engineer to verify proper equipment operation. Specifically, side covers on the heaters shall be removed to allow viewing of the heating element.

The Contractor shall make any adjustments necessary to comply with the plans and specifications. If following adjustments, the proper depth of penetration cannot be achieved, or performance of equipment does not conform to plan and specifications, the operation or change in speed is subject to the same preceding requirements as for the initial setup.

Heater/Scarifier Operation

Heater elements shall be adjusted to meet the minimum performance requirements of Subsection 302-11.3.1. The heater / scarifier unit shall be operated at a constant speed, and the minimum depth of 1” or what is practical in accordance to the thickness of the asphalt to be recycled. Scarification will be deemed acceptable when the moving average of five consecutive measurements per hour (measured by a probe), one on each side, one each 1/4 of the way from the edge and one in the middle, indicates the required depth has been scarified.

In addition, the contractor shall periodically scrape off the recycled material to verify a black viscous material exists at the interface between the recycled asphalt and the asphalt below. Any kind of powdery material will not be accepted. The contractor shall have the proper gauges and asphalt shovel available for the inspector at all times.

The existing asphalt surface shall be heated from 6 to 12 inches wider than the width to be processed.

Surface asphalt concrete shall be loosened and displaced by the scarifying rakes through viscous shearing only.

The temperature of scarified material shall be a minimum of 225 degrees F. and shall not exceed 350 degrees F when measured immediately behind the screed.

Crown adjustment, depth control adjustments. Auger directional settings and edger adjustments shall be made to provide a cross-section that conforms to the pavement profile specified.

Heater/scarified surface recycled materials shall be immediately compacted. Where an overlay of new asphalt concrete is to placed immediately after surface recycling, rolling shall not be performed on the recycled surface. The new asphalt concrete shall be placed before the residual surface temperature falls below 170 degrees F.

If the new asphalt cannot be placed before the residual surface temperature falls below 170 degrees F., at that time it shall be rolled prior to the placing of the new material.

In all cases, asphalt concrete placed on the recycled surface shall be deposited, distributed and spread by a separate asphalt paving machine, independent and disconnected to the heater/scarifier unit, and shall be constructed in conformance with the standard practices in the industry.

When the recycled surface is exposed to traffic or left more than 24 hours after recycling, or where cleaning is required to remove foreign material or dust, a tack coat shall be provided in conformance with standard practices, or the cleaned surface could be brought back up to temperature of 170 degrees F. by means of a pre-heater.

The process shall produce a welded, longitudinal joint, the standing edge of the adjoining asphalt pavement shall be fully heated to a width of at least 2 inches beyond the width to be scarified and recycled.

In the past, under the standard practices in the Industry, there have been surface areas that have not been included in the recycling portion of the paving, such as the radius at intersections, cul-de-sacs, cross overs and other areas not practical for a recycling train. Rather than scarifying, contractors have been tacking and resurfacing or milling, tacking and resurfacing. This is no longer acceptable and these areas are to be Hot in-place recycled by means of a smaller, single machine that will heat the surface up to not less than 350°F. and before the temperature drops below 300°F. the surface shall be scarified to a depth reasonable to accept the rejuvenating agent, and recompacted.

These areas are to be recycled before the recycling is done by the recycling train.

Paving

Immediately following the recycling operation and before the residual surface temperature falls below 170 degrees F., a layer of new asphalt concrete, as specified by the Engineer, is to be placed over the recycled surface at the rate of not less than 50 lbs per square yard using a virgin asphalt mix with a maximum large size stone of 3/8 inch and shall be performed according to standard practices in the industry. Asphalt applied 1 inch or more will also be virgin, but will have a maximum largest stone size of 5/8”.

Finished Surface

The finished surface shall have a reasonable uniform texture and shall be within 1/4 inch of a true profile grade and shall have no deviation in excess of 1/4 inch from a straight edge applied to the pavement perpendicular to the centerline. Areas varying from a true surface in excess of the above stated tolerance may be acceptable without correction if the Engineer determines that they were caused by a pre-existing condition, which could not have reasonably been corrected. Any unsuitable texture or profile, as determined by the Engineer, shall be corrected by the Contractor at no additional compensation.


Adjustment of Existing Manhole Covers and Valve Boxes

Existing manholes, water valves boxes, junction boxes, etc., that do not conform to the finished pavement grades shall be adjusted using risers, by the contractor, as directed by the Engineer.

Cleanup

The Contractor will keep the work site free from accumulations of waste material, rubbish and debris from and about the work site as will as all tools, construction equipment, and machinery, and surplus materials, and will leave the site clean and ready for occupancy by the Agency. The Contractor will restore to their original condition those portions of the work site, such as staging and stockpile areas. This will include returning the area to the proper grade and slope as well as replacing sod, if so required by the Engineer.

MEASUREMENT AND PAYMENT


In-place hot asphalt surface recycled pavement will be paid for at the contract unit price per square yard. Such price will constitute full compensation for finishing and placing of materials required to complete the surface recycling, including the application of the recycling agent, and re-compaction, and for all labor, equipment, tools, testing services and incidentals needed to complete the work in conformity with the Plans and Specifications.

Measurements to determine the area to be paid for will be made in horizontal planes.

Payment for cold milling provides for all costs for removal of existing asphalt by cold milling an average depth of 0”-1-1/4” inch of asphalt. The price quoted shall be per sq. yd. of material removed to the specified thickness, and shall include all required labor, equipment, material handling of salvaged material, and disposal of unused material.

Recycling agent will be paid for at the contract unit price per gallon by checking the amount used by a counter on the recycler at the end of each working day. The unit price shall include full compensation for furnishing and applying the recycling agent.

The new asphalt will be paid for and delivered to the job site by the agent.

Warranty

The Contractor shall provide workmanship and labor warranty for a period of at least 12 months from the date of application. The material warranty shall be as offered by the manufacturer.