421 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 more than +5.0 percent from the required quantity, as determined in accordance with Subsection 414- 6.04 of the specifications, no payment will be made for the material which exceeds the +5.0 percent, inclu ding asphalt -rubber 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 the asphalt -rubber will be m ade by the ton, including asphalt cement and crumb rubber. The results of a nuclear asphalt content gauge shall not be used to determine the weight of asphalt -rubber material as the basis of payment. Adjustments in payment shall be made in accordance wit h the requirements of Subsection 1009- 2.03 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. PRODUCT: 415- 1 Description: The work under this section shall consist of constructing Asphaltic Concrete (Asphalt -Rubber), hereinafter asphaltic concrete, by providing a mix design meeting the design criteria specified herein, furnishing all materials, mixing at a plant, hauling, and placing a mixture of aggregate materials, mineral admixture, and bituminous material (asphalt -rubber) 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. The contractor shall acquire and make all arrangements for a source or sources of material, furnish a mix design which will meet the design criteria specified hereinafter, and provideal l the equipment, materials, and labor necessary to complete the work. TABLE OF CONTENTS INDEX 422 The contractor shall be responsible for all adjustments to its equipment necessary to properly accommodate the use of asphalt -rubber as a bituminous material. 415- 2 Asphaltic Concrete Mix Design Criteria: Mix designs shall be developed by the contractor. Each mix design shall meet the criteria in Table 415- 1. TABLE 415 -1 ASPHALTIC CONCRETE MIX DESIGN CRITERIA Criteria Requirements Arizona Test Method
Aggregate, %, Minimum 19.0 832
Range 5.0 ± 0.5 832
Rubber, %, Range 0 - 1.0 832
Sieve Size Percent Passing Without Admixture With Admixture 3/4 inch 100 100 1/2 inch 80 - 100 80 - 100 3/8 inch 65 - 80 65 - 80 No. 4 28 - 42 29 - 43 No. 8 14 - 22 15 - 23 No. 200 0 - 2.5 0 - 3.5 415- 3 Materials: 415- 3.01 Mineral Aggregate Source: The contractor shall provide a source in accordance with the requirements of Section 1001 of the specifications, except that sub- paragraph (3) under Subsection 1001- 3.01(B) of the specifications shall not apply. 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. 415- 3.02 Mineral Aggregate: Coarse and intermediate 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. TABLE OF CONTENTS INDEX 423 Fine mineral aggregate shall be obtained from crushed gravel or crushed rock. All uncrushed material passing the No. 4 sieve shall be removed prior to the crushing, screening, and washing operations necessary to produce the specified gradation. The contr actor shall notify the Engineer a minimum of 48 hours in advance of crushing the material to be used as mineral aggregate, so all crushing operations are inspected. Existing stockpile material which has not been inspected during crushing will not be permi tted for use unless the contractor is able to document to the Engineer's satisfaction that the mineral aggregate has been crushed. Any material inspected by the Department as crushed material shall be separated from the contractor's other stockpiles and r eserved for use throughout the project duration. Mineral aggregate shall be separated into stockpiles by the contractor. No individual stockpile usage shall be less than 3 percent of the total mineral aggregate at any time during mix design or production. No individual stockpile shall contain more than 6.0 percent passing the No. 200 sieve when tested in accordance with Arizona Test Method 201. If necessary, the contractor shall wash the mineral aggregate to meet this requirement. Aggregates shall be free of deleterious materials, clay balls, and adhering films or other material that prevent the thorough coating with the asphalt -rubber. Mineral aggregate shall conform to the requirements in Table 415- 2 when tested in accordance with the applicable test methods. TABLE 415 -2 MINERAL AGGREGATE CHARACTERISTICS Characteristics 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 AASHTO T 176 (After thoroughly sieving the sample, no additional cleaning of the fines from the plus No. 4 material is required.) Minimum 55 Uncompacted Void Content Arizona Test Method 247 Minimum 45.0 Fractured Coarse Aggregate Particles Arizona Test Method 212 Minimum 85% (at least two fractured faces) and minimum 92% (at least one fractured face) determined on plus No. 4 material TABLE OF CONTENTS INDEX 424 TABLE 415 -2 MINERAL AGGREGATE CHARACTERISTICS Abrasion AASHTO T 96 100 Rev., Max 9% 500 Rev., Max 40% Carbonates ( 1) Arizona Test Method 238 Maximum 20% Notes:
conditions exist:
surface normally used by traffic; and/ or
subject to traffic for more than 60 days.
