316 Any adjustm ent in compensation made for bituminous material incorporated into the work after the expiration of the specified completion time set forth in the contract, or as may be extended in accordance with the provisions of Subsection 108.08 of the specifications, will be on the basis of the price of bituminous material shown on the Department’s website and applicable for the date of the expiration of the specified completion time as hereinbefore specified. SECTION 406 BLANK: SECTION 407 ASPHALTIC CONCRETE FRICTION COURSE : 407- 1 Description: The work under this section shall consist of constructing Asphaltic Concrete Friction Course, hereinafter asphaltic concrete, by furnishing all materials, mixing at a plant, hauling and placing a mixture of aggregate materials, mineral admixture, and bituminous material (asphalt cement) to form a pavement course or to be used for other specified purposes, in accordance with the details shown on the project plans and the requirements of the specifications, and as directed by the Engineer. 407- 2 Asphaltic Concrete Mix Design: Mix designs will be developed on the basis of and tested in accordance with the requirements of Arizona Test Method 814. The allowable range of percent absorbed asphalt shall be 0- 1.0, when tested in accordance with Arizona Test Method 806. 407- 3 Materials: 407- 3.01 Mineral Aggregate: The contractor shall provide a source of mineral aggregate in accordance with the requirements of Section 1001 of the specifications. When the contractor selects a source or sources, it shall notify the Engineer. The contractor shall be solely responsible for assuring that the mineral aggregate meets all requirements and, when processed, is fully capable of providing asphaltic concrete which meets all the requirements of these specifications. TABLE OF CONTENTS INDEX 317 Mineral aggregate shall be separated into at least two stockpiles. No individual stockpile or hot bin usage shall be less than 3 percent of the total mineral aggregate. Coarse mineral aggregate shall consist of crushed gravel, crushed rock, or other approved inert materials with similar characteristics, or a combination thereof, conforming to the requirements of these specifications. Fine mineral aggregate or blend material shall consist of natural sand, sand prepared from rock, or other approved inert materials, or a combination thereof, conforming to the requirements of these specifications. Mineral aggregate furnished for mix designs shall be representative of the source(s) and sampled from the material stockpiles to be used in asphaltic concrete production. Mix designs shall conform to the grading limits in Table 407- 1, when tested in accordance with Arizona Test Method 201. TABLE 407 -1 MIX DESIGN GRADING LIMITS Sieve Size Percen t Passing Without Admixture With Admixture 3/8 Inch 100 100 No. 4 35 – 55 36 – 55 No. 8 9 – 14 10 – 15 No. 200 0 – 2.0 0 – 3.0
Mineral aggregate shall conform to the requirements in Table 407- 2 when tested in accordance with the applicable test methods. Tests on aggregates outlined in Table 407- 2, other than abrasion, shall be performed on materials furnished for mix design purposes and composited to the mix design gradation. Abrasion shall be performed separately on samples from each source of mineral aggregate. All sources shall meet the requirements for abrasion. TABLE OF CONTENTS INDEX 318 TABLE 407 -2 MINERAL AGGREGATE CHARACTERISTICS Characteristic Test Method Requirement Combined Bulk Oven Dry Specific Gravity Arizona Test Method 251 2.350 – 2.850 Combined Water Absorption Arizona Test Method 251 0 – 2.5% Sand Equivalent Arizona Test Method 242 (After thoroughly sieving the sample, no additional cleaning of the fines from the plus No. 8 material is required.) Minimum 55 Fractured Coarse Aggregate Particles Arizona Test Method 212 Minimum 85% (at least two fractured faces) and minimum 92% (at least one fractured face) Flakiness Index Arizona Test Method 233 Maximum 25% Carbonates Arizona Test Method 238 Maximum 20% Abrasion AASHTO T 96 100 Rev., Max. 9% 500 Rev., Max. 40%
407- 3.02 Mineral Admixture: Mineral admixture will be required. The amount used shall be 1.0 percent, by weight of the mineral aggregate. Mineral admixture shall be either Portland cement, blended hydraulic cement, or hydrated lime conforming to the requirements of Table 407- 3. TABLE 407 -3 MINERAL ADMIXTURE Material Requirement Portland Cement, Type I or II ASTM C150 Blended Hydraulic Cement, Type IP ASTM C595 Hydrated Lime ASTM C1097
Certification and acceptance of Portland cement, blended hydraulic cement, and hydrated lime shall be in accordance with ADOT Materials Practice and Procedure Directive No. 13, "Certification and Acceptance of Hydraulic Cement, Fly Ash, Natural Pozzolan, Silica Fume, and Lime". 407- 3.03 Bituminous Material: Asphalt cement shall be a performance grade (PG) asphalt binder, conforming t o the requirements of Section 1005 of the specifications. The type of asphalt binder shall be as shown in the Special Provisions. The percent of asphalt cement used shall be based on the weight of total mix (asphalt cement, mineral aggregate, and mineral admixture). TABLE OF CONTENTS INDEX 319 The percent of asphalt cement to be used will be specified by the Engineer. 407- 4 Mix Design: Approximately 300 pounds of produced mineral aggregate, in proportion to the anticipated percent usage, shall be obtained by the contractor and witnessed by the Engineer so that both parties are satisfied that samples are representative of the mineral aggregate to be utilized in the asphaltic concrete production. In addition to the mineral aggregate samples, the contractor shall also furnish the Engineer with representative samples of the following materials: 3 gallons of asphalt cement from the intended supplier, and a 1-gallon can of the proposed mineral admixture. These materials must be representative of the material which will subsequently be used in the production of asphaltic concrete. If the mineral aggregate does not meet the requirements of Subsection 407-3.01 of the specifications, no mix design will be prepared. The contractor shall take the necessary steps to provide material meeting the specified requirements. Along with the samples furnished for mix design testing, the contractor shall submit a letter explaining in detail its methods of producing mineral aggregate including wasting, washing, blending, proportioning, etc., and any special or limiting conditions it may propose. The contractor’s letter shall also state the source(s) of mineral aggregate, the source and type of asphalt cement, and the source and type of mineral admixture. Within 10 working days of receipt of all samples and the contractor's letter in the Central Laboratory, the Department will provide the contractor with a mix design containing the type, source, and percentage of asphalt cement; the type, source, and percentage of mineral admixture; the source(s) of mineral aggregate and the percentage from each stockpile; the composite mineral aggregate gradation; the combined mineral aggregat e and mineral admixture gradation; and any special or limiting conditions. The contract time established for the completion of the work includes 10 working days for the required testing and the developing of the approved mix design. Asphaltic concrete friction course production shall not begin until there is an approved mix design. The contractor may propose the use of a mix design that has been developed for a previous project. The proposed mix design shall meet the requirements of these specifications. The contractor shall provide evidence that the type and source of bituminous material, the type of mineral admixture, and the source and methods of producing mineral TABLE OF CONTENTS INDEX 320 aggregate have not changed since the formulation of the previous mix design. The contract or shall also provide current test results for all specified characteristics of the mineral aggregate proposed for use. The Engineer will determine if the previously used mix design is suitable for the intended use and if the previous use of the mix desig n was satisfactory to the Department. The Engineer will either approve or disapprove the proposed mix design. Should the Engineer disapprove the use of the previously used mix design, the contractor shall prepare and submit a new mix design proposal in a ccordance with the requirements of these specifications. A previously used mix design older than two years from the date it was formulated, sealed, signed, and dated shall not be allowed for use. Once approved for use on a project, a mix design may be used for the duration of the project. 407- 5 Mix Design Revisions: At any time after production of asphaltic concrete has been started using the approved mix design, changes may be proposed by the contractor or directed by the Engineer. The contractor shall not change its methods of crushing, screening, washing, or stockpiling from those used during production of material used for mix design purposes without approval of the Engineer, or without requesting a new mix design. If the contractor elects to change its source or type of bituminous material, the type of mineral admixture, or the source(s) of mineral aggregate, or if the contractor adds or deletes the use of a mineral aggregate stockpile(s) regardless of source, testing to the extent deemed necessary by t he Engineer will be performed in order that the Engineer may be satisfied that the mix design criteria will be met. Durin g production of asphaltic concrete the contractor, on the basis of field test results, may request a change to the approved mix design. The Engineer will evaluate the proposed changes and notify the contractor of the Engineer’s decision within two working days of the receipt of the request. If, at any time, unapproved changes are made by the contractor in the source or type of bituminous material, source(s) of mineral aggregate, production methods, or proportional changes in violation of approved mix desig n stipulations, production shall cease until a new mix design is developed at no additional cost to the Department, or the contractor complies with the approved mix design. At any time after the mix design has been approved, the contractor may request a new mix design. The costs associated with the testing of materials in the developing of mix designs requested by the contractor TABLE OF CONTENTS INDEX 321 after a mix design acceptable to the Department has been developed shall be borne by the contractor. If the Engineer determines t hat a new mix design is necessary due to changes in mineral aggregate characteristics or gradation, costs associated with the development of the new mix design shall be borne by the contractor. A new mix design can be developed by the Engineer at any time the Engineer deems necessary. Should such a new mix design require revisions to the contractor's operations which result in additional cost to the contractor, it will be reimbursed for these costs. However, the Engineer reserves the right to modify the a sphalt cement content without compensation being made to the contractor involving additional operation costs. 407- 6 Acceptance of Materials: 407- 6.01 General: The contractor's attention is directed to the requirements of Subsection 105.13 of the specifications. If the production of asphaltic concrete is stopped either for failure to meet the requirements specified in Subsection 407- 6.03 of the specifications or because changes are made in the mix design, samples will be taken for calculating new consecutive averages either after production resumes or after the changes in the mix design have been made. The acceptance of the mineral aggregate gradation and the bituminous material content will be determined on the basis of the tests as specified in Subsection 407- 6.03 of the specifications. The Engineer reserves the right to increase the frequency of sampling and testing upon the resumption of asphaltic concrete production. 407- 6.02 Mineral Aggregate: Aggregate shall be free of deleterious materials, clay balls, and adhering films or other material that prevent thorough coating of the aggregate with the bituminous material. Prior to and during asphaltic concrete production, the Engineer shall obtain and test samples of mineral aggregate for determination of the sand equivalent, fractured coarse aggregate particles, and flakiness index. Samples shall be obtained from the cold feed belt prior to the addition of mineral admixture, or from the stockpiles when sampling from the cold feed belt is not possible. Shoul d such testing indicate results not meeting the requirements of Table 407- 2 for sand equivalent, fractured coarse aggregate particles, and flakiness index, operations shall cease and the contractor shall have the option of requesting a new mix design or correcting deficiencies in the aggregate stockpiles. TABLE OF CONTENTS INDEX 322 407- 6.03 Asphaltic Concrete:
Prior to the initial startup of asphaltic concrete production, and prior to startup after any subsequent mix design revisions affecting gradation, a sample of the combined mineral aggregate shall be tested. The mineral aggregate shall meet the gradation r equirements for the three consecutive test limits indicated below. If the mineral aggregate does not meet these requirements, production shall not begin until the mineral aggregate is in compliance with this requirement. For each approximate 500 tons of asphaltic concrete produced, at least one sample of mineral aggregate will be taken. Samples will be taken in accordance with the requirements of Arizona Test Method 105 on a random basis. For batch plants, the sample shall be taken from the hot bins. For plants other than batch plants, the sample shall be taken from the cold feed belt. Samples will be taken by means of a sampling device which is capable of obtaining representative samples. The device, which shall be approved by the Engineer, shall be furnished by the contractor. In any shift that the production of asphaltic concrete is less than 500 tons, at least one sample will be taken. Samples will be tested for conformance to the mix design gradation, with or without mineral admixture as appropriate, in accordance with the requirements of Arizona Test Method 201. The gradation will be considered to be acceptable unless the average of any three consecutive tests or the result of any single test varies from the mix design gradation percentages as follows: Passing Sieve Number of Tests Three Consecutive One No. 4 ± 4 ± 6 No. 8 ± 4 ± 6 No. 200 ± 1.5 ± 2.0
One hundred percent of the material shall pass the 3/8- inch sieve. At any time that test results indicate that the gradation does not fall within all of the limits indicated, the production of asphaltic concrete shall cease immediately and shall not begin again until a calibration test indicates that the gradation is within the three consecutive test limits indicated.
