4-66 Section 414 – Cold In -Place Recycling
414.01 DESCRIPTION . This work shall consist of cold in -place recycling (CIR) of the existing pavement surface, including milling bituminous pavement from the existing roadway, crushing or screening the existing bituminous pavement if needed, the addition of asphalt emulsion or foamed asphalt binder, Portland cement, and virgin aggregate, and mixing and repaving of the material to the depths, lines, and grades shown on the Plans. Excess recycled material not used in the CIR process will become the property and responsibility of the Contractor. 414.02 MATERIALS . Materials shall meet the requirements of the following subsections: Portland Cement ................................ ................................ ................................ ......... 701.02 Performance -Graded Asphalt Binder ................................ ................................ ......... 702.01 Anionic Emulsified Asphalt ................................ ................................ ....................... 702.02(a) Cationic Emulsified Asphalt ................................ ................................ ...................... 702.02(b) Aggregate f or Bituminous Concrete Mixtures ................................ ........................... 704.10 Recycled Asphalt Pavement ................................ ................................ ...................... 704.22(a) Water ................................ ................................ ................................ .......................... 745.01 Emulsified asphalt for CIR, when used, shall be type HFMS -2, HFMS -2h, HFMS -2s, CSS -1, CSS -1h, MS-2h, or as recommended by the Contractor as a result of the design criteria of this specification and approved by the Engineer. Foamed asphalt binder for CIR, w hen used, shall be unmodified and grade 58S -28, unless otherwise specified in the Contract. The CIR shall meet the gradation requirements of Table 414.02A for extracted aggregate ( AASHTO T 30 , dry) taken from the pulverized material. TABLE 414.02A – EXTRAC TED AGGREGATE GRADATION Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves 1-1/2 inch (37.5 mm) 100 1 inch (25.0 mm) 90 – 100 No. 4 (4.75 mm) 30 – 70 No. 200 ( 0.075 mm) 0 – 12
4-67 The CIR shall be free of any materials not generally considered to be asphalt pavement. If the processed
material does not meet the gradation requirements as specified, additional virgin aggregates shall be added at a rate such that the blended mixture con forms to the gradation requirements specified in Table 414.02A . Additional virgin aggregate shall meet the requirements of Subsection 704.10(a) and Subsection 704.10(b) , except that sand equivalent is not required. 414.03 EQUIPMENT .
a.General Requirem ents. The recycling equipment shall be capable of milling the existing roadway, sizing the resulting RAP, and mixing the RAP with the recycling agent and any additives stipulated in the mix design. The recycling equipment shall be capable of meeting the sp ecified sizing requirements with either the milling process or with additional sizing equipment. The recycling equipment shall be capable of producing a homogeneous recycled pavement mixture by mixing the RAP with the recycling agent, water, and any other additives, either in the milling machine housing or in an additional mixing chamber. The equipment used shall be capable of placing the recycled pavement mixture to the requirements provided herein and to the lines and grades shown on the Plans. Any additi onal equipment used by the Contract or beyond th at specified below shall be approved by the E ngineer based on its suitability to produce results meeting the specification requirements. For foamed asphalt applications, the equipment must accurately foam bituminous material, uniformly add specified water, and provide samples of the foamed bituminous material through a sampling nozzle.
b.Spreading of Dry Cement . Dry cement shall be spread on the existing asphalt pavement surface ahead of t he milling machine using either a cyclone or screw type calibrated spreader truck built to provide a consistent, accurate and uniform distribution of material. The equipment must apply the additive within a tolerance of ± 10% of the specified rate.
c.Spreading of Corrective Aggregate . Corrective aggregate shall be spread in consistent and uniform windrows using belly dump trucks or tailgated trucks with end dumps and spread to a uniform thickness with a motor grader or mechanical spreader in front of the milling machine.
d.Mainline Milling Machine . The Contractor shall furnish a self -propelled machine capable of milling the existing bituminous pavement to the depth shown on the Plans. The machine shall be equipped with standard automatic depth controls and must maintain a constant cutting depth and width. The primary cutting drum shall be a sufficient width to recycle the full lane in one pass. The machine shall be capable of producing the size of material required or additional crushing or screening sh all be used. A smaller milling machine may be used to mill shoulders and miscellaneous areas ahead of the primary milling machine to increase the recycle d width.