Tests on aggregates outlined in Table 415- 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 abrasi on. Mineral aggregate from a source or combination of sources which does not meet the requirements given in Table 415- 2 for combined bulk oven dry specific gravity, and/or combined water absorption (up to a maximum of 3 .0 percent ), but meets the other specified requirements will be considered for acceptance by the Engineer if: a) the total estimated cost of all asphaltic concrete components, using the mix design unit weight, asphalt -rubber content and mineral admixture percentage, does not exceed the t otal amount bid for these items by more than 5.0 percent; or b) a supplemental agreement is executed adjusting the unit prices of asphaltic concrete components such that the total estimated cost does not exceed the total amount bid by more than 5.0 percent . 415- 3.03 Mineral Admixture: Mineral admixture will be required. The amount shall be 1.0 percent, by weight of the mineral aggregate. Mineral admixture shall be Portland cement, blended hydraulic cement, or hydrated lime, conforming to the requirements of Table 415- 3. TABLE 415 -3 MINERAL ADMIXTURE Material Requirement Portland Cement, Type I or , Type II ASTM C150 Blended Hydrated Cement, Type IP ASTM C595 Hydrated Lime ASTM C1097
The certification and acceptance of Portland cement, blended hydraulic cement, and hydrated lime shall be in accordance with ADOT Materials TABLE OF CONTENTS INDEX 425 Practice and Procedure Directive No. 13, "Certification and Acceptance of Hydraulic Cement, Fly Ash, Natural Pozzola n, Silica Fume, and Lime". 415- 3.04 Bituminous Material: Bituminous material shall be asphalt -rubber conforming to the requirements of Section 1009 of the specifications. The type of asphalt - rubber shall be as specified in the Special Provisions. The crumb rubber gradation shall be Type B conforming to the requirements of Section 1009 of the specifications . The percent of asphalt -rubber used sh all be based on the weight of total mix (asphalt -rubber, mineral aggregate, and mineral admixture). In no case shall the asphalt -rubber be diluted with extender oil, kerosene, or other solvents. Any asphalt -rubber so contaminated will be rejected. Any kerosene or other solvents used in the cleaning of equipment shall be purged from the system prior to any subsequent use of that equipment. 415- 3.05 Blotter Material: An application of blotter material may be required following the placement of the asphalt ic concrete and prior to opening the roadway to traffic. The blotter material shall conform to the requirements of Section 404 of the specifications. The blotter material shall be applied in one or more applications for a total application of 2 pounds per square yard. The Engineer may reduce or eliminate blotter material if deemed to be unnecessary. 415- 4 Mix Design: Utilizing mineral aggregate which has been crushed, processed, separated, and stockpiled, a mix design shall be formulated and submitted by the contractor to the Engineer. The mineral aggregate samples used for mix design purposes shall be representative of aggregate materials to be used during production. The mix design shall be based on the mix design criteria and other requirements hereinbefore specified, utilizing asphalt cement, crumb rubber, and mineral admixture of the type and from the sources proposed for use in the production of asphaltic concrete. The mix design shall be prepared by or under the direct supervision of a pr ofessional engineer experienced in the development of mix designs and mix design testing. The mix design engineer shall meet the requirements given in ADOT Materials Practice and Procedure Directive No. 4, “Asphaltic Concrete Mix Design Proposals and Subm ittals”. The mix design shall be provided in a format that clearly indicates all the mix TABLE OF CONTENTS INDEX 426 design requirements and shall be sealed, signed, and dated by the mix design engineer. The mix design shall be prepared by a mix design laboratory that has met the requirements of ADOT Materials Practice and Procedure Directive No. 19, “ADOT System for the Evaluation of Testing Laboratories”. The contractor may propose the use of a mix design that has been developed for a previous project. The proposed mix design shal l 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 aggregate, have not changed since the formulation of the previous mix design. The contractor 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 design 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 shal l prepare and submit a new mix design proposal in accordance 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 that project. The mix design shall contain as a minimum:
person responsible for the mix design testing ;
aggregate ;
source; crumb rubber type, gradation, and source; percent crumb rubber by weight of asphalt cement; asphalt cement binder properties; asphalt -rubber binder properties; blending procedures; and reaction time;
stockpile;
mineral aggregate gradation, and also the gradation with mineral admixture; and TABLE OF CONTENTS INDEX 427
specific gravity of each component, water absorption, sand equivalent, loss on abrasion, fractured coarse aggregate particles, uncompacted void content, percent carbonates (if required), asphalt -rubber absorption, percent air voids, voids in mineral aggregate, and bulk density. Test results used in the formulation of the mix design shall be from testing performed no earlier than 45 days prior to the date the mix design is signed by the mix design engineer. Historical abrasion values may be supplied on sources, provided the testing was conducted within the past two years. The mix design shall be submitted to the Engineer under a cover letter signed by an authorized representative of the contractor. At lea st five working days prior to the start of asphaltic concrete production, the contractor shall provide the Engineer with samples of the asphalt cement, crumb rubber, and asphalt -rubber that are representative of the materials to be used during production. Asphaltic concrete production shall not begin until the Engineer determines the acceptability of the proposed asphalt cement, crumb rubber, and asphalt -rubber. A copy of the mix design and