During production of asphaltic concrete, the contractor shall maintain at the plant site a nuclear asphalt content gauge calibrated and operated in accordance with Arizona Test M ethod 421. At the discretion of the Engineer, the Department may choose to prepare the calibration samples TABLE OF CONTENTS INDEX 323 for use by the contractor. Under the observation of the Engineer, the contractor shall determine the asphalt content by means of the nuclear asphal t content gauge a minimum of four times per full shift. The Engineer shall determine the times that the samples are taken. The contractor’s technicians performing the testing, including the calibration of the nuclear gauge, shall meet the technician requirements given in ADOT Materials Practice and Procedure Directive No. 19, “ADOT System for the Evaluation of Testing Laboratories”. Production of asphaltic concrete shall cease immediately and the plant and/or the nuclear asphalt content gauge re- calibrated if any single test result varies by an amount greater than ± 0.60, or the average of three consecutive test results varies by an amount greater than ± 0.40, from the amount directed by the E ngineer. Material that has already been produced may be used on the project if the single test value representative of that material varies by an amount from ± 0.61 to ± 0.75, inclusive, from the amount directed by the Engineer. Material that has already been produced may not be used on the project if the single test value representative of that material varies by an amount greater than ± 0.75 from the amount directed by the Engineer unless, by retesting, the material is found to be acceptable. 407- 6.04 Material Spread: The estimated target spread rate will be as shown in the table in Subsection 407- 3 of the specifications. The Engineer may adjust the estimated target spread rate, and establish a new target spread rate, as necessary to maintain a suitable thickness. The thickness behind the screed shall be measured by the contractor continuously throughout each spread lot to ensure that the minimum compacted thickness specified in Subsection 407 -3 of the specifications is being met. A spread lot shall be considered to be one- half shift of production. The contractor shall record information pertaining to each spread lot on forms provided by the Engineer. Information shall include the project number, date and period of time that each spread lot was placed, the spread lot number, beginning and ending station, the plans thickness, target spread rate, and tons placed in each spread lot. Completed spread lot forms shall be signed by the contractor and given to the Engineer at the end of each shift. The Engineer will calculate the quantity required in each spread lot using the target spread rate. The calculated quantity required in each spread lot will be compared to the actual quantity placed. A spread lot will be considered to be acceptable if the actual quantity placed does not vary by more than +5.0 percent from the required quantity. TABLE OF CONTENTS INDEX 324 407- 7 Construction Requirements: 407- 7.01 Quality Control: Quality control of mineral aggregate production and asphaltic concrete production shall be the responsibility of the contractor. The contractor shall perform sufficient testing to assure that mineral aggregate and asphaltic concrete are produced which meet all specified requirements. The Engineer reserves the right to obtain samples of any portion of any material at any point of the operations for the Engineer’s own use. 407- 7.02 Stockpiling: The contractor will not be allowed to feed the hot plant from stockpiles containing less than two full days of production unless only two days production remain to be done or special conditions exist where the Engineer deems this requirement waived. Mineral aggregate shall be separated and stockpiled so that segregation is minimized. An approved divider of sufficient size to prevent intermingling of stockpiles shall be provided. 407- 7.03 Proportioning, Drying, Heating, and Mixing: The asphaltic concrete hot plant shall conform to the requirements of Section 403 of the specifications. Unless approved by the Engineer, no individual mineral aggregate stockpile or hot bin usage shall be less than 3 percent of the total mineral aggregate. No fine material which has been collected in the dust collection system shall be returned to the mixture unless the collected fines are accurately and uniformly metered into the mixture. The moisture content of the asphaltic concrete shall not exceed 0.5 percent. The moisture content w ill be determined in accordance with the requirements of Arizona Test Method 406. The temperature of asphaltic concrete or mineral aggregate upon discharge from the dryer shall not exceed 275 degrees F (325 degrees F when PG TR+ asphalt cement is used), unless otherwise approved by the Engineer. TABLE OF CONTENTS INDEX 325 407- 7.04 Placing and Finishing:
The handling of asphaltic concrete shall at all times be such as to minimize segregation. Any asphaltic concrete which displays segregation shall be removed and replaced. All wheels and tires of compactors shall be wetted with water, or if necessary soapy water, or a release agent in order to prevent the sticking of asphaltic concrete. All other equipment surfaces shall be treated when necessary with a release agent. Only release agents evaluated through NTPEP are acceptable for use. The results from NTPEP testing, when tested i n accordance with AASHTO TP 102, shall meet the following criteria: RELEASE AGENT TEST REQUIREMENT Asphalt Stripping Test Diluted Non -Diluted (Full Strength) No Stripping No Stripping Mixture Slide Test 10 g Retained, Max. Asphalt Performance Test Less than or equal to 10.0% after the third cycle
Release agents which degrade, dissolve, or in any way damage the bituminous material shall not be used. Diesel fuel shall not be used as a release agent. Before asphaltic concrete is placed, the surface to be paved shall be cleaned of all objectionable material and tacked with bituminous material in accordance with the requirements of Section 404 of the specifications. Unless otherwise specified on the project plans, asphaltic concrete shall not be placed on the 2-foot widened section where guardrail is to be installed.
Asphaltic concrete shall be placed when the temperature of the surface on which the asphaltic concrete is to be placed is at least 85 degrees F and the ambient temperature at the beginning of placement is at least 70 degrees F and rising. The placement shall be stopped when the ambient temperature is 75 degrees F or less and falling. Night time placement may occur during falling temperature if the low temperature is 70 degrees F or higher. No placement of asphaltic concrete shall occur if ambient temperatures are forecasted to be at or below 40 degrees F at an y time during the day or night after placement. TABLE OF CONTENTS INDEX 326 No placement of asphaltic concrete shall occur if ambient temperatures exceed, or are forecasted to exceed, 110 degrees F the day before, the day of, or the day after paving. No placement of asphaltic concret e shall occur if sustained wind speeds in excess of 15 MPH are forecast on the day of the scheduled placement. However, the Engineer may allow placement of asphaltic concrete during high wind conditions if the ambient temperature is 85 degrees F and risin g. No asphaltic concrete placement shall take place if rain occurs at any time in the two days prior to the scheduled placement of the asphaltic concrete, nor shall placement be expected to occur if rain is forecast during the proposed day of placement. H owever, at the discretion of the Engineer, placement may commence if actual conditions are conducive to placement. At any time, the Engineer may require that the work cease or that the work day be reduced in the event that weather conditions are anticipated to have an adverse effect upon the asphaltic concrete. Unless otherwise directed by the Engineer, no traffic (including construction traffic, with the exception of required striping equipment) shall be allowed on the AR -ACFC overlay until at least eig ht hours after the placement of AR -ACFC. The Engineer may reduce this time for materials placed on ramps and auxiliary lanes, or for traffic related purposes. Prior to opening to any traffic, the Engineer may require up to three applications of lime water (a minimum of 50 pounds of lime per 2,000 gallons of water). Reasons may include, but are not limited to, opening prior to the eight hour curing time, or ambient temperatures above 100 degrees F. Lime water shall be applied in a manner that uniformly covers the entire surface of the paving pass. No separate payment will be made for lime water or its application, the cost being considered as included in this contract item. The contractor shall prepare their bid submittal and initial construction schedule, submitted at the Preconstruction Conference as described in Subsection 108.03 of the specifications, based on the following beginning and ending dates for asphaltic concrete production. Average Elevation of Project, Feet Beginning and Ending Dates 0 – 3499 0 – 3499 3500 – 4999 5000 – 5999 6000 and over March 15 – May 31 September 1 – October 31 April 15 – October 15 June 1 – September 15 June 1 – August 15
Any proposed placement deviating from the beginning and ending days shall be detailed in the written schedule of construction submitted at the weekly meeting described in Subsection 108.04 of the specifications. TABLE OF CONTENTS INDEX 327 No contract time extension will be granted for placement outside of the beginning and ending dates. Any placem ent deviating from the beginning and ending dates shall be at the sole risk of the contractor.
Asphaltic concrete delivered to the screed unit shall be a free flowing, homogeneous mass in which there is no segregation, crusts, lumps, or migration of the bituminous material. Should any of these conditions be evident in the material delivered to the screed unit, the contractor shall take the necessary corrective action to eliminate such conditions. If any of these conditions persist, the Engineer will order the work to be stopped until satisfactory corrective action has been taken.
If the asphaltic concrete is dumped directly into the paving machine from the hauling trucks, care shall be taken to avoid jarring the machine or moving it out of alignment. No vertical load shall be exerted on the paving machines by the t rucks. Trucks, while dumping, shall be securely attached to the paving machine. If the asphaltic concrete is dumped upon the surface being paved and subsequently loaded into the paving machine, it shall not be dumped at a distance greater than 150 feet in front of the paving machine. The loading equipment shall be self -supporting and shall not exert any vertical load on the paving machine. Substantially all of the asphaltic concrete shall be picked up and loaded into the paving machine.