4-68 (e) Portable Mixing Unit . The unit shall be capable of producing a uniform, thoroughly mixe d, cold
mixed asphalt product. The material feed system to the mixing unit shall be equipped with a computer -controlled weigh bridge that will determine the mass of recycled material being deposited into the mixing unit prior to the addition of the emulsif ied or foamed asphalt. The scales shall be calibrated to the manufacturer’s tolerance at the start of the Contract. This mixing unit shall be of a dual shaft pugmill design, equipped with a metering device which will continuously meter and maintain the am ount of emulsified or foamed asphalt being added to the process to a tolerance of ± 0.25% of the total, by weight. The asphalt control unit shall be equipped with a flow meter and a total delivery meter. A positive displacement pump capable of accurately metering the required quantity of asphalt down to a rate of 4 gallons per minute into the recycled material is required. The pump shall be equipped with a positive interlock system that will shut off automatically when material is not present in the mixin g chamber. The unit shall be designed to either deposit the mixed product onto the roadway in a sized windrow or be capable of depositing the product directly into a paver hopper. If a foamed asphalt recycling agent is used, the system shall be equipped with a heating system capable of maintaining the temperature of asphalt flow components to maintain the required expansion ratio and half -life. The asphalt binder injection system sh all contain an independent pumping system and spray bar to regulate the application of foamed asphalt separate from the water used to increase moisture content for compaction. The additive system shall be computer controlled and the rate of addition of wat er into the hot asphalt binder shall be automatically kept at a constant percent by weight of asphalt binder. An inspection or test nozzle shall be fitted at one end of the spray bar to produce a representative sample of foamed asphalt binder.
f.Tankers . Tankers used to supply the recycling machine with bitumen shall have a capacity of at least 2,500 gallons. No leaking tankers will be permitted on the job site. In addition, each tanker shall be equipped with the following:
1.A thermometer to show the t emperature of the contents in the bottom third of the tank.
2.Insulation to retain heat.
3.A calibrated dipstick marked at intervals of no more than 25 gallons, for measuring the contents of the tank.
4-69 (g) Placing Equipment . Placing of the CIR shall b e accomplished with a self -propelled bituminous
paver. The CIR material shall be spread without segregation to the lines and grades shown on the Plans or as directed by the Engineer. The screed shall be controlled by electronic grade and cross - slope contro l. If a pick -up machine is used to feed a windrow of the bituminous material into the paver hopper, the pick -up machine shall be capable of picking up the entire windrow down to the underlying materials.
h.Compaction Equipment . The number, mass, and type of rollers shall be sufficient to obtain the required uniform density, full depth, while the mixture is in a workable condition. A rubber -tired roller shall perform the initial rolling after the emulsion initially breaks (indicated by color change from br own to black). At a minimum, the following rollers shall be used:
1.At least one double drum vibratory roller with a minimum weight of 10 tons.
2.At least one pneumatic -tired roller with a minimum weight of 22 tons. Rollers shall have a width of not less than 65 inches. Tires on pneumatic rollers shall be evenly inflated and matched in size and profile so as to maximize compactive effort. 414.04 CONSTRUCTION REQUIREMENTS .
a.General Requirements . For quantity calculation and construction purpose s, a Portland cement content of 1.0% was used to estimate the required Portland cement tonnage for this work. Agency personnel and equipment shall be allowed free and full access to the project site at no additional compensation due the Contractor to allo w for any and all sampling required to assess compliance with the provisions of this specification. The Contractor will afford the Agency all traffic control operations and provide means to extract samples as requested to achieve this effort. The residual asphalt and cement content used in production may vary throughout the project and be adjusted by the Contractor based on the results of QC testing or other variables as identified by the Agency or the Contractor to maintain an optimized finished product. Emulsion or foamed asphalt binder, water, processed bituminous pavement, virgin aggregate, and Portland cement shall be added in the proportions necessary to meet mix design requirements and verified by tank checks performed in accordance with the minimum quality control frequencies.
b.Design Criteria . The CIR shall meet the design criteria requirements of Table 414.04A , Table 414.04B , or Table 414.04C , as applicable for the type of asphalt being used.