representative samples of the materials used in the mix design shall be submitted to the Engineer for calibration of the ignition furnace, and for the determination of sand equivalent, fractured coarse aggregate particles, and uncompacted void content. Approximately 300 pounds of mineral aggre gate (proportional to the mix design gradation), 3 gallons of asphalt -rubber, and 1 gallon of mineral admixture shall be submitted. The Engineer shall witness the sampling of the mineral aggregate. The mix design and samples shall be submitted to the Engineer at least five working days prior to the start of asphaltic concrete production. The sand equivalent, fractured coarse aggregate particles, and uncompacted void content shall meet the requirements specified in Subsection 415- 3.02 of the specifications. Additional testing of the fine aggregate for uncompacted void content will be re quired if the method of producing fine aggregate is modified. If the mineral aggregate fails to meet the requirements specified herein, asphaltic concrete production shall not commence, and the contractor shall either submit a revised mix design which is r epresentative of the materials produced or correct the deficiencies in the aggregate stockpiles. The Engineer will review the mix design to assure that it contains all required information. If it does not, it will be returned within two working days of receipt of all samples and mix design information, for further action and resubmission by the contractor. TABLE OF CONTENTS INDEX 428 If the contractor elects to change its source(s) of mineral aggregate, or adds or deletes the use of a stockpile(s) regardless of source, the contract or shall furnish the Engineer with a new mix design which meets the requirements specified hereinbefore. If changes are made in the source or type of bituminous material, or the type of mineral admixture, the contractor shall provide verification testing r esults. Verification testing shall be performed at the original mix design asphalt content using the original mineral aggregate, the proposed bituminous material, and/or the proposed mineral admixture. Three specimens shall be fabricated and tested for bulk density, maximum theoretical density, and effective voids. The percent effective voids must be within ± 0.2 of the percent effective voids in the original design and also be within the current effective voids mix design specification limits. Verification testing results shall not replace target values shown in the original mix design. All target values from the original design shall be used in future production with the exception of any self -directed target value changes that are requested. The veri fication process does not ensure that the contractor can meet the target values during production. The contractor may make self -directed target changes to the approved mix design within the limits shown below. Requests for self -directed target changes shall be made in writing and acknowledged by the Engineer prior to start of production for a lot. Self -directed target changes shall meet contract requirements for mix design criteria and grading limits. MEASURED CHARACTERISTICS ALLOWABLE SELF -DIRECTED TARGE T CHANGES Gradation (sieve size): 3/8 inch No. 4 No. 8 ±4% from mix design target value ±4% from mix design target value ±4% from mix design target value Asphalt -Rubber Content ±0.2% from mix design target value Effective Voids None
The contractor may propose target changes to the approved mix design for the Engineer’s approval. The Engineer will determine if the proposed target change will result in mix production that meets the contract requirements for mix design criteria and grading limits. For acceptance purposes, target changes will not be retroactive. In no case shall the approval of mix design changes relieve the contractor of the responsibility for the results obtained by the use of such approved changes. Should a mix design prove unsatisfactory to the contractor during production, the contractor shall furnish the Engineer with a revised mix design. For acceptance purposes, the revised mix design will not be retroactive. TABLE OF CONTENTS INDEX 429 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 preparing a new mix design. If at any time unapproved changes are made in the source of bituminous material, source(s) of mineral aggregate, production procedures, or proportional changes in violation of approved mix design stipulations, production shall cease until a new mix design is developed, or the contractor complies with the approved m ix design. 415- 5 Contractor Quality Control: 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.
thickness, and segregation prevention;
calibration, mix temperature control, storing method, and addition of admixture;
temperature control, segregation and non -uniform placement contr ol, and joint placement and technique; and
establishing and monitoring of roller patterns, and temperature controls. The contractor shall obtain samples and perform the tests specified in the following table: TABLE OF CONTENTS INDEX 430 CONTRACTOR QUALITY CONTROL TESTING REQUIREMENTS TYPE OF TEST TEST METHOD SAMPLING POINT MINIMUM TESTING FREQUENCY Mineral Aggregate for Asphalt Concrete Gradation Arizona Test Method 201 Crusher Belt or Stockpile 1 per stockpile per day Sand Equivalent AASHTO T 176 Crusher Belt or Stockpile 1 per 2, 000 Tons of total aggregate (1) Fractured Coarse Aggregate Particles Arizona Test Method 212 Uncompacted Void Content Arizona Test Method 247 Asphaltic Concrete End -Product Gradation Arizona Test Method 201 or 427 Cold Feed, Hot Bins, Roadway, or Plant 1 per 1, 000 Tons Asphalt - Rubber Content Arizona Test Method 421, 427, or other approved methods Roadway or Plant 1 per 1, 000 Tons Voids Arizona Test Method 410, 415, 417, 424 Roadway or Plant 1 per 1 ,000 Tons each day. Maximum of 4 per day. Compaction Arizona Test Method 412 Roadway 1 per 300 Tons Note:
on mineral aggregate shall be performed based on the anticipated percent use of each stockpile. Samples taken from individual stockpiles may be composited prior to performing the required tests, or testing may be performed on material from each stockpile and the composite test result for each required test d etermined mathematically.