Self -Propelled Paving Machines: All courses of asphaltic concrete shall be placed and finished by means of self -propelled paving machines except under certain conditions or at certain locations where the Engineer deems the use of self -propelled paving machines impractical. In order to achieve, as far as practical, a continuous operation, the speed of the paving machine shall be coordinated with the production of the plant. Self -propelled paving machines shall spread the mixture within the specified tolerances, without segregation or tearing, true to the line, grade, and crown indicated on the project plans. Pavers shall be equipped with hoppers and augers which will distribute the mixture uniformly in front of adjustable screeds. Screeds shall include any strike- off device operated by tamping or vibrating action which is effective without tearing, shoving , or gouging the mixture and which produces a co urse with a uniform texture and density for the full width being paved. Screeds shall be adjustable as TABLE OF CONTENTS INDEX 328 to height and crown and shall be equipped with a controlled heating device for use when required. Tapered sections not exceeding 8 feet in width, or widened sections not exceeding 4 feet in width may be placed and finished by other means approved by the Engineer.
Except under certain conditions or at certain locations where the Engineer deems the use of automatic controls impractical, asphaltic concrete shall be placed and finished by means of self -propelled paving machines equipped with an automatically actuated control system. The control system shall control the elevation of the screed at each end by controlling t he elevation of one end directly and the other end indirectly, either through controlling the transverse slope or, alternately when directed, by controlling the elevation of each end independently. The control system shall be capable of working with the following devices which shall be furnished with the machine:
throughout its entire length; and
Failure of the control system to function properly shall be cause for the suspension of the asphaltic concrete operations. 407- 7.05 Joints: Longitudinal joints shall be staggered a minimum of 1 foot with relation to the longitudinal joint of the immediate underlying course. The contractor shall schedule its paving operations to minimize exposed longitudinal edges. Unless otherwise approved by the Engineer, the contractor shall limit the placement of asphaltic concrete courses, in advance of adjacent courses, to one shift of asphaltic concrete production. The contractor shall schedule it s paving operations in such a manner to eliminate exposed longitudinal edges over weekends or holidays. Longitudinal joints shall be located within 1 foot of the centerline between two adjacent lanes. TABLE OF CONTENTS INDEX 329 407- 7.06 Compaction:
The temperature of the asphaltic concrete just prior to compaction shall be at least 200 degrees F (250 degrees F when PG TR+ asphalt cement is used).
Compacting and smoothing shall be accomplished by the use of static steel wheel compactors. Vibrator compactors may be used in the static mode only. The compactors shall be self -propelled and shall be operated with the drive wheel in the forward position. A minimum of three compactors shall be provided; however, sufficient compactors shall be provided so that the drums of the compactors when staggered will cover the entire width of the paving machine during initial breakdown. Compactors shall be operated in accordance with the manufacturer's recommendations. Compactors shall be designed and properly maintained so that they are capable of accomplishing the required compaction. Compactors shall weigh not less than 8 tons.
A pass shall be def ined as one movement of a compactor in either direction. Coverage shall be the number of passes as are necessary to cover the entire width being paved. Compaction shall consist of the following rolling sequence: Rolling Sequence Number of Coverages Initial 1 Finish 1 – 2
A sufficient number of compactors shall be used for initial breakdown so that when the compactors are staggered the entire width of the mat being laid is compacted with one forward pass of the compactors. The distance between the paving machine and the initial rolling shall not exceed 200 feet. A separate roller(s) shall be used for final compaction. The roller(s) used for final compaction shall follow as closely behind the initial breakdown rollers as possible. Compaction will be deemed to be acceptable on the condition that the asphaltic concrete is compacted using the type of compactors specified, TABLE OF CONTENTS INDEX 330 ballasted and operated in accordance with the manufacturer's recommendations and with the number of coverages of the compactors as specified. 407- 7.07 Compacting Miscellaneous Items and Surfaces: Asphaltic concrete used in the construction of miscellaneous items and surfaces shall be compacted using compactors, hot -hand tampers, smoothing irons, mechanical vibrating hand tampers, or with other devices to the extent considered necessary by the Engineer. 407- 7.08 Smoothness and Surface Tolerances: Asphaltic concrete shall be compacted as required, smooth and true to the required lines, grades, and dimensions. The Special Provisions may require the smoothness of the final pavement surface to be tested in accordance with Subsection 109.13 of the specifications. Regardless of whether testing in accordance with Subsection 109.13 of the specifications is specified or not, the following requirements shall be met:
shall not vary by more than 1/8 inch from the lower edge of a 10-foot straightedge when it is placed in the longitudinal direction (including across transverse joints), and when it is placed in the transverse direction across longitudinal joints; and
be corrected by the contractor, to the satisfaction of the Engineer. 407- 7.09 Acceptance: Asphaltic concrete will be accepted complete in place if, in the judgment of the Engineer, the asphaltic concrete reasonably conforms to the requirements specified herein. Asphaltic concrete that is not acceptable and is rejected shall be replaced to the satisfaction of the Engineer and at no additional cost to the Department. 407- 8 Method of Measurement : Asphaltic concrete will be measured by the ton for the mixture actually used, which will include the weight of mineral aggregate, bituminous material, and mineral admixture. Measurement will include any weight used in construction of intersections, turnouts, miscellaneous items, or other surfaces. TABLE OF CONTENTS INDEX SECTION 40 8 331 Asphalt cement will be measured by the ton. Mineral admi xture will be measured by the ton for the mineral admixture actually used in accordance with Subsection 403- 2 of the specifications. 407- 9 Basis of Payment: The accepted quantities of asphaltic concrete, measured as provided above, will be paid for at the contract unit price per ton, adjusted if necessary for spread, which price shall be full compensation for the work, complete in place, as specified herein. If the quantity in a spread lot is found to vary by mo re than +5.0 percent from the required quantity, as determined in accordance with Subsection 407- 6.04 of the specifications, no payment will be made for the material which exceeds the +5.0 percent, including asphalt cement and mineral admixture. The Engineer may exclude asphaltic concrete from the spread lot if the Engineer determines that the proposed use of the material or the existing surface conditions are not conducive to the use of spread lots. Payment for asphalt cement will be made by the ton. The results of a nuclear asphalt content gauge shall not be used to determine the weight of asphalt cement as the basis of payment. Adjustments in payment shall be made in accordance with the requirements of Subsection 1005- 3.01 of the specifications . Mineral admixture will be paid for at the predetermined price established in the Bidding Schedule. When required in the Special Provisions, payment for smoothness shall be made in accordance with the requirements of Subsection 109. 13 of the specifications. When lime water is used, no separate payment will be made for the lime water or its application, the cost being considered as included in this contract item. SECTION 408 COLD RECYCLING (BITUMINOUS SURFACE) 408- 1 Description: The work under this section shall consist of furnishing all materials and reclaiming (milling) a portion of the existing asphaltic concrete pavement, or utilizing stockpiled reclaimed asphalt pavement, sizing the material, and mixing the material with an e ngineered emulsion, water, and other additives as necessary and as required by the mix design, to produce a homogeneous recycled asphalt mixture which is placed and TABLE OF CONTENTS INDEX 332 compacted on the roadway. The work shall conform to the requirements of the project plans, and the specifications, and be accomplished by means of either in- place recycling or central plant recycling, or a combination of the two. 408- 2 Cold Recycle Material: Cold recycled material shall consist of a homogeneous blend of reclaimed asphalt pavement, corrective aggregate, engineered emulsion, water, mineral admixture, and other additives as required by the mix design. Cold in -place recycled material shall consist of existing asphalt pavement that is reclaimed and processed in place. Cold cent ral plant recycled material shall consist of stockpiled reclaimed asphalt pavement that is processed offsite at a central plant. Material that is not transported to a cold central recycling plant but is milled and placed in a windrow adjacent to the original location and subsequently screened, crushed, and mixed with an engineered emulsion and other additives prior to placement and compaction on the roadway is also identified as cold in- place recycled material under this specification. The unit weight, engi neered emulsion percentage and mineral admixture percentage shall be as specified in the Special Provisions. 408- 2.01 Reclaimed Asphalt Pavement (RAP): The Reclaimed Asphalt Pavement, hereinafter referred to as RAP, shall consist of asphaltic concrete removed from the project roadway or previously stockpiled salvaged asphaltic concrete. RAP shall not contain injurious material, clay balls, adhering films, pavement markers, loop detector wires, paving fabrics, vegetable matter, or excessive amounts of crack fill material, and/or cutback asphalt. RAP stockpiles shall be processed to be homogeneous and shall not include materials not accounted for in the mix design. Residual materials that cannot be sufficiently removed from the RAP may be included in the cold recycled material provided the contractor can demonstrate that incorporation of the residual materials will not adversely affect performance if dispersed evenly throughout the RAP and accounted for in the mix design. RAP stockpiled for purposes of coldce ntral plant recycling may be kept in a single stockpile, but shall be fractionated into two or more sizes if gradation consistency cannot be maintained during production. The lower 12 inches of stockpiled RAP shall not be incorporated into the cold recycled material. Cold central plant composite RAP production tolerances for percent passing the required sieves are provided in Table 408- 1. TABLE OF CONTENTS INDEX 333 TABLE 408 -1 COMPOSITE RAP GRADATION PRODUCTION TOLERANCES Sieve Size 1 Inch Max. Aggregate 1-1/4 Inch Max. Aggregate 3/4” ±10% ±15% 1/4” ±10% ±10% No. 4 ±8% ±8% No. 40 ±4% ±4% RAP shall be reduced to 100- percent passing the sieve size specified in the Special Provisions prior to mixing in a traveling or central plant. The Engineer will take verification samples of processed composite RAP material prior to its introduction into the cold central plant recycling process. 408- 2.02 Recycling Additive: Recycling additive shall include a mineral admixture of lime slurry and may include an additional mineral admi xture of Portland cement and/or corrective aggregate to meet performance requirements or improve cold recycled material mix cohesion, aid in curing or early strength for opening to traffic, or provide resistance to moisture induced damage. The usage rate of all additives shall be determined by the mix design.
Corrective aggregate shall consist of either crushed virgin aggregate or fractionated existing RAP added to the RAP material to correct deficiencies in aggregate structure, stability, and/or performance criteria. Crushed virgin aggregate used as corrective aggregate shall meet the requirements of Subsection 416- 3.01 of the specifications. The quantity of corrective aggregate shall be determined by the mix design.
Quicklime or hydrated lime shall meet the requirements of AASHTO M 216 or ASTM C977 and the quantity of lime included in the cold recycled material shall be determined by the mix design. The slurry shall have no less than 30 percent solids.