4-70 Table 414.04a – Emulsified Asphalt Using The Mar Shall Stability Test
Criteria Test Method Requirement Ratio of residual asphalt to cement -- 3 to 1, min. Stability value, dry subset AASHTO T 245 1,500 lbf , min. Retained stability, wet/dry subsets AASHTO T 245 0.70, min. TABLE 414.04B – EMULSIFIED ASPHALT USING THE INDIRECT TENSILE STRENGTH TEST Criteria Test Method Requirement Ratio of residual asphalt to cement -- 3 to 1, min. Indirect tensile strength, dry subset AASHTO T 283 45 psi , min. Tensile strength ratio AASHTO T 283 0.70, min. TABLE 414.04C – FOAMED ASPHALT Criteria Test Method Requirement Ratio of residual asphalt to cement -- 3 to 1, min. Foamed asphalt expansion ratio -- 8 times , min. Foamed asphalt half -life -- 6.0 sec. , min. Indirect tensile strength, dry subset AASHTO T 283 45 psi , min. Tensile strength ratio AASHTO T 283 0.70, min.
4-71 (c) Mix Design . The Contractor shall develop a CIR mix design consisting of RAP, emulsified asphalt
or foamed asphalt, Portland cement, and blended aggregate if appropriate. To obtain material to conduct mix designing, the Contractor shall sample exi sting pavement to represent the recycled aggregates that would be expected to result from the milling process. A minimum of f our samples representative of the quarter points of the entire length of the project shall be taken . The Contractor shall develop and submit a material sampling plan for review and approval by the Agency a minimum of 5 working days prior to obtaining CIR m ix design samples. At a minimum, the sampling plan shall include the number of samples, location of samples, and the method of sampling and backfilling. The mix design shall also consider shoulder areas to be widened beyond existing edge of pavement such t hat the recycled bituminous pavement is full width to the lines and grades shown in the Plans. When emulsified asphalt is used, AASHTO PP 86 shall be the method used to develop a mix design in accordance with AASHTO MP 31 , except only meeting the specified design requirements in Table 414.04A or Table 414.04B , as applicable. The job mix formula (JMF) shall contain the percent passing each sieve, emulsified asphalt type and content as a percent of total CIR material, and cement content as a percent of total CIR material. When foamed asphalt is used, AASHTO PP 94 shall be the method used to develop a mix design in accordance with AASHTO MP 38 , except only meeting the specified mix design requirements in Table 414.04C . The job mix formula shall contain the per cent passing each sieve, foamed asphalt content as a percent of total CIR material, and cement content as a percent of total CIR material. A minimum of 10 working days shall be allowed for evaluation of the submitted mix design. A copy of all test data use d in developing the mix design, including graphs, shall be submitted with the mix design. The established job -mix formula is valid until a change is made in aggregate source, cement content, or emulsion source. No change in the job -mix formula may be made without the written approval of the Engineer. The Engineer may approve changes in the design’s job -mix formula or discontinue use of the design if placement, finishing, or compaction characteristics are determined to be unsatisfactory.
d.Removal of Exist ing Pavement . The existing pavement surface, including cracks, shall be visibly free from all foreign matter before recycling commences. The Contractor shall be responsible for removing any deleterious materials or crack sealants which may interfere with t he CIR process.
4-72 In areas of shoulder widening, if milling is conducted prior to CIR, and subgrade or native soils
are encounter ed, the removed material shall be considered waste and removed from the project using the appropriate pay item for excavatio n. If the shoulders or miscellaneous areas are milled in advance of CIR to increase the recycled width, the material will be deposited in advance of the CIR to be incorporated into the recycling. If during the CIR process, the milling head is regularly breaking through to the subbase soils, the process shall be adjusted in consultation with the engineer. If more than 5% of the recycled material is screened off as waste, the Contractor will be req uired to change the process to reduce the amount of oversized material being screened off as waste, with the approval of the Engineer.
e.Placing . The mix shall be paved full width, including shoulders where paved shoulders existed or where the shoulders are widened, to the specified grade and slope. The bituminous mixture shall be placed and finished with the specified equipment, shall be struck off in a uniform layer to the full width required and of such depth that each course, when compacted, shall have the required thickness, and shall conform to the grade and elevation specified. The finished surface shall be of uniform texture and evenness and shall not show tearing, shoving, or pulling of the mixture. In areas where irregularities or unavoidable obstacles make the use of mechanical placing and finishing equipment impracticable, the mixture shall be spread, raked, luted, and compacted by hand me thods. Longitudinal joints between successive reclamation passes shall overlap. The Contractor shall provide a sufficient number of mixing passes so that overlap is achieved. The Contractor shall sequence the operations in order to complete all recycling a nd paving activities across the full width of the roadway within the same work shift. Longitudinal cold joints are not allowed in the emulsified asphalt stabilized base.
f.Compaction . Compaction shall be performed while the emulsion or foamed asphalt is in a workable state. The CIR material shall be finished within a grade tolerance of ± 1/2 inch, provided that this deviation is not maintained for a distance longer than 50 feet, and provided that the required crown or superelevation is maintained.