415- 6 Construction Requirements: The contractor shall be responsible for the proportioning of all materials, for the hauling, placing, loading, spreading , and finishing of asphaltic concrete, and for the applying of bituminous material, such as tack coats, prime coats, and provisional seals, all in accordance with the appropriate portions of the specifications. The contractor shall be responsible for the material spread rate and thickness control. TABLE OF CONTENTS INDEX 431 The asphaltic concrete hot plant shall conform to the requirements of Section 403 of the specifications. The temperature of asphaltic concrete upon discharge from the mixer shall not exceed 350 degrees F. 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. Self -propelled paving m achines 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 shall distribute the mixture unifor mly in front of adjustable screeds. Pavers shall be equipped with a screed for the full width being paved, heated if necessary, and capable of spreading and finishing all courses of asphaltic concrete. Pavers shall be equipped with automatic screed controls with sensors for either or both sides of the paver, capable of sensing grade from an outside reference line, sensing the transverse slope of the screed, and providing the automatic signals which operate the screed to maintain the desired grade and transverse sl ope. Failure of the control system to function properly shall be cause for the suspension of the placing of asphaltic concrete. The base or subgrade upon which asphaltic concrete is to be placed shall be prepared and maintained in a firm condition until asphaltic concrete is placed. It shall not be frozen or excessively wet. At any time, the Engineer may require that the work cease or that the work day be reduced in the event that weather conditions, either existing or expected, are anticipated to have an adverse effect upon the asphaltic concrete. Prior to opening to any traffic, the Engineer may require an application of lime water (a minimum of 50 pounds of lime per 2,000 gallons of water). 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. 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 TABLE OF CONTENTS INDEX 432 NTPEP testing, when tested in 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. Longitudinal joints of each course shall be staggered a minimum of 1 foot with relation to the longitudinal joint of any immediate underlying course. When surfacing courses are placed on 10 foot or wider shoulders which are to receive rumble strips, the contractor shall place any longitudinal joints approximately 1 foot aw ay from the travel lane side of the rumble strip. Longitudinal joints shall be located within 1 foot of the center of a lane or within 1 foot of the centerline between two adjacent lanes. Joints shall be formed by a slope shoe or hot -lapped, and shall res ult in an even, uniform surface. Before a surface course is placed in contact with a cold transverse construction joint, the cold existing asphaltic concrete shall be trimmed to a vertical face by cutting the existing asphaltic concrete back for its full d epth of the lift and exposing a fresh face. After placement and finishing of the new asphaltic concrete, both sides of the joint shall be dense and the joint shall be well sealed. The surface in the area of the joint shall conform to the requirements her einafter specified for surface tolerances when tested with the straightedge placed across the joint. All locations where plate samples are taken from the roadway shall be immediately repaired by the contractor utilizing hot asphaltic concrete. All holes where cores are taken shall be repaired within 48 hours after coring using material approved by the Engineer. All holes shall be in a dry condition prior to repair. The patching material shall be thoroughly compacted in the holes by the contractor. 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. Before asphaltic concrete is placed, the surface to be paved shall be cleaned of al l objectionable material and tacked in accordance with the TABLE OF CONTENTS INDEX 433 requirements of Section 404 of the specifications. The cleaning of the surface, the tacking of the surface, and the type of bituminous material used shall be acceptable to the Engineer. The amount of bituminous material used shall be as directed by and acceptable to the Engineer. A light coat of bituminous material shall be applied to edges or vertical surfaces against which asphaltic concrete is to be placed. 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 its paving operations in such a manner to eliminate exposed longitudinal edges over weekends or holidays. 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 asphalt -rubber. Should any one or more of such conditions be evident in the material delivered to the screed unit, the Engineer will order the work to be stopped until conditions are conducive to the delivery of the mater ial in the condition as hereinbefore required. The moisture content of the asphaltic concrete immediately behind the paver shall not exceed 0.5 percent. The moisture content will be determined in accordance with Arizona Test Method 406. 415- 7 Acceptance of Materials: 415- 7.01 General: In addition to the random acceptance samples taken from each lot, the Engineer may sample and reject material which appears to be defective. Such rejected material shall not be used in the work. The results of tests performed on rejected material will not be included with the lot acceptance tests. Acceptance will be on the basis of the following:
TABLE OF CONTENTS INDEX 434 415- 7.02 Sand Equivalent, Fractured Coarse Aggregate Particles, and Uncompacted Void Content of Mineral Aggregate: During asphaltic concrete production, the Engineer shall obtain and test samples of mineral aggregate for the determination of the sand equivalent, fractured coarse aggregate particles, and uncompacted void content. 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. Mineral aggregate will be acceptable for sand equivalent if it meets the minimum requirements specified in Subsection 415- 3.02 of the specifications. The fractured coarse aggregate particles shall meet the minimum requirements specified in Subsection 415-3.02 of the specifications. The uncompacted void content shall meet the minimum requirements specified in Subsection 415- 3.02 of the specifications. Additional testing of the fine aggregate for uncompacted void content will be required if the method of producing fine aggregate is modified. If the mineral aggregate fails to meet the requirements specified herein, operations shall cease and the contractor shall have the option of submitting a revised mix design conforming to the requirements of Subsection 415-4 of the specifications or correcting deficiencies in the aggregate stockpiles. 