Portland cement may be added in dry or slurry form to the cold recycled mixture. If added in slurry form, the slurry shall contain no less than 30 percent solids. Portland cement shall be Type I or II conforming to AASHTO M 85/ASTM C15 0 or AASHTO M 240/ASTM C595. The quantity of cement included in the cold recycled material shall be determined by the mix design. TABLE OF CONTENTS INDEX 334 408- 2.03 Engineered Emulsion for Cold Recycling: The emulsion used for cold recycling shall be a bituminous, solventless, engineered, emulsified asphalt conforming to Section 1005 and Table 408- 2 of the specifications. The emulsion shall have been used successfully on at least two cold recycled projects in the Western United States. A successful project is one with at least 10 l ane miles of cold recycling processing, a minimum 10- year traffic loading of 300k ESALs, and the surface opened to traffic no later than the morning after processing without the development of rutting or raveling to the extent that a detour in traffic or r epair was required. Any failure is cause to deny approval. The performance grade of the residual asphalt binder for this project shall be grade specified in the Special Provisions. TABLE 408 -2 ENGINEERED EMULSION FOR COLD RECYCLING Test On Emulsion (1) Test Method Requirement Settlement: 5 days, % maximum (2) AASHTO T 59 5 Sieve: Retained on No. 20, % maximum AASHTO T 59 (3) 0.30 Particle Charge (4) AASHTO T 59 Pass or Fail (5) Residue from Distillation: % minimum AASHTO T 59 (6) 63 Oil Distillate, Volume of Emulsion, % maximum AASHTO T 59 (6) 1.0 Tests on Residue from Distillation: Dynamic Shear of Original Binder: G*/Sin δ, kPa, minimum AASHTO T 315 1.00 Creep Stiffness of PAV Binder: S, MPa, maximum AASHTO T 313 (7) 300 m-value at 60 sec., minimum AASHTO T 313 (7) 0.300 Notes:
five days of production.
TABLE OF CONTENTS INDEX 335 TABLE 408 -2 ENGINEERED EMULSION FOR COLD RECYCLING
a maximum pH value of 6.7 will be acceptable.
without polymer. The AASHTO T 59 alternative requirements are used for emulsions with polymer. Maximum distillation temperature for polymer modified emulsions shall be 350 F.
RTFO aging, the residue still lacks the stiffness necessary to complete testing at the appropriate test temperature from Table 1 of AASHTO M 320, the test temperature may be lowered in order to complete testing and the lower test temp erature shall be reported on the mix design.
A Certificate of Compliance conforming to the requirements of Subsection 106.05 of the specifications shall be submitted for the engineered emulsion. 408- 2.04 Water : Water required for lime or cement slurry and to facilitate milling, mixing, coating, and compaction shall meet the requirements of Subsection 1006- 2.02 of the specifications. The total amount of water to be added, adjusted for moisture in the existing pavement during production, shall be determined by the mix design. 408- 2.05 Fog Coat: The fog coat shall consist of the engineered emulsion, or a CRS emulsion compatible with the engineered emulsion used during recycling, meeting the requirements of Section 1005 of the specifications. Fog coat may be diluted up to 60 percent by volume with water. 408- 3 Mix Designs: The mix design(s) for cold recycled material shall be developed in a laboratory under the direction of a Professional Engineer experienced in such mix designs. A discussion of the characteristics of the in- place material to be recycled that includes the in- situ density and moisture content shall be discussed in the mix design. Any existing material that will not be incorporated into the cold recycled material, as determined by the contractor, such as recent chip seals, cold mix patches or overlays, and crack fill material shall not be included in the material for the mix design. A list or table of areas of the existing road or portions of the existing stockpiled material requested to be excluded from cold recycling that are in addition to any such areas TABLE OF CONTENTS INDEX 336 identified in the plans shall be submitted to the Engineer. The Engineer will determine which, if any, of the requested areas of the roadway or portions of the existing stockpiles are to be excluded. The mix design shall be developed in accordance with the Asphalt Recycling & Reclaiming Association’s “Recommended Mix Design Guidelines for Cold Recycling Using Emulsified Asphalt Recycling Agent (CR201)” and on the basis of the followi ng criteria and tested in accordance with the requirements of the associated test methods provided below in Table 408- 3. TABLE 408 -3 COLD RECYCLING MIX DESIGN CRITERIA Criteria Requirements Test Method Engineered Emulsion Content, %, by dry weight of RAP and corrective aggregate Report Only RAP Binder Content, % by dry weight of RAP Report Only ASTM D2172/ AASHTO T 164 Moisture Content, % by dry weight of RAP and corrective aggregate 1.5 to 3.0 AASHTO T 255 Lime, % dry additive by weight of dry RAP and corrective aggregate 0.5 to 1.5 Portland cement, % dry additive by weight of dry RAP and corrective agg. (if used) Report Only Dry Screened RAP Gradation Maximum Top Size and Medium and Coarse Gradation (per Subsection 408-3.01) AASHTO T 11/ T 27 Corrective Aggregate, %, by weight of dry RAP (if used) Report Only Corrective Aggregate Gradation Report Only Arizona Test Method 201 Combined Gradation w/ & w/o admix Report Only Arizona Test Method 201 Engineered emulsion film thickness, micron Report Only Asphalt Institute Manual MS-2 RAP Binder PG Report Only AASHTO M 320 TABLE OF CONTENTS INDEX 337 TABLE 408 -3 COLD RECYCLING MIX DESIGN CRITERIA Criteria Requirements Test Method Bulk Specific Gravity of Gyratory Specimens (30 gyrations) Report Only AASHTO T 166 Maximum Theoretical Specific Gravity Report Only AASHTO T 209 Air Voids of Compacted, Cured Specimens 8.0-15.0% AASHTO T 269 Indirect Tensile Strength: psi, minimum (1) 45 AASHTO T 283 Tensile Strength Ratio: min.% (1) 60 AASHTO T 283 Raveling Test: % wear loss, maximum 7.0 ASTM D7196 RAP Coating Test: minimum Good AASHTO T 59, Hamburg Wheel Tracker (2) 12.5 mm maximum at 5,000 passes AASHTO T 324 Notes:
design air void target.
48 hours at 60 degrees C and tested at 50 degrees C for locations above 3, 000 feet in elevation and tested at 56 degrees C for locations below 3 ,000 feet in elevation.
If ambient conditions are expected to exceed 85 degrees F during construction, high temperature validation of the mix design, as described in ARRA CR201, Chapter 4, shall be performed. High calcium quicklime or hydrated lime shall be added to the cold recycled material in slurry form, at a rate of 0.5 to 1.5 percent by weight of dry rap and corrective aggregate. If dry cement is included to meet performance requirements, the ratio of residual asphalt in the engineered emulsion to the weight of dry cement shall be at least 3.0 :1.0. The cement shall be within the range of 0.0 to 1.0 percent by dry weight of RAP and corrective aggregate. 408- 3.01 Mix Design for Cold In -Place Recycled Material: A mix design, or mix designs, shall be developed by the contractor for each unique segment of roadway to be recycled, as identified on the plans. Cores shall be taken at a minimum frequency of 2,500 foot intervals and where a significant change in material exists, either TABLE OF CONTENTS INDEX 338 visually or through examination and analysis of the cores. Additional cores shall be taken to locate the transition to within 500 feet or less. A list or table of areas requested to be excluded from cold in- place recycled construction that are in addition to any such areas identified in the plans, shall be submitted to the Engineer. The Engineer will determine which, if any of the requested areas, are to be excluded. Representative material of at least 350 pounds shall be obtained from each unique segment from within the wi dths and depths to be recycled either by taking additional cores or by milling. Material obtained shall be consistent with the intended paving plan so that mix designs are developed for the cold in- place recycling operations performed within each segment. Locations for coring/milling shall be determined by the contractor and will be approved by the Engineer. The maximum distance from beginning or end of the segment and sample locations, and spacing between subsequent sample locations shall be no more than 2,500 feet. If stripping is observed within any core, the Engineer shall be notified and allowed to observe the core and determine any additional coring necessary. If coring, three cores shall be obtained from each location with approximately 15 percent of the cores taken from the shoulder (if the shoulder is included in the cold in- place recycling) and 25 percent from within 3 feet of the centerline. The remaining cores shall be split approximately evenly between vehicle wheel tracking paths and outsid e wheel tracking paths. If milling, material shall be representative of the widths to be recycled. Cores shall have a minimum diameter of 6 inches. The approximate location of transitions and average unit weight of cores representative of each unique segment shall be reported on the associated mix designs. Core holes shall be patched with a material approved by the Engineer. A core and/or milling log including the date, station, milepost, offset, core thickness/mill depth, and mill width shall be provided to the mix design laboratory and be attached to the mix design. Any existing material that will not be included in cold recycling shall be trimmed from cores and discarded. Each core / sample of millings shall be identified to correspond with the log. The material from each segment for which a mix design will be prepared shall be broken down with a laboratory milling machine or mechanical crusher and combined into a homogenous mixture representative of the segment. Both a medium and a coarse band mix design meeting the associated gradation band shown in the table below shall be developed with engineered emulsion for the material obtained from each unique segment of roadway. Artificial laboratory grading consisting of sieving and re- compositing RAP material may be required to achieve the indicated gradations. TABLE OF CONTENTS INDEX 339 Sieve Size Medium Gradation (% Pass) Coarse Gradation (% Pass) 1-1/4 Inches 100 100 3/4 Inches 93-97 83-87 # 4 48-52 38-42 # 30 8-12 3-7 # 200 1.0-3.0 0.5-2.0
408- 3.02 Mix Design for Cold Central Plant Recycled Material: For existing reclaimed asphalt pavement (RAP) already stockpiled, or RAP that will be reclaimed from within the existing project roadway, transported, and processed off site by cold central plant recycling, the mix design(s) shall be developed for the expected gradation during production. This determination shall be made by operating the plant in a manner consistent with that which will occur during production. The mix design for cold central plant recycled material shall meet the requirements of Table 408- 3 in Subsection 408- 3.01 of the specifications. The source of any existing RAP, including location, depth, and original mix design information, if known, shall be provided to the Engineer. A new mix design shall be developed whenever there is a significant change in the source or properties of RAP, as determined by the Engineer. 408- 4 Equipment: The recycling equipment shall be capable of milling the existing roadway (for cold in- place recycling), sizing the milled and/or stockpiled RAP, and mixing the RAP with the engineered emulsion and any additives required by the mix design in a controlled process that produces a homogeneous and consistent cold recycled mixture meeting the requirements herein. The equipment shal l be capable of removing/placing the material to the lines and grades shown on the plans. 408- 4.01 Cold In -Place Recycling Train Requirements: Cold in -place recycling trains shall be self -propelled multi -unit trains designed specifically for cold in- place pavement recycling with automatic grade control and be equipped with a planing unit, screening and crushing unit, and a dedicated mixing chamber. Cold in- place recycling trains shall be equipped with the necessary equipment to satisfactorily perform the work. The equipment shall be controlled electronically by a computerized central control unit receiving inputs from belt scales and flow meters to control the addition of the engineered emulsion, recycling additives, and water. TABLE OF CONTENTS INDEX 340
The primary milling equipment/cold planer shall have a minimum cutter width of 12.5 feet and be equipped with depth controls capable of maintaining the desired cutting depth to within 1/4 inch, and shall have effective means for control ling cross- slope. The milling equipment shall not disturb underlying material. Use of a heating device to soften the existing pavement will not be permitted. If corrective aggregate is required by the mix design, the primary cold planer shall be capable of capturing all corrective aggregate placed in a windrow ahead of the cold planer. The cold planer shall include extensions if road geometry and the approved cold in- place recycled material paving plan require such or a supplemental mill shall be used ahead of the primary cold planer. The operating mode of the primary cold planer shall be set to a down cutting mode unless a more desirable gradation is obtained by operation in an up cutting mode. The addition of lime or cement slurry additive shall occur at the cutter head and be computer controlled and capable of automatic adjustments for working speed. The application system shall apply the slurry at a minimum tolerance of 0.1 percent of the required rate. The screening/crushing unit shall adequately screen RAP exceeding the maximum size, crush oversized RAP, and reintroduced crushed RAP to the screen prior to mixing with the engineered emulsion. The screen must remain clear of buildup of unsuitable material such as crack fill or binder ric h patch materials that might otherwise clog the screen. A conveyor belt shall transfer the screened and crushed RAP and any recycling additive to the mixing chamber/pugmill where the combination of materials shall be thoroughly mixed with the engineered em ulsion and additional mixing water. A calibrated belt scale/weigh bridge shall be located on the conveyor belt immediately prior to the mixing chamber. An electronically controlled, computerized metering , and proportioning system shall monitor the weight of processed RAP (and additive) and control the addition of engineered emulsion. An independent source equipped with a flow meter shall be used to spray additional mixing water to disperse the engineered emulsion. The metering system shall be equipped wi th alarms should any part of the operation fall outside of tolerance. The system shall be capable of making automatic adjustments for fluctuations in the weight of processed RAP and additive entering the mixing chamber and controlling the addition of engi neered emulsion to within 0.1 percent of the required rates. The rate of addition of mixing water shall be adjustable to compensate for fluctuations in existing pavement moisture or as the contractor determines necessary for production. Excessive additional mixing water will not be permitted. If at any time the ability of the equipment or metering system to accurately monitor and control the production process is in question, the Engineer may halt further in- place operations until such time that the TABLE OF CONTENTS INDEX 341 contr actor has demonstrated that the equipment and metering system is functioning properly and producing acceptable material.