4-73 Deviations in the finished surface shall not exceed ± 3/8 inch in any direction using a 10 foot
minimum straight edge. Any repairs required to correct surface deviations are at the Contractor’s expense using Agency approved material and methods. The CIR shall be compacted to 98% to 102% of the target maximum density (TMD). If two out of three consecutive density test results are outside of the allowable range, the Contractor will be required to construct a new test section to establish an updated TMD. If the Engineer determines that the TMD is apparently incorrect, as evidenced be being achieved with little or minim al compactive effort, then the Engineer will require a new test section to establish a new TMD.
g.Curing and Stability . The CIR may be opened to traffic after achieving the target density and after the material is determined to be stable by the Engineer. Hot mixed bituminous concrete pavements shall not be placed until the CIR material has been allowed to cure and the free moisture conte nt is reduced to a maximum of 1.5% every 1,000 feet per lane or as directed by the Engineer. The Engineer may waive the 1.5% free moisture content in such cases that the CIR has been open to a cure period of 14 days or more. The required density shall be a chieved and maintained until a wearing course pavement has been placed. Any additional compaction effort or repair of imperfections in the CIR material shall be performed as directed by the Engineer at no additional cost to the Agency. As an alternative for the purpose of protecting the CIR from damage due to traffic, the Engineer may approve the use of an emulsified asphalt fog seal after the placement of the CIR and prior to the placement of any hot mix bituminous pavement.
h.Weather and Seasonal Limita tions . CIR shall not be performed when the ambient air temperature is below 50°F, when the overnight temperatures are expected to be below 50°F, when the temperature of the existing roadway surface is below 50°F, when the weather is foggy or rainy, or when weather conditions or predicted weather conditions are such that proper mixing, spreading, and compacting of the recycled material cannot be accomplished. The placement of CIR shall not be performed prior to May 1st or after September 15th. When it is in the public interest for servicing traffic, the Engineer may adjust the ambient air or existing roadway surface temperature requirements or extend the dates of the recycling season.
4-74 414.05 Quality Control .
a.General Requirements . The Contractor shall be responsible for performing all process control and quality control sampling and testing and operate in accordance with an approved QC plan. Prior to performing any CIR production, the Engineer or the Contractor may request a pre -recycle conference to discuss the recycling schedule. The Contractor shall sample, test, and evaluate the CIR process in accordance with the procedures and minimum frequencies specified in Table 414.05A . TABLE 414.05A – MINIMUM QUALITY CONTROL FREQUENCIES Test or Action Frequency Test Method Density 1 per 1,000 feet per lane AASHTO T 355 or AASHTO T 343 Air temperature 4 per day at even intervals Verified thermometer Surface temperature At beginning and end of each day’s operation Verified thermometer Yield for cement and emulsion 2 per day at even intervals Tank check RAP moisture 1 per day AASHTO T 217 or AASHTO T 255 Aggregate moisture 1 per day AASHTO T 217 or AASHTO T 255 In-place moisture content 3 per day AASHTO T 217 , AASHTO T 255 , AASHTO T 310 , or ASTM D7830 Gradation and asphalt content of final product 1 per day AASHTO T 30 (dry), AASHTO T 164 , or AASHTO T 308 Density testing shall be the average of three points across the lane (transverse) for each testing locatio n. Gradation failures shall require the Contract or to take action to adjust the process to achieve compliant material. Additional virgin aggregate added to correct gradation shall meet the requirements of Subsection 704.10(a) and Subsection 704.10(b) , except that sand equivalent is not required.
4-75 Quality control records shall include all sampling events, testing events, and process changes with
accurate time and location data. The Contractor shall submit QC records and summaries to the Engineer by 1:00 p.m. on the next working day. The Contractor shall make all test results, including randomly sampled densities, available to the Engineer onsite and on request. The Contractor shall cease recycling operations whenever one of the following occurs:
1.The computed yield of each additive differs from the approved JMF by 10% or more.
2.The Contractor fails to follow the approved QC plan.
