Generic Recycling Specifications at One and A Half Inch (1 1/2”)


The work covered by this section of the specifications consists of furnishing all labor, equipment, materials, traffic control, testing other then owner testing and performing all operations in connection with Hot in-place asphalt surface recycling, and placing of additional new asphalt surface if required.


Prior to bidding the job, the owner shall provide plans, specifications and test results from a list of the streets to be recycled for the bidding contractors, the contractor shall view the streets and become familiar with their condition. In contracts with optional annual extensions, the owner will again provide the same information from the roads to be recycled prior to accepting each annual extension.

The owner will provide the testing results of the roads to be recycled for depth and weight of the asphalt only with these bid documents, all other test required will be at the contractor’s expense.

Any additional testing of the asphalt is the responsibility of the contractor. Cost for any additional testing is to be included in the unit price for recycling.
The owner is requesting that all the roads in this proposal shall have a newly constructed finished surface of a minimum of 1-1/2 “compacted depth, it can consist of 100% recycled or a combination of recycled with new bituminous concrete, a minimum of 50% of the 1-1/2 “shall be 100% in-place recycled asphalt.

When using 100% hot in-place asphalt surface recycled asphalt or the combination of hot in-place asphalt surface recycled and additional new asphalt the federal highway formula of 1”+1”=2 1/2” will be used for total compacted depth, see attached two pages from the U.S. DEPARTMENT OF TRANSPORTATION Federal Highway Administration National Highway Institute Titled “Techniques for Pavement Rehabilitation”.

Example for the requirement equivalent to 1 1/2” of new bituminous asphalt:

Hot in-place asphalt surface Recycling 100% in place will require a minimum of 2” compacted recycled asphalt.

Hot in-place surface recycling in combination with the placement of new hot mix asphalt will require a minimum of 3/4” compacted in-place recycled asphalt with a minimum of 1/2” placement of new hot mix asphalt.

The owner has an annual contract for asphalt delivered to the job site, a copy of this contract will be given to the bidding contractor upon request, any asphalt required for this job is to come from this contract, the price charged to the contractor shall be the same as the price to the owner, the contractor shall include this price in the unit price for Hot in-place asphalt surface recycling, the owner will be reimbursed by the contractor by deducting such cost from the charges to the owner for the unit price for Hot in-place asphalt surface recycling.

Recycled asphalt shall be recycled to improve the condition to include raising the penetration to 35, lowering the viscosity of between 6000 and 12000 centrapoisen, obtaining a density of 92%, air voids of 4%, a minimum marshal stability of 1200, while maintaining a totally viscous sheared (having a heavy, gluey quality) material at the interface between the recycled asphalt and the un recycled asphalt below to insure a 100% homogenous bond. The bond shall meet a minimum value of 150 PSI in a shear test. This test shall be performed consistent with FDOT.

If a new asphalt surface layer is used it shall also be 100% homogeneously bonded to the recycled asphalt and pass the same test.

New Bituminous Concrete

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

The mix design of the new bituminous concrete surface for an application of less than 1” shall have a maximum size aggregate of 3/8”.

The mix design of the new bituminous concrete surface for an application of 1” or thicker shall have a maximum size aggregate of 5/8”.


Heating Equipment

The equipment used to heat the asphalt surface shall fully meet the standards of the Federal, State and Local Bureau of Air Pollution Control. No flame shall touch the surface of the asphalt being recycled. The heat must be capable of heating to the full depth of the asphalt to be recycled so that only viscous shearing occurs.

In no case shall there be flames protruding from furnace chambers. 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 by excessive heat, it will be replaced by the contractor at no additional charge to the agency.

Recycling Machine

Immediately following the heating, the recycling machine shall recycle the asphalt by penetrating to the required depth and adding the necessary rejuvenating agent and/or any other material, additional new asphalt can be applied at this time only to compensate for depressions, pot holes and the like which may be required to achieve the requirements of the owner, based on preconstruction laboratory analysis and adjustments for varying field conditions. The recycler shall be equipped with a counter to verify gallons of rejuvenating agent or other material used each working day.

Following the recycling of the asphalt it shall be spread by a spreading device with augers and a screed with capabilities for crown adjustment, and depth controls at both extremities 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°F and 325°F if a new asphalt lift is going to be applied the recycler 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 depth of the asphalt to be recycled will be determined before the start of the job to determine whether the 1-1/2” will be 100% recycled or a certain other depth less then the 1-1/2” that would also include additional new asphalt to reach the combined total of 1-1/2”. The depth will be checked by the inspector as much as every 100 yards by probing, the depth of the scarified asphalt will be determined when taking the combined measurement of five probes on the recycled mate before the new asphalt lift is installed if required, one on each side, one each 1/4 way from each side and one in the middle. The five measurements shall consist of the average thickness of what was determined to be recycled.

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 crumbled stone or powdery material will not be accepted. The contractor shall have the proper gauges and asphalt shovel available for the inspector at all times.