Prior to use on the project, the cold in- place recycling train shall be calibrated, or evidence of calibration within the previous 12 months shall be provided to the Engineer for review. The calibration shall include the items listed below. Any changes in recycling equipment will require re- calibration. If calibration is necessary, the contr actor shall provide certified platform scales at the calibration site. A copy of the certification shall be provided to the Engineer prior to calibration. The Engineer will observe the calibration and will approve if the calibration standards are met. T he contractor shall record the results of the calibration and provide it to the Engineer prior to beginning recycling operations. Aggregate Weigh Belt Scale:
belt scale;
sensor ;
percent of calibration) ;
belt length and belt speed;
each run are both within 1 .0 percent of each other and within 1.0 percent of the actual weight as weighed on the certified platform scales; and
hour and total tons of material processed. TABLE OF CONTENTS INDEX 342 Engineered Emulsion Metering Device:
other), size (pipe diameter), and serial number of the emulsion meter ;
per minute for analog) ;
mixer through a calibrated metering device at two different speeds;
each run are both within 1 .0 percent of each other and within 1.0 percent of the actual weight as weighed on the certified platform scales; and
varying the engineered emulsion delivery rate. Slurry Metering Device:
other), size (pipe diameter) ;
per minute for analog) ;
using a mass- flow coriolis effect type meter at two different speeds;
means of varying the slurry delivery rate; and
each run are both within 1 .0 percent of each other and within 5.0 percent of the actual weight as weighed on the certified platform scales. The cold in- place recycling train shall be calibrated to the satisfaction of the Engineer. A known amount of aggregate shall be processed through the cold in- place recycling train. The cold in- place recycling train shall be fully operational and shall process the aggregate with any required engineered emulsion, recycling additive, and additional mixing water. The contractor shall provide a computer printout of the materials metered and controlled during the calibration process. The quantities on TABLE OF CONTENTS INDEX 343 the printout will be compared to the actual quantity of materials used to determine the accuracy of the metering system. The contractor shall demonstrate during the calibration that all components of the cold- recycling train are functioning properly. If reason exists to question the functionality, the Engineer may prevent in place operations until such time that the contractor has corrected any deficiencies and demonstrated an acceptable calibration. After placing the first 1, 000 feet of cold recycled material at the project site, the contractor shall stop production and verify that the quantities are within the target tolerances before placing additional cold recycled material. Verification shall include tank level measurements and gauge to meter comparisons. During operation, from 5 to 75 tons, the Department will verify that the digital display of the electronically controlled computer monitoring and proportioning system indicates that the required additions of all materials are as desired and maintained at acceptable tolerances. 408- 4.02 Cold Central Plant Recycling Requirements: Cold central plant recycling shall consist of using a stationary cold mix plant to produce cold recycled material. The plant shall have a screening/crushing unit, the appropriate number of cold feed bins for corrective aggregate and fractionated RAP, conveyor belts with calibrated belt scales, an electronically controlled, computerized liquid additive system, a pugmill or drum mixer, and surge bins, storage silos, or the ability to store cold recycled material in stockpiles or discharge directly into haul vehicles. If no corrective aggregate or RAP fractionation is required, the plant may have a single cold feed bin/hopper. Except for drying, heating, and temperature monitoring requirements, the plant shall meet the requirements of Section 403 of the specifications.
The screening/crushing unit shall adequately screen RAP exceeding the maximum size. Excessively large RAP may be scalped and completely removed from the RAP material, or may be crushed and reintroduced to the screen. A separate cold feed bin shall exist for each size of corrective aggregate and fractionated RA P as required by the mix design or to control gradation. If necessary, dividers shall exist to ensure that no RAP or corrective aggregate from a single bin spills over into an adjacent bin. The plant shall transfer corrective aggregate and RAP to the pugm ill or mixing drum with conveyor belts equipped with calibrated belt scales. TABLE OF CONTENTS INDEX 344 The belt scales shall be linked to an electronically controlled, computerized liquid additive system that accurately meters the materials into the mixer based on the weight of the RAP. Liquids (emulsion, water, and additives in slurry form) shall be metered into the mixer using positive displacement pumps with interlocks to shut off the supply when the chamber is empty. Storage of cold recycled material produced shall be such that the material is protected and does not become contaminated.
Prior to use on the project, the cold central plant shall be calibrated, or evidence of calibration within the previous 12 months shall be provided to the Engineer for review. The calibration shall include the items listed below. Any changes in recycling equipment will require re- calibration. If calibration is necessary, the contractor shall provide certified platform scales at the calibration site. A copy of the certification shall be provided to the Engineer prior to calibration. The Engineer will observe the calibration and will approve if the calibration standards are met. The contract or shall record the results of the calibration and provide it to the Engineer prior to beginning recycling operations. Aggregate Weigh Belt :
speed;
console indicators are within 1 percent of the actual mass as weighed on the certified platform scales; and
material and the total tons of material processed. Engineered Emulsion Metering Device:
calibrated metering device;
delivery rate; and
design so the masses or gallons shown on the indicators are TABLE OF CONTENTS INDEX 345 within 0.5 percent of the actual mass as weighed on the certified platform scales. Slurry Metering Device:
Coriolis effect type meter ;
slurry delivery rate; and
approved mix design so the masses or gallons shown on the indicators are within 1 percent of the actual mass as weighed on the certified platform scales. 408- 4.03 Haul Trucks: Haul trucks for cold central plant recycled material shall have smooth, clean beds. Any asphalt release agents used shall be approved by the Engineer. Diesel fuel shall not be used as a release agent. A sufficient number of haul trucks shall be provided to ensure delivery to the cold recycling operation within sufficient time to allow continuous and proper placement and compaction of the cold recycled material. 408- 4.04 Mechanical Spreader: If, in the judgement of the Engineer, a uniform windrow of corrective aggregate cannot be placed with haul trucks, a mechanical spreader shall be used to place corrective aggregate on the existing pavement surface in a uniform and controlled amount ahead of the cold in- place recycling train. Alternati vely, a conventional paver may be used. 408- 4.05 Slurry Mixing and Storage Tanks: Lime or Portland cement slurry mixing and storage tanks shall be adequately sized to provide sufficient supply for the rate of cold recycled material production. Tanks shall have agitators for mixing and continued agitation during storage to keep solids in suspension. 408- 4.06 Material Transfer Vehicle/Windrow Elevator: The equipment used to transfer materials from the grade to the paver shall be capable of transferring all material from the grade to the paver hopper. The equipment used to transfer materials shall allow the paver to operate continuously, keeping the head of material in front of the screed constant by supplying a continuous amount of mix to the screed. TABLE OF CONTENTS INDEX 346 408- 4.07 Paver Requirements: Pavers may be either cold mix pavers or conventional asphalt pavers (operated without screed heating) capable of adjusting the placed thickness and width of cold recycled material. Pavers for placement of cold recycled material may be either attached to the cold in- place recycling train or detached. Screed augers shall be of sufficient size to fully fill the screed and screed extensions without causing segregation within the cold recycled material. The paver hoppers shall be appropriately sized to accommodate changes in pavement section, thickness, and/or width. 408- 4.08 Compaction Roller Requirements: Both double steel drum vibratory and large sized pneumatic- tired rollers shall be used for compaction of cold recycled material. Double drum vibratory rollers shall weigh at least 10 tons; pneumatic rollers shall weigh at least 25 tons. The contractor shall have a certified weight ticket available for verification of actual weight upon request by the Engineer. The tire pressure of pneumatic- tired rollers shall be 90 ± 5 pounds per square inch unless otherwise specified by the manufacturer. A sufficient number of pneumatic- tired rollers and double drum vibratory rollers shall be utilized to adequately compact the cold recycled material based on the rate of cold recycling production and paving speed. Rollers shall be at least 5.5 feet in width or sized to prevent uneven overlap of subsequent passes and have properly functioning water spray systems to prevent pickup. Additional smaller size rollers may be utilized if approved by the Engineer. 408- 4.09 Water Truck: A water truck shall be used to supply water to the milling equipment during cold in- place recycling operations. The water truck system shall be capable of supplying the mixing chamber with an independent source of water meeting the requirements of Subsection 408 -2.04 of the specifications. 408- 4.10 Fog Sealing and Blotter Sand Spreading Equipment: A certified distributor truck capable of spreading emul sified asphalt at a uniform rate over the full width of the traffic lane in a single application shall be utilized for fog sealing. No traffic will be allowed on surfaces receiving a fog seal until the emulsion has broken and cured sufficiently. Blotter sand meeting the requirements of Section 404 of the specifications shall be applied, if necessary. TABLE OF CONTENTS INDEX 347 408- 5 Just -in-Time Training: At least 10 working days prior to cold recycling operations, the contractor shall provide Just -in-Time Training for cold recycli ng construction and related operations to contractor and Department personnel. The training shall be presented by a firm or an individual experienced in cold recycling acceptable to the Engineer. The training shall cover the following topics:
(if utilized) ;
& Mixing ;
TABLE OF CONTENTS INDEX 348
Design Transitions;
408- 6 Pre-Cold Recycling Meeting: At least one week prior to cold recycling operations, the contractor shall conduct a pre- cold recycling meeting with all contractor and Department personnel involved in the cold recycling process to discuss the requirements herein and the following:
recycling process;
TABLE OF CONTENTS INDEX 349
pertinent to the cold recycling operation. 408- 6.01 Cold Recycling Operations Plan: An illustrated cold recycling operations plan shall be submitted to the Engineer which indicates:
necessary;
incorporated into the cold recycled material ;
Any updates shall be submitted to the Engineer at each weekly meeting. 408- 6.02 Cold Recycling Quality Control Submittal: A cold recycling quality control submittal shall be provided to the Engineer which identifies:
qualifications, and/or certifications. Personnel experience pertaining to cold recycling shall also be included; and