415- 7.03 Material Spread: A spread lot shall be considered to be one- half shift of production. Lots encompassing more than one project shall be separated in accordance with Subsection 415- 9(D) of the specifications. 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, and tons placed in each 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 mix design bulk density unless a request is made by the contractor to use a production bulk density. If a request is made to use production bulk density, the first three non- rejected lots following the test lot will be used to determine the average production bulk density. All lots placed prior to establishing the average production bulk density shall be calculated using the mix design bulk density. For each new mix design used on the project, a new production bulk density may be requested by the contractor. In addition, if conditions warrant during asphalt TABLE OF CONTENTS INDEX 435 production, the contractor may request establishment of a new average production bulk density. All requests to use a production bulk density shall be made in writing and approved by the Engineer prior to use. The same procedure will be used for determining average production bulk density in all cases. Changes to the bulk density for calculating spread quantities will not be retroactive. The calculated quantity required in each spread lot will be compared to the actual quantity placed. A lot will be considered to be acceptable, with a zero pay factor, if the actual quantity placed varies by no more than -2.0 to +5.0 percent from the requi red quantity. If the quantity in a lot is found to vary from the required quantity by - 2.1 to -12.0 percent, the appropriate pay factor will be determined in accordance with Table 415- 4. This pay factor will be utilized in determining the pay adjustment as outlined in Subsection 415- 9 of the specifications. 415- 7.04 Gradation, Asphalt -Rubber Content, and Effective Voids: A mixture properties lot shall be considered to be one shift's production. In the event a shift’s production is less than 1, 200 tons, multiple shifts may be combined to form a lot. When a lot consists of production from more than one shift, the following conditions apply: at least one sample shall be taken each shift, at least one sample shall be taken every 500 tons, and no mix design or target value changes shall be made within the lot. If changes are made in the mix design or target values, new lots will be established. Four samples of the asphaltic concrete shall be taken for each lot by the contractor, under the observation of the Engineer, at random locations designated by the Engineer. Samples will be taken in accordance with the requirements of Section 2 or 3 of Arizona Test Method 104. The samples shall be delivered to the Engineer immediately after being taken. The minimum weight of the sample shall be 75 pounds. The Engineer will split the sample and save one- half for 15 days after written notification to the contractor of test results for that lot has been made. The material will be tested by the Engineer for the following properties: TABLE OF CONTENTS INDEX SECTION 415 436 Test Property Test Method Asphalt -Rubber Content Arizona Test Method 427 (See Notes 1 and 2 below) Gradation Marshall Density Arizona Test Method 410 Maximum Theoretical Density Arizona Test Method 417 Effective Voids Arizona Test Method 424 Notes:
performed for each mix design, and at any other time the Engineer directs.
corrected in accordance with the paragraph below as required.
For plants providing asphaltic concrete exclusively for the project, the difference between the asphalt -rubber content as measured by ignition furnace testing and the actual asphalt -rubber content shall be determined by the Engineer for each of the first five lots of asphaltic concrete produced for each mix design. If there are less than five lots for the mix design, the total number of available lots shall be used. If approved by the Engineer, a plant may be considered exclusive to the project if an asphalt -rubber tank is dedicated for the shift of asphaltic concrete production. The determination of the actual asphalt -rubber content may include invoice quantities, volumetric tank measurements using a calibrated rod (tank stickings) corrected for temperature, computerized mass- flow meter, and accounting for wasted materials. If a computerized mass- flow meter is used, documentation of its calibration shall be submitted to the Engineer prior to asphaltic concrete production. At any time during asphaltic concrete production, the Engineer may require that a new calibration of the mass- flow meter be performed. If the average difference exceeds ± 0.10 percent asphalt - rubber content between the asphalt -rubber content measured by ignition furnace testing and the act ual asphalt -rubber content, the contractor may request that a correction to the asphalt -rubber content by ignition furnace testing be made. The contractor must make such a request in writing within two working days after receiving the test results for the fifth lot of asphaltic concrete production. If referee testing is performed on a lot of asphaltic concrete for which a correction, based on the actual asphalt -rubber content, was made to the asphalt -rubber content by ignition furnace testing, referee testing shall not apply to the determination of asphalt -rubber content. The correction, once documented and approved by the Engineer, shall be applied to test results from the beginning of asphaltic concrete production through the remainder of asphaltic concrete production using that mix design; however, a new correction may be determined at any time the Engineer believes it is necessary due to a change in material or other circumstances. If the contractor submits a new mix design, a new correction must be established and applied as specified above. For other plants, no correction will be made to asphalt -rubber content values measured by ignition furnace testing. TABLE OF CONTENTS INDEX 437 Acceptance testing results will be furnished to the contractor within four working days of recei pt of samples by the Engineer. The target values for gradation, asphalt -rubber content, and effective voids are given in the contractor's mix design. The Upper Limits (UL) and Lower Limits (LL) of acceptable production of each of the measured characteristics are as follows: Measured Characteristics Gradation (sieve size): LL UL 3/8-inch TV – 6.0 TV + 6.0 No. 4 TV – 6.0 TV + 6.0 No. 8 TV – 6.0 TV + 6.0 No. 200 TV – 2.0 TV + 2.0 Asphalt -Rubber Content TV – 0.60 TV + 0.60 Effective Voids TV – 2.0 TV + 2.0 Note:
Quality Index. Acceptance is controlled by the variability of the produced material and every effort should be made to strive for the applicable target value (TV).