3.The finished product is visually segregated, unstable, or otherwise defective, as determined by the Engineer. Recycling operations shall not resume until the Contactor and the Agency agree on the corrective action to be taken.
b.Quality Control Plan . The Contractor shall submit a quality control plan (QC plan) to the Engineer a minimum of 14 calendar days prior to initiating CIR operations and shall not commence CIR operations until the QC plan is accepted by the Engineer. The QC plan shall address any items that affect the quality of the recycling process including, but not limited to, the following:
1.QC Plan Administrator . The QC plan administrator shall be identified in the QC plan and shall list their past experience on CIR projects. They shall:
a.Be a full -time employee of the Contractor or an indep endent consultant not involved with the acceptance activities of the project .
b.Have a minimum of four years of experience in quality control activities in construction operations .
c.Have full authority to institute actions necessary for successful implementation of the QC plan.
4-76 (2) Quality Control Technician . The quality control technicians (QCT) shall be responsible for
conducting quality control and inspection activities to im plement the QC plan. There may be more than one QCT on a project. They shall:
a.Be a full -time employee of the Contractor or an independent consultant with a minimum of two years of experience in quality control activities in field construction operations .
b.Have completed the requirements for the applicable testing by the Northeast Transportation Training and Certification Program (NETTCP) for Soils and Aggregate Inspector, or an equivalent regional program .
c.Have full authority to institute actions ne cessary for successful implementation of the QC plan.
3.Minimum Quality Control Parameters . Minimum quality control parameters are:
a.Methods to adhere to the JMF.
b.Mixing details, pugmill type, production rates, and material processing.
c.Make and t ype of pavers.
d.Make, type, of rollers, and their respective location within the paving train.
e.Process control testing and quality control testing. Daily QC testing results shall be submitted to the Engineer as requested and copies of all project QC t esting shall be submitted on such dates that a biweekly estimate from the Agency is intended to be processed.
f.Laydown operations, including procedures for mix design modification, avoiding recycling and curing in inclement weather, avoiding damage from haul trucks, material yield monitoring, methods to ensure that segregation is minimized, longitudinal joint construction, procedures to determine the maximum rolling and placing speeds based on field quality control, and achieving the best possible smoothn ess.
g.Methods for protecting the finished product from damage and procedures for any necessary corrective action.
4-77 h. Methods of grade checks.
i.Examples of QC plan and logbook forms.
j.Methods for calibration or verification of density gauge.
k.Stockpile management procedures.
c.Control Section . Control sections shall be con structed to establish the TMD at the beginning of the CIR, and through the project as needed. The Contractor shall construct a control section to assure the Engineer that t he Contractor’s equipment and procedures are suitable for the work specified and establish the target maximum density and moisture content. The rolling pattern shall be determined from buildup, when the density readings show an increase in dry density of l ess than 1 pcf for the final four roller passes of each roller. The average of a minimum of 10 tests taken throughout the control section after the buildup is complete shall be used to determine the TMD. If Agency personnel are available, their values shall be included in the average, or used to establish the density gauge offsets, as directed by the Engineer. The control section shall be full lane width and a minimum of 500 feet long, or as approved by the Engineer. No further recycling shall be perfor med until all aspects of the control section and the TMD are approved by the Engineer. The Contractor shall use the same equipment for building both the accepted test sections and performing the CIR work on the project unless equipment substitution is appr oved by the Engineer. The Engineer may require an additional test section and additional process control sampling to investigate the suitability of substituted or changed equipment. If the control section does not meet the requirements of this specificatio n, or the target density is not determined from buildup testing, then the Contractor shall modify the procedure and either construct another test section or reconstruct the original test section until suitable results are obtained.