additive or additional mixing water, or transition to a different mix design will be determined. Specific quality control requirements are provided in Subsection 408- 9 of the specifications. 408- 7 Construction Requirements: Cold recycling construction shall be performed in accordance with the requirements herein. Throughout the cold recycling operation, adjustments may be made to the process including rates at which the engineered emulsion, recycling additives, and water are incorporated into the cold recycled material. However, such changes shall be made TABLE OF CONTENTS INDEX 350 judiciously and only by experienced personnel based on substantive information verified by quality control, or pre- construction investigation. All changes and adjustments shall be reported to the Engineer. At the conclusion of each day’s operations, and prior to subsequent processing or placement of cold recycled material, a Daily Production Report which provides the quantities of all materials used and associated rates shall be provided to the Engineer. 408- 7.01 Pre-Construction Investigation: In addition to coring and milling performed for the mix design, the contractor may take additional cores or perform additional milling to aid in making adjustments to the cold recycling process during construction. Any such work shall include proper traffic control, safety precautions, and patching the pavement where material is removed. The contractor shall request such investigation and include details of where and how material will be obtained and patched. The request shall be submitted to the Engineer for approval. 408- 7.02 Road Preparation: Prior to cold recycling operations, the contractor shall (1) identify and repair areas of insufficient support including subgrade and base course, as approved by the Engineer; (2) perform necessary valve and manhole cover/collar and utility installation adjustments; (3) mark areas containing objectionable material and excessive crack filling material to be excluded from the RAP, (4) locate utilities and mark other areas that must be avoided, (5) perform any required pre- milling for grade control, cross slope, or profile corrections, and removal of unsuitable materials, (6) identify by station the boundaries of materials which require different mix designs, adjustments to emulsion content, or corrective aggregate, and (7) clean all dirt, mud, vegetation, standing water, combustible materials, oils, raised or recessed pavement markers, and any other objectionable material from the roadway by means of sweeping, vacuuming, blading, or other acceptable means. This includes excess water accumulating on the surface or in the milled trench due to over application or leaking equipment. These activities ma y be conducted concurrently with the cold recycling operation provided they do not interfere with cold recycling operations. If in the opinion of the Engineer, such work will be in conflict with or negatively affect or be affected by the cold recycling operation, the Engineer may stop cold recycling operations until conflicts and/or negative impacts can be avoided. 408- 7.03 Application of Recycling Additive: Lime, and, when required, corrective aggregate and/or Portland cement shall be introduced at the rates and amounts required by the mix design and in accordance with the requirements herein. TABLE OF CONTENTS INDEX 351
For cold in- place recycling, imported fractionated RAP or virgin crushed aggregate shall be spread in a uniform and consistent manner (windrow or ribbon) ahead of the cold planer using belly dumps, a mechanical spreader, or a conventional paver. A blade shall be used, if necessary, to correct deficiencies, excesses, or inconsistencies in placement. The area over which each load of known weight of corrective aggregate is placed shall be determined and the application rate calculated, estimated by unit weight of existing pavement. The application rate shall be within 5 percent of the rate required by the mix design. Whe n a conventional paver is used for placement of corrective aggregate delivered by belly dumps, a pickup vehicle as described in Subsection 4.06 of the specifications capable of capturing all of the corrective aggregate shall be used to transfer the corrective aggregate to the paver hopper. For cold central plant recycling, corrective aggregate shall be introduced from a cold feed bin calibrated for the correct application rate.
Portland cement placed as a dry additive for cold in- place recycling shall be placed on the existing asphalt pavement surface ahead of the milling operation. The cement shall be placed in a windrow and the distribution controlled volumetrically with a known weight of material in each load. The application rate shall be verified using a drop pan or canvas patch of known dimension, and the material captured weighed. Application rates shall be within 0.1 percent of the rate required by the mix design, as measured by this method. Dust control measures for Portland cement placed on the existing pavement, whether necessary due to wind or adjacent traffic, may include limiting the distance between the spreader and cold in- place recycling train, pre- wetting the road surface, or other means acceptable to the Engineer. If dust cannot be controlled, any required mineral admixture shall be added in slurry form or operations shall be suspended until conditions improve. No traffic or construction equipment shall pass over spread additive. For cold central plant recycling, dry cement or lime shall be added to the pugmill via silo auger or separate device with a calibrated belt scale. If a drum mixer is used, the additives shall be combined with the RAP/corrective aggregate using a pugmill mixer prior to the dr um. Sufficient moisture shall be present in the RAP/corrective aggregate to prevent loss of additive during mixing. For cold in -place recycling or mixing with a cold mix plant, the addition of lime or Portland cement shall be metered by the electronically TABLE OF CONTENTS INDEX 352 controlled, computerized system such that the weight of additive as a percent of the weight of RAP and corrective aggregate is controlled to within 0.1 percent of the target rate and displayed digitally.
Recycling additive added as sl urry may be produced either by portable batching equipment or processed inline and fed directly to the cold in- place recycling mixing chamber. Slurry may be added directly to the mixing chamber in both cold in- place recycling and cold central plant recycling, or sprayed over the cutting teeth of the cold planer in cold in - place recycling. Slurry shall be produced at the jobsite or central plant with control of the solids and liquids proportioning. The application of slurry shall be controlled by mass or volume meters to ensure correct application rates. The consumption of cement or lime and water shall be obtained from the computer that controls the slurry mixing unit. For cold in- place recycling, a volumetric distribution check shall be performed to en sure that the area cold recycled for each batch of slurry contains the amount of recycling additive required by the mix design and also to verify that control exists for application of the slurry. Slurry shall be applied such that the rate of additive is within 0.2 percent of the rate required by the mix design. For lime slurry, chemical or quick lime shall be reacted with water to form hydrated lime slurry. The amount of lime and water added to each batch shall be known. When necessary, the slurry shall be allowed to cool sufficiently prior to addition to the cold recycled material to prevent adversely affecting the break time of the emulsion. Slurry shall be kept in suspension during storage and transport with agitators or similar equipment. 408- 7.04 Addition of Engineered Emulsion: The engineered emulsion shall be of proper temperature and viscosity prior to injecting into the mixing chamber. The addition of the engineered emulsion shall be metered by the weight of the RAP and corrective aggregate with a calibrated meter capable of metering the amount of engineered emulsion to within 0.1 percent of the target rate. The metering device shall be capable of automatically adjusting the flow of the engineered emulsion to compensate for any variation in the weight of RAP and corrective aggregate introduced into the mixing apparatus. 408- 7.05 Addition of Water: For cold in- place recycling, additional water for dispersion of the engineered emulsion and compaction may be added either at the cutting head of the cold planer or in the mixing chamber. If modification to the application rate of the engineered emulsion occurs, the addition of water shall be adjusted accordingly to ensure that the total fluids injected remains consistent with the mix design. For water added in the mixing TABLE OF CONTENTS INDEX 353 chamber, the mixing apparatus shall have an independent source of water to adequately disperse the engineered emulsion and/or introduce water to aid in compaction, also metered to within 0.1 percent of the target rate. 408- 7.06 Metering and Proportioning: The electronically controlled, computerized monitoring system shall display digital readings for the combined processing rate of RAP and corrective aggregate, addition rates for engineered emulsion, recycling additive, and water, the controls for which, shall be used to make adjustments during production. The system controlling the addition of engineered emulsion and additional mixing water shall be based entirely on the weight of RAP and corrective aggregate and any offsets entered for existing moisture in the pavement/RAP. The system controlling the addition of slurry for cold in- place recycling shall be based on the widths and depths being recycled, unit weight of the pavement, weight of corrective aggregate, and forward speed of the cold in- place recycling train. 408- 7.07 Processing and Placement: The RAP shall be crushed and sized to the maximum particle size or fractionated and blended with the required amount of recycling additives, engineered emulsion, and water to facilitate both adequate dispersion of the engineered emulsion and compaction, to produce cold recycled material consistent with and meeting the requirements of the mix design. The mixture produced shall be a homogeneous recycled mixture and shall exit from the mi xing chamber in a manner that prevents particle segregation. During cold recycling operations, the equipment shall be operating as intended; any alarms or displays that indicate production is not occurring in accordance with the production targets will result in an immediate stop to production until the contractor has made necessary corrections/repairs. Raised or recessed pavement markers, loop detector wires, excessive amounts of rubberized crack fill and other materials not intended for inclusion in the cold recycling material should be removed from the roadway and/or RAP stockpiles either prior to cold recycling operations or as observed during the recycling or fractionating process. Any residual materials included in the cold recycled mixture shall be appropriately sized and blended, as allowed by the mix design, to not adversely affect the appearance or performance of the recycled pavement. The recycled mixture shall be spread using a screed to the design widths and elevations/thicknesses without the occurrence of segregation, tearing, or scarring, and handwork shall be minimized. TABLE OF CONTENTS INDEX 354 At no time shall processed or delivered recycled material placed on grade extend a distance ahead of the paver such that the emulsion begins to break prior to placement with the paver screed. Any deleterious material in the paved cold recycled material shall be removed and the area repaired with additional cold recycled material. If during production the contractor desires to adjust the engineered emulsion target by more than 0.3 percent, or the corrective aggregate target by more than 10 percent, in order to produce acceptable cold recycled material, the contractor shall notify the Engineer and obtain representative samples from production at the adjusted rate(s). Laboratory testing shall be performed by the contractor to verify that the adjusted targets result in cold recycled material satisfying the criteria in Table 408- 3. If test results are not satisfactory, a new mix design shall be prepared to determine the appropriate targets for the prevailing material. Any placed material deemed by the Engineer to be inadequate shall be re -recycled at the discretion of the Engineer.