Paving Equipment for Additional New Asphalt to be Installed if Required

If additional new asphalt will be required to obtain the total 11/2” compacted thickness of new pavement surface, immediately following the recycling operation, before the recycled asphalt is compacted and the residual surface temperature falls below 170°F, a layer of new asphalt concrete is to be placed over the recycled surface by a D.O.T. approved paver. It shall be placed according to standard practices in the industry. Asphalt applied 1” or more may be installed separate of the recycling train at another time.


Following the final placement of the new asphalt mixture, the recycled and/or new asphalt mixture shall be compacted.



Weather limitation for this work shall be a minimum of 45°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 that the surface temperature of the pavement to be recycled is a minimum of 60°F. 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 7 p.m., Monday through Friday. Night work or work on holidays and/or weekends will only be done if determined necessary by the Engineer. There will be a separate pay item for this.

Traffic Control

A. Temporary pavement markings shall conform to the requirements of the Engineer or Designee.

B. 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.

C. 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 recycling unit price bid. No separate payment for Traffic Control will be made. If a police officer, scout car, etc. is required, then there will be a separate pay item for these.

D. 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.

E. The Contractor shall have at all times of operation a Certified Traffic Control Supervisor on site.


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


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 brooms and other such 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. There will be a separate pay item for this.

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, there will be a separate pay item for this.
All traffic lines that exist on the surface to be recycled will cause unnecessary pollution and must be removed. There is a separate pay item for this.

Hot In-Place Asphalt Surface Recycling Setup Test Strip

A competent crew shall be provided. The heater recycling 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. Only the last unit with heaters shall loosen the asphalt to be recycled.

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.

Hot In-Place Asphalt Surface Recycling Operation

Heater elements shall be adjusted to meet the minimum performance requirements above. The heater/recycling unit shall be operated at a constant speed, and the minimum depth of what is determined in accordance to the engineer.

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 crumbled stone or powdery material will not be accepted. The Contractor shall have the proper temperature gauges, asphalt probe and asphalt shovel.

The existing asphalt surface shall be heated from 3” to 6” inches wider than the width that is being recycled.

The temperature of recycled material shall be a minimum of 225°F and shall not exceed 350°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.

The hot asphalt recycled surface materials shall be immediately compacted.

Where an overlay of new asphalt concrete is 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°F then the recycled and new asphalt shall be compacted together.

If the new asphalt cannot be placed before the residual surface temperature falls below 170°F, then the recycled asphalt shall be compacted prior to the placing of the new asphalt.

In all cases, additional new asphalt concrete placed on the recycled surface shall be deposited, distributed and spread by an approved D.O.T. asphalt paving machine separate from the asphalt recycling machine allowing the inspector to make all the necessary measuring, testing and inspection to the recycled asphalt before any new asphalt is applied.

If the recycled asphalt surface is compacted and is exposed to traffic or left more than 24 hours, the pavement shall be cleaned and a tack coat shall be provided in conformance with standard practices, or in place of a tack coat the surface could be cleaned and brought back up to temperature of 170°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” beyond the width to be 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, crossovers and other areas not considered practical for a recycling train. Rather than recycling, 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 250°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 train recycles the straight areas.

Finished Surface

The finished surface shall have a reasonable uniform texture and shall be within 1/4” of a true profile grade and shall have no deviation in excess of 1/4” 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. There will be a separate pay item for each.


The Contractor will keep the work site free from accumulations of waste material, rubbish and debris from and about the work site as well as all tools, construction equipment and machinery, and surplus materials, and will leave the site clean and ready for use by the owner.


Hot In-Place 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 all materials required to complete the surface recycling to the total depth of 1-1/2”, including but not limited to the application of the rejuvenating agent, sand, installation of any new asphalt, 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.

Cold Milling

If required, cold milling will be performed in accordance to the standard practices in the industry and shall include all costs for removal of existing asphalt by cold milling an average depth of 0” to 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 and disposal of salvaged material and cleaning of the roadway. There will be a separate pay item for this.


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.

U.S. & Canada 1-800-677-9442
Phone: (321) 635-9500 ~ Fax: (321) 635-9555 ~ P.O. Box 1923 ~ Cocoa, Fl. 32923 ~


Training Course

Participant Notebook
Federal Highway Administration
National Highway Institute
Contract No. DOT-FH-11-9589
Prepared by ERES Consultants, Inc.
Champaign, IL 61820

3.3 Hot Process

The hot process for surface recycling uses
heat to soften the top one-inch, making it easier
to rework. Because this mixture is hot, material
can be added to it and mixed. This allows for a
number of corrective actions:

The corrected mixture may be immediately compacted
if no extra structural capacity is required.

Extra structural capacity can be added by several

Either of these methods will produce an acceptable
surface. When the two mixes are not mixed together,
some extra structural advantage can be obtained.
The one inch that has been recycled with a modifier
will provide a soft layer that can act as a stress
relieving layer. This layer reduced the rate at
which existing cracks in the old surface will reflect
through the new surface.

It is a commonly accepted rule of thumb that a one-inch
overlay over one inch of recycled material out performs
a 2.5 inch overlay.