The Engineer will determine the PT for each measured characteristic in accordance with Subsection 415 -9(I) and utilizing Table 415- 4 of the specifications will determine the pay factor for each measured characteristic. In the event the contractor elects to question the mixture property test results, the contractor may request referee testing in accordance with Subsection 415- 9(J) of the specifications. 415- 7.05 Compaction: Asphaltic concrete shall only be placed when the temperature of the surface on which the asphaltic concrete is to be placed is at least 65 degrees F and the ambient temperature is at least 65 degrees F and rising. The placement shall be stopped when the ambient temperature is at or below 70 degrees F and falling. Compaction control shall be the responsibility of the contractor. The number and types of rollers shall be the contractor's responsibility and shall be suffici ent to meet these requirements. All edges shall be rolled by methods approved by the Engineer, while the mixture is still hot. A compaction lot shall be identical to the mixtures properties lot described in Subsection 415- 7.04 of the specifications. Lots encompassing more than one project shall be separated in accordance TABLE OF CONTENTS INDEX 438 with Subsection 415- 9(D) of the specifications. Each lot shall be tested for acceptance. Twenty cores shall be taken for each lot by the contractor, under the observation of the Engineer. Cores shall be taken using wet coring with soapy water to aid in the release of the core from the coring equipment. The Engineer will designate ten random locations within the lot and the contractor shall take two cores at each location; however, if mor e than one shift constitutes a lot, two cores shall be taken from a minimum of two random locations each shift, or as directed by the Engineer. The Engineer will save one core from each location for 15 days after written notification to the contractor of test results for that lot has been made. Randomly selected locations will be determined to the nearest 0.5 foot in the transverse direction and to the nearest 1 foot in the longitudinal direction of the pavement course; however, the outside 1 foot of the unconfined pavement course will be excluded from testing as shown in ADOT Materials Practice and Procedure Directive (P.P.D.) No. 18, “Determining Sample Times and Locations for End Product Asphaltic Concrete”. P.P.D. No. 18 also addresses areas to be excluded relative to longitudinal joints. Cores shall be taken utilizing mechanical coring equipment in accordance with the requirements of Arizona Test Method 104. Cores shall be a minimum of 4 inches in diameter and shall be taken not later than two worki ng days after placement of the asphaltic concrete. The cores shall be delivered to the Engineer immediately upon being taken. The bulk density of each core will be determined by the Engineer in accordance with the requirements of Arizona Test Method 415. The test results will be furnished to the contractor within four working days of receipt of cores by the Engineer. The target value for compaction shall be 7.0 percent in- place air voids. In-place air voids shall be determined in accordance with Arizona Test Method 424. The maximum theoretical density used in the determination of air voids will be the average of the four maximum theoretical densities determined for the lot in Subsection 415- 7.04 of the specifications. The Upper Limit (UL) is 9.0 percent in- place air voids and the Lower Limit (LL) is 3.5 percent in- place air voids. The Engineer will determine the PT for compaction in accordance with Subsection 415- 9(I) and utilizing Table 415- 4 of the specifications will determine the compaction pay factor. In the event the contractor elects to question the core test results, the contractor may request referee testing in accordance with Subsection 415- 9(J) of the specifications. 415- 7.06 Smoothness and Surface Tolerances: All courses of asphaltic concrete shall be compacted as required, smooth and true to the required lines, grades, and dimensions. TABLE OF CONTENTS INDEX 439 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 requir ements shall be met:
under this section of the specifications shall be tested and 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;
section of the specifications, other than the final lift, shall be tested and shall not vary by more than 1/4 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. 415- 8 Method of Measurement: Asphaltic concrete will be measured by the ton for the asphaltic concrete actually used, which will include the weight of mineral aggregate, asphalt -rubber, and mineral admixture. Measurement will include any quantity used in construction of intersections, turnouts, or other miscellaneous items or surfaces. Asphalt -rubber will be measured by the ton on the basis of the asphalt - rubber content determined in accordance with Subsection 415- 7.04 of the specifications for each lot of asphaltic concrete accepted. The average asphalt -rubber content will be multiplied by the number of tons of asphaltic concrete in that lot to determine the amount of asphalt - rubber. If the contractor has requested referee testing, the average asphalt -rubber content will come from the independent testing laboratory results, unless a correction, based on the actual asphalt -rubber content, was made to the ignition furnace test value as allowed in Subsection 415- 7.04 of the specifications. If a correction, based on the actual asphalt -rubber content, was made to the ignition furnace test value, the average asphalt- rubber content determined from the Department's acceptance testing will be used. At the discretion of the Engineer, asphalt -rubber may be measured by invoice quantities, adjusted as necessary for waste. Waste generated from startup of the asphalt plant will be considered to have a binder content of 3.0 percent. In no case TABLE OF CONTENTS INDEX 440 shall the measured amount of asphalt -rubber for payment be greater than the total of the invoice quantities, adjusted for waste. Mineral admixture will be measured by the ton for the mineral admixture actually used in accordance with Subsection 403- 2 of the specifications. 415- 9 Basis of Payment: The accepted quantities of asphaltic concrete, measured as provided above, will be paid for at the contract unit price adjusted by the appropriate pay factors as hereinafter provided. For the purpose of determining acceptability and appropriate pay factors, each unit of asphaltic concrete will be included in three separate lots: a "spread lot" , a "mixture- properties lot" , and a "compaction lot" . The total unit price for any unit of accepted asphaltic concrete will be the contract unit price, adjusted by the applicable spread lot pay factor, mixture- properties lot pay factor, and compaction lot pay factor. The contractor may request to place the first lot of each mix type as a test strip. Requests to place a test strip shall be made in writing and acknowledged by the Engineer prior to start of production. A test strip shall be limited to 1,000 tons and may only be placed on shoulders, ramps, cross roads, or other areas approved by the Engineer. A test strip shall be excluded from the mixture properties lot pay factor and the compaction lot pay factor; however, all other provisions of Subsection 415- 9 of the specifications shall still apply to such areas. The Engineer may exclude asphaltic concrete from the spread lot and from the spread lot pay factor calculations 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. The Engineer may exclude certain locations from the mixture properties lot and/or the compaction lot and from the random sampling used in determining the mi xture properties lot pay factor and/or the compaction lot pay factor should the Engineer determine that the location of the work precludes normal construction operations. 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.