4-78 414.06 METHOD OF MEASUREMENT . The quantity of Cold In -Place Recycling to be measured for
payment will be the number of square yards of existing pavement which has been recycled in an acceptable manner as determined by actual surface measurements of the le ngths and widths of the recycled area as shown on the Plans or as directed by the Engineer. No additional compensation will be made for overlapping areas. The quantity of Aggregate for CIR to be measured for payment will be the number of tons used in the complete and accepted work. The quantity of Portland Cement for CIR to be measured for payment will be the number of tons of material in place in the complete and accepted work, as determined from the load tickets or other method as approved by the Engineer . The quantity of Emulsified Asphalt for CIR and Foamed Asphalt for CIR to be measured for payment will be the number of hundredweight used in the completed and accepted work. 414.07 BASIS OF PAYMENT . The accepted quantity of Cold In -Place Recycling will be paid for at the Contract unit price per square yard. Payment will be full compensation for performing the work specified including removal of deleterious material and crack sealant, and for furnishing all labor, materials, tools, equipment, and inc identals necessary to complete the work. Any additional RAP material, not generated from the project, required to meet the project volume of Cold In -Place Recycling will not be paid for separately but will be considered incidental to Cold In -Place Recyclin g. Any mainline milling prior to the CIR process will be paid for under the appropriate Section 210 pay item included in the Contract. The accepted quantity of Aggregate for CIR will be paid for at the Contract unit price per ton. Payment will be full com pensation for furnishing and placing the material specified and for furnishing all labor, tools, equipment, and incidentals necessary to complete the work. Payment for the furnishing of emulsified asphalt fog seal will be made under the appropriate Section 404 pay item in the Contract. The accepted quantity of Portland Cement for CIR will be paid for at the Contract unit price per ton. Payment will be full compensation for furnishing and placing the material specified and for furnishing all labor, tools, e quipment, and incidentals necessary to complete the work. The accepted quantity of Emulsified Asphalt for CIR and Foamed Asphalt for CIR will be paid for at the Contract unit price per hundredweight for the specified material applied. Payment will be full compensation for furnishing, transporting, and placing the material and for furnishing all labor, tools, equipment, and incidentals necessary to complete the work.
4-79 Payment will be made under:
Pay Item Pay Unit 414.0200 Cold In -Place Recycling, 2 Inch Depth ................................ .................... Square Yard 414.0250 Cold In -Place Recycling, 2.5 Inch Depth ................................ ................. Square Yard 414.0300 Cold In -Place Recycling, 3 Inch Depth ................................ .................... Square Yard 414.0350 Cold In -Place Recycling, 3.5 Inch Depth ................................ ................. Square Yard 414.0400 Cold In -Place Recycling, 4 Inch Depth ................................ .................... Square Yard 414.0450 Cold In -Place Recycling, 4.5 Inch Depth ................................ ................. Square Yard 414.0500 Cold In -Place Recycling, 5 Inch Depth ................................ .................... Square Yard 414.5100 Aggregate for CIR ................................ ................................ ..................... Ton 414.5200 Portland Cement for CIR ................................ ................................ .......... Ton 414.5300 Emulsified Asph alt for CIR ................................ ................................ ......Hundredweight 414.5400 Foamed Asphalt for CIR ................................ ................................ ........... Hundredweight
4-80 Section 415 – Cold Central Plant Recycling
415.01 DESCRIPTION . This work shall consist of cold central plant recycling (CCPR) of the existing pavement surface, including generating RAP material from the project or other sources, adding additional asphalt emulsion or foamed asphalt binder, Portland cement, virgin aggregate, and mixing and repaving of the material to the depths, lines, an d grades shown on the Plans. Excess recycled material not used in the CCPR process will become the property and responsibility of the Contractor. 415.02 MATERIALS . Materials shall meet the requirements of the following subsections: Portland Cement ................................ ................................ ................................ ......... 701.02 Performance -Graded Asphalt Binder ................................ ................................ ......... 702.01 Anionic Emulsified Asphalt ................................ ................................ ....................... 702.02(a) Cationic Emulsified Asphalt ................................ ................................ ...................... 702.02(b) Aggregate for Bituminous Concrete Mixtures ................................ ........................... 704.10 Recycled Asphalt Pavement ................................ ................................ ...................... 704.22(a) Water ................................ ................................ ................................ .......................... 745.01 Emulsified asphalt for CCPR, when used, shall be type HFMS -2, HFMS -2h, HFMS -2s, CSS -1, CSS -1h, MS-2h, or as recommended by the Contractor as a result of the design criteria of this specification and approved by the Engineer. Foamed asphalt binder for CCPR, when used, shall be unmodified and grade 58S -28, unless otherwise specified in the Contract. The CCPR shall meet the gradation requirements of Table 415.0 2A for extracted aggregate ( AASHTO T 30, dry) taken from the pulverized material. TABLE 415.02A – EXTRACTED AGGREGATE GRADATION Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves 1-1/2 inch (37.5 mm) 100 1 inch (25.0 mm) 90 – 100 No. 4 (4.75 mm) 30 – 70 No. 200 ( 0.075 mm) 0 – 12
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 384–397 of 1,380.