For cold in- place recycling, the existing asphalt pavement, except for areas designated for exclusion, shall be cold milled to the length, depth, and width shown on the plans. There shall be no gaps of unrecycled pavement between successive/adjacent cuts with the cold planer. Longitudinal joints between successive/adjacent cuts shall overlap a minimum of 3 inches and not exceed 6 inches. Transverse joints shall overlap a minimum of 2 feet and not exceed 4 feet. When corrective aggregate is utilized, such material shall be placed uniformly on the existing road surface ahead of the cold recycling train. When paving fabric or other geosynthetics are encountered during the cold milling operation, the necessary changes in equipment or operations shall be made to either incorporate adequately shredded material into the cold recycled material, if allowed by the mix design, or completely remove such material. If allowed, any oversize pieces shall be removed. If during production the contractor identifies material, not previously identified, which should be discarded, the contractor shall provide the extent of such material to the Engineer. If in the opinion of the Engineer the material should be removed, such areas shall receive material meeting the requirements of Section 409, 416, or 417 of the specifications, as determined by the Engineer, paid for at the applicable bid item price. Any fillet of fine aggregate material, which forms adjacent to a vertical face, shall either be r emoved from the trench prior to the spreading of the bituminous mixture, or dispersed to the center of the trench to the satisfaction of the Engineer. The dispersing of the fine aggregate material shall be accomplished with a power broom attached to the milling machine prior to the introduction of the bituminous mixture onto the roadway. TABLE OF CONTENTS INDEX 355
For cold central plant recycling, the RAP shall be fractionated into a sufficient number of stockpiles to facilitate production of a consist ent mixture when blended with recycling additives, engineered emulsion, and water, as required by the mix design. The bottom 12 inches of material in each RAP stockpile shall not be incorporated into the cold recycled material and tracking over RAP with loading equipment shall be minimized. RAP stockpiles shall be protected from contamination and RAP shall be placed into cold feed bins such that spillage into adjacent bins does not occur. Dispensing of cold recycling material into haul vehicles, transporti ng the material to the project, placement of the material on grade or in the paver hopper, and paving operations shall be such that segregation within the cold recycled material does not occur. 408- 7.08 Compaction The time at which compaction may begin after the recycled material has been placed is dependent on the engineered emulsion used, recycling additives, and ambient conditions. Compaction shall not begin until the recycled mixture begins to break which may be 30 minutes to 2 hours or more, after the material has been placed. Rolling patterns shall be such that starting and stopping occurs on previously compacted material or the adjacent existing surface. At no time shall rollers stop or start on uncompacted recycled surfaces. Breakdown and intermediate compaction shall be accomplished by a combination of steel drum vibratory rollers and pneumatic tire rollers. The rolling pattern shall be selected by the contractor and continuously monitored and adjusted by the contractor at approximately 500 ton intervals such that the maximum density and required smoothness are achieved. The rolling pattern shall be such that no further increase in density is achieved with additional passes, and cracking of the cold recycled material due to over rolling does not o ccur. The in- place flow test performed in accordance with Arizona Test Method 430 may be used as an indicator to determine if the maximum achievable density is attainable. Water should be uniformly applied to the wheels and drums of rollers, at the minimum rate necessary, along with necessary mechanical means, to prevent recycled material from being picked up. Any pickup shall be immediately removed from the wheels/drums by necessary means and any damaged/scarred areas of cold recycled material repaire d and compacted. Pooling or ponding water on the recycled surface due to excessive spraying or any other reason will not be permitted. Any such areas of standing/excessive water shall be swept/dried as necessary. TABLE OF CONTENTS INDEX 356 As described in Subsection 408-9 of the specifications, field compacted specimens shall be prepared from processed cold recycled material obtained immediately in front of the compaction operation. The specimens shall be compacted in a 6- inch proctor mold in accordance with Arizona Test Method 246 except that no screening of the material is required before compaction. Compaction of the cold recycled material shall be monitored during the rolling operation with a thin lift nuclear density gauge in accordance with Arizona Test Method 412. The wet density determined at each location shall be recorded. Wet density determined by the thin lift nuclear density gauge measurements shall be compared to the wet density of the field compacted specimens. The dry density from nuclear density testing, cal culated by removing the measured moisture content, as determined by AASHTO T 255, from the wet density, shall be compared to the maximum theoretical density provided in the mix design to determine air void content and consistency with the mix design. The wet density of the placed cold recycled material shall be at least 98 percent of the average wet density of the associated field compacted specimens as identified in Subsection 408- 10.02 of the specifications. 408- 7.09 Fog Sealing and Blotter Material Appl ication: Fog coat and blotter material application shall be in accordance with Section 404 of the specifications. A fog coat shall be applied at a rate proposed by the contractor and approved by the Engineer. The operation shall be such that the roadway can be returned to traffic within two hours from the end of cold recycle operations, or as required by the Engineer. 408- 7.10 Opening to Traffic: Prior to opening to traffic, the compacted cold recycled material shall be verified to be of adequate strength under the observation of the Engineer. The results of shear vane testing performed in accordance with Arizona Test Method 429 shall be at least 35 foot -pounds of torque and the results of in- place flow testing performed in accordance with Arizona Test Met hod 430 shall be such that the depression is no greater than 10 millimeters and the height of lateral deformation shall be no greater than 5 millimeters , without bleeding. 408- 7.11 Maintenance: The surface of the recycled pavement shall be maintained in a condition suitable for the safe accommodation of traffic. Any loose aggregate that develops on the surface of the recycled pavement shall be removed by power brooming. Any potholes that develop in areas the Engineer has deemed to be acceptable shall be f illed with hot or warm mix asphalt and compacted. TABLE OF CONTENTS INDEX 357 Any work necessary to maintain the placed and compacted cold recycled material is considered incidental to cold recycling. 408- 7.12 Curing: Cure time will depend on the amount and type of engineered emulsi on used, additional mixing water, recycling additive, and ambient conditions. Sufficient cure is when the moisture content of the cold recycled material is no more than 2.0 percent. The minimum cure time is 3 consecutive days without precipitation. The moisture content of the cold recycled material shall meet the requirements of Subsection 408 -
10.02of the specifications prior to placing the final surfacing and/or
overlay. 408- 7.13 Secondary Compaction: If, in the opinion of the Engineer, adequate compaction was not attained during placement and initial compaction, secondary compaction shall be performed after sufficient cure has been achieved and prior to the final surfacing or subsequent overlay. Secondary compaction shall consist of additional rolling with both pneumatic- tired and steel double drum rollers in static mode only. Secondary compaction shall only be performed when the pavement temperature is at least 80 degrees F. A rolling pattern shall be established with a nuclear thin lift asphalt density gauge. The rolling pattern is the number of passes at which peak density is reached and the requirements of Subsection 408 -7.08 of the specifications have been m et. If no increase in density is realized or the cold recycled mat exhibits cracking, secondary compaction should be immediately suspended or foregone, as approved by the Engineer. Care shall be taken to ensure that the mat is not over rolled. In the event that the requirements of Subsection 408- 7.08 of the specifications are unattainable, the contractor shall consult with the mix designer, emulsion supplier, and quality control supervisor to investigate and determine a potential cause(s) for the failure to meet these requirements. The contractor shall provide an explanation to the Engineer including discussion of the expected performance of the material and if the material should remain in place, be re- recycled, or removed and replaced with dense graded asphaltic concrete. 408- 7.14 Preparation for Surface Treatment: Prior to placement of any required overlay or surface treatment, the completed cold recycled material shall be swept clean of all dirt, debris, loose material, and standing water. If an asphalt overlay is required, tack coat shall consist of emulsified asphalt meeting the requirements of Section 1005 of the specifications; a hot asphalt cement tack coat shall not be used. TABLE OF CONTENTS INDEX 358 408- 7.15 Placement Dates and Weather Requirements: Cold recycling operations shall only occur during daylight hours and between the dates shown below for the average elevation of the project and only when the pavement/RAP temperature is a minimum of 55 degrees F, or as required by the engineered emulsion manufacturer, whichever is greater. Ambient temperature in the shade at the beginning of placement shall be at least 50 degrees F and rising. Cold recycling operations shall cease when the ambient temperature is 60 degrees F and falling. Cold recycling operations shall not be performed when ambient temperatures are expected to drop to below 35 degrees F or exceed 95 degrees F within a 48- hour period after placement. Cold in -place operations shall not begin and will not be allowed to continue when precipitation is expected or forecast to begin within four hours of cold recycling operations. If cold recycled mat temperatures are expected to or do exceed 85 degrees F, high temperature verification of the mixture shall be performed. If at any time pavement temperatures are expected to or do exceed 160 degrees F, cold recycling operations shall cease immediately. Traffic will not be permitted on cold recycled material having a sur face temperature of over 160 degrees F if, in the opinion of the Engineer, there exists the potential for instability. The contractor shall maintain a schedule which allows for overlay or chip seal placement within the allowable temperatures of the desired surface course. The pavement/RAP and ambient temperature requirements may be adjusted by the Engineer provided the engineered emulsion supplier indicates that such adjustment is acceptable and compatible with the specific emulsion supplied to the project . Average Elevation of Project, Feet Beginning and Ending Dates 0 – 3499 3500 – 4999 5000 and over March 1 – November 30 April 1 – October 31 May 1 – September 30
If, in the opinion of the Engineer, extended weather forecasts show conditions which are conducive to commencement of cold recycling operations, cold recycling operations may proceed. 408- 8 Test Strip: The first day of production for each mix design shall include a test strip with production of at least 1, 500 feet but sufficient in size to evaluate and approve the equipment, construction process, workmanship, quality control, and verify that the equipment, materials, and processes proposed meet the requirements of the specification and result in a stable and durable pavement. All quantities of materials used, addition TABLE OF CONTENTS INDEX 359 rates, and the metering and proportioning systems shall be verified to be accurate and within the required tolerances. Should evaluation of the test strip or verification of the metering and proportioning systems not be to the satisfaction of the Engineer, no further cold recycling operations shall occur until the contractor has made necessary corrections and adjustments, at which time, an additional test strip shall be performed. The test str ip shall be performed on mainline where prevailing pavement conditions exist that are representative of the majority of the area to be recycled. During construction of the test strip, the engineered emulsion shall be added at the target rate shown in the mix design and the appropriate rolling pattern, as discussed in Subsection 408- 7.04 of the specifications, shall be established. Once established, the rate of engineered emulsion may be incrementally adjusted by 0.1 percent, but within ± 0.3 percent of th e target rate on the mix design, as determined necessary by the contractor. A new rolling pattern shall be established following any change in the emulsion target rate. Sampling and testing during placement and compaction of the test strip shall be as out lined in Section 408-9 of the specifications. The wet density of the placed cold recycled material shall be at least 98 percent of the average wet density of the field compacted specimens. If a minimum of 98 percent compaction is not achieved, the contractor shall make necessary adjustments and an additional test strip shall be constructed. Once completed, traffic control shall be adjusted to allow traffic on the test strip and the area shall be periodically monitored to identify inadequate stability or r aveling of the cold recycled material caused by apparent excess or deficiency in residual binder content. Failure of the cold recycled material to perform will require re- recycling of the test strip or replacement with dense graded asphaltic concrete, as determined by the Engineer, adjustments to the existing mix design or a new mix design, and construction of an additional test strip. 408- 9 Quality Control and Production Documentation : The contractor shall perform the quality control measures described in Subsection 106.04(C) of the specifications. At the weekly meeting, the contractor shall be prepared to explain and discuss how the following processes will be employed:
extraction, and washing for corrective aggregate;
handling methods; TABLE OF CONTENTS INDEX 360
separation technique, plant feed technique, stockpile pad thickness, and segregation prevention;
calibration, storing method, and addition of admixture;
placement and technique; and
establishing and monitoring of roller patterns. Quality control and production documentation shall be comprehensive and performed on a continuous basis throughout the cold recycling operation with both per iodic verification of quantities and rates and of total daily production or fraction thereof if a significant change in production occurs. A qualified technician, qualified testing laboratory, calibrated field testing equipment, and additional personnel, as necessary, shall ensure that operations and material produced meet the requirements herein. All observations, measurements, adjustments, and corrective actions required to ensure compliance with mix design and specifications shall be documented. Quali ty control shall be performed in accordance with Subsection 408 -9.01 of the specifications and production documentation shall be performed in accordance with Subsection 408-9.02 of the specifications. 408- 9.01 Contractor Quality Control : The contractor shall provide quality control to the extent necessary to determine the properties of the RAP, processed cold recycled material, and compacted cold recycled material to ensure conformance of the cold recycled material with the associated mix design and requirements herein. Minimum sampling and testing requirements are shown below: CONTRACTOR QUALITY CONTROL TESTING REQUIREMENTS TYPE OF TEST TEST METHOD SAMPLING POINT MINIMUM TESTING FREQUENCY Maximum Aggregate Size Determine with Appropriate Sieve At central plant discharge or recycling train windrow One per 1, 000 ft. Gradation Arizona Test Method 240
plant discharge or recycling train windrow Two per each day of production or change in material TABLE OF CONTENTS INDEX 361 CONTRACTOR QUALITY CONTROL TESTING REQUIREMENTS Film Thickness Asphalt Institute MS -2 At central plant discharge or recycling train windrow Two per each day of production or change in material RAP Temperature Probe measurement or IR gun Ahead of the recycling train or RAP stockpile At start of production and every two hours Moisture Content (4) AASHTO T 255 At central plant discharge or recycling train windrow One per 1, 000 ft. Field Compacted Specimens (4) Arizona Test Method 246
Prior to Compaction One per 1, 000 ft. Compaction (4) Arizona Test Method 412
Compaction One per 1, 000 ft. (5) Shear Vane Test Arizona Test Method 429 After Compaction Prior to Opening to Traffic Flow Test Arizona Test Method 430 After Compaction Prior to Opening to Traffic Mat Moisture Content AASHTO T 255 After curing prior to overlay One per 2, 500 ft. Notes:
represent production at the low and high RAP temperatures.
in accordance with Arizona Test Method 241 except that no screening of the material is required.
density gauge. Wet density shall be recorded.
be compared to the wet density of the associated field compacted specimens. The dry density from the nuclear density gauge, calculated by removing the measured moisture content, as determined by AASHTO T 255, from the wet densi ty, shall be compared to the maximum theoretical density provided in the mix design, and the in- place air voids determined.
shallals o be performed for any secondary compaction.
TABLE OF CONTENTS INDEX 362 For the purposes of target rate selection as required in Subsections 408 - 7.03, 408-7.04, and 408- 7.05 of the specifications , sampling ahead of the mill head may be necessary to determine the in- situ moisture content and unit weight of existing asphaltic concrete pavement. Samples of stockpiled RAP may also be necessary for cold central plant recycling. Quality control personnel shall ensure that areas which are designated for exclusion from the cold recycling operation are not milled and do not become incorporated into the cold recycled material. Any debris or materials not accounted for in the mix design shall be identified and brought to the attention of the Engineer. Recycling additive(s), engineered emulsion, and additional mixing water weights and rates, and the dry density of field compacted specimens shall be compared to the mix design to verify consistency with the mix design. If at any time the calculated rates do not reasonably compare to those determined by the computerized metering and proportioning system, action shall be taken to correct or ensure that the system is accurately monitoring and metering the cold recycling operation. If the metering and control systems are determined to be unable to accurately monitor and control the cold recycling operation, cold recycling operations shall cease immediately until such systems have been demonstrated to operate to the satisfaction of the Engineer. 408- 9.02 Cold Recycling Production Documentation: During cold recycling operations, the contractor shall document satisfaction of the Contractor Quality Control requirements and Quality Control Plan, and submit evidence of such to the Engineer weekly, to be included in the Weekly Quality Control Reports as required in Subsection
106.04(C)(6) of the specifications. The evidence shall consist of
samples taken, tests performed, and associated test results, inspections, all verificatio n calculations, Daily Production Reports, and any observations or actions taken pertinent to the cold recycling operation. Failure to include such documentation in the Weekly Quality Control Report will result in the associated report not being accepted. The Daily Production Report shall include documentation of the following:
adequately prepared prior to cold planing/milling. The areas consisting of material designated for exclusion from the cold recycled material and any additional areas for which, exclusion is determined to be necessary, shall be identified and clearly marked on the pavement surface. Areas where excessively deteriorated pavement, unstable pavement, base, or subgrade conditions become apparent, which were not identified and repaired prior to the cold recycling operation, shall be documented and immediately brought to the attention of the Engineer ; TABLE OF CONTENTS INDEX 363
(corrective aggregate and/or cement) shall be monitored, measured, and confirmed to be in accordance with the mix design and specification requirements;
operating properly and maintaining the required depth and width to within t he required tolerances;
aggregate processed through the cold in- place recycling train shall be calculated based on delivery weights of corrective aggregate, unit weight of existing pavement, and volume based on the dimensions milled. This weight shall be compared to the weight of material measured by the computerized metering and proportion system on board the cold in- place recycling train minus any recycling additive and water added to the material ;
measured by the computerized metering and proportioning system shall be compared to the weight of recycling additiv e dispensed by the holding tank or supply vehicle. If added in slurry form, the percent solids determined by the computerized metering and proportioning system shall be compared to the percent solids based on the weight of water and weight of lime used to produce the slurry;
shall be verified to be acceptable prior to the start of each day’s cold recycling operations. The quantity of engineered emulsion measured by the computerized metering and proportioning system shall be compared to the quantity of engineered emulsion dispensed by the holding tank or supply vehicle;
computerized metering and proportioning system shall be compared to the quantity of water dispensed by the holding tank or supply vehicle;
mixing water shall be calculated based on field measurements in items f, g, and h, and compared to the rates determined by the computerized metering and proportioning system ; TABLE OF CONTENTS INDEX 364
deficiency shall be investigated;
cured, and at an appropriate rate as verified by the amount of emulsion applied and area covered;
recycled material ; and
shall be submitted. 408- 10 Acceptance: Com pacted cold recycled material that has been constructed in accordance with the requirements herein and has maintained both stability and surface integrity to the satisfaction of the Engineer, for which test results indicate conformance to the requirements herein, will be accepted at the time of placement of the required surface treatment or overlay. Acceptance will be on a lot basis; a lot being one day’s production. Acceptance will be on the basis of the following:
408- 10.01 Emulsion Content: Acceptance for emulsion content will be determined by measured quantities of materials included in each of, at minimum, four equal sub- lots in each lot’s production. Additional sub- lots will be required to accurately account for adjustments to the emulsion rate during production. The Engineer will verify the total amount of emulsion reported for each sub- lot based on the Daily Production Reports generated from the computer monitoring and metering system on the cold in- place recycling train or in the cold central plant recycling plant and the target rate used during production. The Engineer will compare the required quantity of emulsion to the actual quanti ty of emulsion used. The lot will be considered to be acceptable if the actual quantity of emulsion used in each sub- lot constitutes an emulsion rate within ± 0.3 percent of the target rate(s) designated by the contractor during production. For deficiencies in emulsion content, the contractor may either re- recycle the cold recycled material or completely remove the TABLE OF CONTENTS INDEX 365 unacceptable cold recycled material. Removed cold recycled material shall be replaced with material meeting the requirements of Section 409, 416, or 417 of the specifications, as determined by the Engineer. 408- 10.02 Compaction and Moisture Content: Acceptance for compaction and moisture content will be determined from four cores for each lot taken by the contractor at random locations determined by the Engineer prior to any placement of surface treatment or overlay. No core will be taken from within 1 foot of a longitudinal joint or 100 feet from a transverse joint. Cores shall be taken in the presence of the Engineer by the contractor utilizing base mounted mechanical coring equipment in accordance with the requirements of Arizona Test Method 104 except that compressed air shall be used in place of water. The bulk density and moisture content of each core will be determined by the Engineer i n accordance with Arizona Test Method 415, Vacuum Method. The contractor’s QC shall determine the in- place density of the designated core locations with a thin lift nuclear density gauge in the presence of the Engineer prior to coring. If undisturbed, int act cores cannot be obtained, the density used for acceptance will be that of the nuclear density gauge and moisture content will be determined by the Engineer in accordance with AASHTO T 255 from the recovered cold recycled material. Cold recycled material meeting the requirements herein and compacted to not less than 98 percent of the associated field compacted specimens will be accepted at the bid item price. The core density will be compared to the nearest adjacent field compacted specimen representati ve of the production from where the core was obtained. Cold recycled material not meeting this requirement for compaction will be rejected and shall be corrected by means of additional compaction or re-recycling and re- compacting. If additional effort does not result in acceptable cold recycled material, the material shall be removed and replaced with material meeting the requirements of Section 409, 416, or 417 of the specifications, as determined by the Engineer. The moisture content of the material obtai ned from coring shall be 2.0 percent or less, or if 10 consecutive days without precipitation have occurred, no more than 0.5 percent greater than the moisture content of the existing pavement prior to cold recycling operations. 408- 10.03 Surface Requirements and Tolerances: The recycled asphaltic concrete shall be compacted smooth and reasonably true to the required lanes, grades, and dimensions. TABLE OF CONTENTS INDEX