The spread lot pay factor will be determined in accordance w ith Subsection 415-7.03 of the specifications. If the quantity in a spread lot is found to vary by more than +5.0 percent from the required quantity, no payment will be made for the material which exceeds +5.0 percent, including asphalt cement and mineral admixture. If the quantity is found TABLE OF CONTENTS INDEX 441 to vary by more than - 12.0 percent from the required quantity, the spread lot will be rejected.
The mixture properties lot pay factor shall be determined in accordance with the following procedure:
determined as set forth in Subsection 415- 7.04 of the specifications;
the lowest pay factor for the individual measured characteristics for Gradation and Asphalt -Rubber Content ; and
mixture properties lot pay factor shall be the sum of the pay factor determined in (2) above and the Effective Voids pay factor. The negative pay factor for mixture properties shall not exceed $3.00 per ton. If any individual PT value is less than 50, the lot is in reject and the provisions in Subsection 415- 9(E) of the specifications shall apply.
The compaction lot pay factor shall be determined as set forth in Subsection 415- 7.05 of the specifications.
Involving Multiple Projects: When more than one project is included in a single contract, placement during a shift or h alf shift of production may encompass more than one project. In such case, the applicable spread lot pay factor, mixture properties lot pay factor, and compaction lot pay factor for each project shall be determined as follows:
each project utilizing the procedure set forth in Subsection 415- 7.03 of the specifications;
Asphalt -Rubber Content, and Effective Voids will be determined from the results of the random samples taken and tested in accordance with Subsection 415- 7.04 of the TABLE OF CONTENTS INDEX 442 specifications, regardless of which project(s) the samples fall within;
determined from separate sets of core samples f or each project ;
separately for each project in accordance with Subsection 415- 9(B) of the specifications, utilizing the individual pay factors determined in (2) above; and
separately for each project in accordance with Subsection 415- 9(C) of the specifications, utilizing the pay factor determined in (3) above.
Asphaltic concrete included in any mixture properties lot possessing an individual PT value lower than 50 for Gradation, Asphalt -Rubber Content, or Effective Voids will be rejected. Asphaltic concrete included in any compaction lot possessing a PT value lower than 50 will be rejected. Within 15 days after receiving notice that a spread lot, mixture properties lot, or compaction lot of asphaltic concrete has been rejected by the Engineer, the contractor may submit a written proposal to accept the material in place at the applicable maximum negative pay factor(s). Maximum negati ve pay factors are defined as a minus $1.00 per ton for spread lots, minus $5.00 per ton for compaction lots, minus $3.00 per ton for mixture properties lots in reject for gradation only, minus $5.00 per ton for mixture properties lots in reject for asphal t-rubber content and/or effective voids only, and minus $5.00 per ton for mixture properties lots in reject for asphalt -rubber content and/or effective voids and also gradation. Positive mixture properties lot pay factors become zero when the compaction l ot is in reject and the material is allowed to be left in place. In addition, for any mixture properties lot that is in reject due to asphalt -rubber content but allowed to remain in place, payment shall not be made for asphalt -rubber quantities in excess of the upper limit (UL) as determined in Subsection 415- 7.04(A) of the specifications. The proposal shall contain an engineering analysis of the anticipated performance of the asphaltic concrete if left in place. The engineering analysis shall also detail any proposed corrective action, and the anticipated effect of such corrective action on the performance. The engineering analysis shall be performed by an independent professional engineer experienced in asphaltic concrete testing and the development of asphaltic concrete mix designs. If a rejected mixture properties lot or a rejected compaction lot is submitted for referee testing by the TABLE OF CONTENTS INDEX 443 contractor, the 15 days allowed to prepare an engineering analysis will begin upon notification of referee test resul ts. Within three working days, the Engineer will determine whether or not to accept the contractor's proposal. If the proposal is not accepted, the asphaltic concrete shall be removed at no additional cost to the Department and replaced with asphaltic concrete meeting the requirements of these specifications. If the proposal is accepted, the asphaltic concrete shall remain in place at the applicable maximum negative pay factor(s), and any necessary corrective action shall be performed at no additional cost to the Department. The Department reserves the right to suspend the work should any of the following conditions occur:
ten consecutive production lots;
compaction lot pay factors; and/or
negative either for a mixture properties lot or for a compaction lot within any ten consecutive production lots. If the Department elects to suspend the work for any of these conditions, the contractor shall either submit a revised mix design in accordance with Subsection 415- 4 of the specifications, or submit for the Engineer's approval a written engineering analysis. The engineering analysis shall detail the course of action necessary to correct deficiencies in the contractor’s present production methods such that further production can be accomplished without excessive amounts of asphaltic concrete in penalty or rejection. If approved by the Engineer, the revised mix design, or the course of action proposed in the engineering analysis, shall be implemented, and the work may continue. Costs or delays due to the provisions of this subsection are not compensable.
Payment for asphalt -rubber will be made by the ton. Adjustments in payment shall be made in accordance with the requirements of Section 1009 of the specifications .
Mineral admixture will be paid for at the predetermined price established in the Bidding Schedule. TABLE OF CONTENTS INDEX 444
When required in the Special Provisions, payment for smoothness shall be made in accordance with the requirements of Subsection 109.13 of the specifications .
The “Total Percentage of Lot Within UL and LL (PT)” shall be determined in accordance with Subsection 109.11 of the specifications. Pay Factors (PF) shall be determined by entering Table 415- 4 with PT. TABLE 415 -4 PAY FACTORS Material Spread Mixture Properties and Compaction Negative Variance % Pay Factor (Dollars per Ton) PT Pay Factors (Dollar per Ton) Gradation and Asphalt - Rubber Content Effective Voids Compaction 2.1- 3.0 - 0.10 100 0.00 + 2.00 + 2.00 3.1- 4.0 - 0.20 95-99 0.00 + 0.50 + 0.50 4.1- 5.0 - 0.30 90-94 0.00 0.00 0.00 5.1- 6.0 - 0.40 85-89 0.00 - 0.25 - 0.25 6.1- 7.0 - 0.50 80-84 - 0.25 - 0.50 - 0.50 7.1- 8.0 - 0.60 75-79 - 0.50 - 0.75 - 0.75 8.1- 9.0 - 0.70 70-74 - 0.75 - 1.00 - 1.00 9.1- 10.0 - 0.80 65-69 - 1.00 - 1.25 - 1.25 10.1 - 11.0 - 0.90 60-64 - 1.50 - 1.50 - 1.75 11.1 - 12.0 - 1.00 55-59 - 2.00 - 2.00 - 2.25 More than
12.0Reject 50-54 - 2.50 - 2.50 - 3.00
Less than 50 Reject – See Subsection 415- 9(E) See Subsections 415-9(A) and (E)
Within 15 days after written notification to the contractor of test results for a particular mixture properties lot, the contractor may make a written request for referee testing. The referee testing shall be performed by an independent approved laborator y designated by the Department. The testing of the samples will be performed by the independent testing laboratory without knowledge of the specific project conditions such as the identity of the contractor or mix design laboratory, the test results TABLE OF CONTENTS INDEX 445 by th e Department, or the mix design targets for gradation and effective voids. The asphaltic concrete samples previously saved will be tested for the following properties: Test Property Test Method Asphalt -Rubber Content (See Note 1) Arizona Test Method 427 Gradation Marshall Density Arizona Test Method 410 Maximum Theoretical Density Arizona Test Method 417 Effective Voids Arizona Test Method 424 Note:
furnace testing is made in accordance with Subsection 415- 7.04 of the specifications, the asphalt -rubber content shall not be subject to referee testing.
The results of the referee testing will be binding on both the contractor and the Department. Using the referee testing results, the Engineer will determine new PT’s for all characteristics, with the exception of asphalt -rubber content if a correction to the ignition furnace value was made as specified in Subsection 415- 7.04 of the specifications. When referee testing is performed on a mixture properties lot, the referee test result for the average maximum theoretical density will be used to determine a new PT for compaction. The Department will pay for the referee testing; however, if the combined pay factor of the lot (Mixture Properties plus Compaction) does not improve or is reduced, or if either the mixture properties lot or compaction lot remains in reject or is placed in reject, payment to the contractor for asphaltic concrete shall be reduced by the amount of the cost of the referee testing for the mixture properties of that particular lot.
Within 15 days after written notification to the contractor of test results for a particular compaction lot, the contractor may make a written request for referee testing. The bulk density of each of the cores previously saved will be determined in accordance with the requirements of Arizona Test Method 415 by an independent testing laboratory designated by the Department. The testing of the cores will be performed by the independent testing laboratory without knowledge of the specific project conditions, such as the identity of the contractor or mix design laboratory, or the test results by the Department. The percent air voids will be determined in accordance with Arizona Test TABLE OF CONTENTS INDEX