ASPHALT BASE, WEARING, AND PATCHING AND LEVELING COURSES 401.1-DESCRIPTION: This work shall consist of constructing one or more courses of asphalt concrete, mixed mechanically in a plant, composed of aggregate and asphalt material designed in accordance with either the Marshall or Superpave design system as specified in the contract documents, on a prepared foundation in accordance with these specifications and in r easonable close conformity with the lines, grades, weights or thicknesses, and cross sections shown on the Plans or established by the Engineer. The unit of measurement for asphalt concrete will be by the ton, square yard or cubic yard. The work will be accepted in accordance with these Specifications and the applicable requirements of Sections 105, 106, and 109. 401.2-MATERIALS: The materials shall conform to the following requirements: MATERIAL SUBSECTION Coarse Aggregate 703.1 thru 703.3 Note 1 & Note 2 (See MP 401.02.28 for exceptions and additions required for Superpave Items.) Fine Aggregate 702.3 (See MP 401.02.28 for additions required for Superpave Items) Mineral Filler 702.4 Performance Graded Binders 705.5 Note 1 The total shale, coal and other lightweight deleterious material and friable particles shall not exceed 3%. Note 2 When slag is specified in the contract, the coarse aggregate shall be slag which meets the requirements of 703.3, except as amended in this subsection. 401.2.1–Performance Graded Binder Grade: The standard grade for Performance Graded (PG) binders shall be PG 64S -22, any deviation will be noted in the contract documents. PG 64H -22 shall be used on projects specified with over 20 million ESALs over the design life. PG 64S -22 binder may be used in asphalt placed below the top two lifts in any pavement section, scratch course and patching-and-leveling are not identified as lifts. CONSTRUCTION METHODS 401.3-GENERAL: Construction methods to be used in performing the work shall be submitted to the Engineer for review prior to the start of work. This review may require modification of the proposed methods to provide the desired end product. All equipment, tools, machinery, and plant shall be maintained in a satisfactory working condition. 401.4-COMPOSITION OF MIXTURES: 401.4.1-General: The aggregate for use in the designated mixture shall consist of a mixture of aggregate (coarse, fine, reclaimed asphalt pavement (RAP) if desired, or mixture thereof) and mineral filler if required. It shall be the responsibility of the Contractor to determine the percentage of RAP to be used in the mix. The amount and grade of virgin PG Binder to be used in the RAP designs shall be determined in accordance with Materials Procedure (MP) 401.02.24. 401.4.2-Job Mix Formula: Job Mix Formula (JMF) is the specification for a single mix produced at a single plant. This mix may be specific to a single project or be used on multiple projects if the basic design criteria (design compaction level and PG Binder grade) are the same. The Contractor shall submit a proposed JMF for each combination of aggregate and asphalt material for each type of asphalt concrete to be produced. Dependi ng on the design type, the JMF gradations shall be within the tolerances set forth in either Table 401.4.2A or Table 401.4.2B. Marshall mix designs shall be developed in accordance with MP 401.02.22. Superpave mix designs shall be developed in accordance with MP 401.02.28. Each proposed JMF must be documented on the Division Form T400 and the entire JMF package shall be forwarded for review to the District Materials Engineer/Supervisor. The T400 and JMF package shall then be transmitted to the Materials Control, Soils and Testing Division for final review. If the JMF requires revision, it will be returned to the designer through the District. The T400 Form shall contain the following information:
i.Identification of the source and type of materials used in the design. ii. The aggregate blend percentages and the percentage for each sieve fraction of aggregate considered the desirable target for that fraction. iii. The percentage of asphalt binder representing the optimum asphalt content for the JMF submitted, which is to be considered the desirable target percentage. iv. The temperature of the completed mixture at the plant which shall be within ± 25°F of the median mix temperature established by the temperature -viscosity chart or as recommended by the asphalt supplier.
v.The ratio (calculated to the nearest one-tenth percent) of the Fines to Asphalt (FA). For Marshall mixes the ratio is defined as the percentage of aggregate passing the No. 200 (75 µm) sieve, divided by the percentage of asphalt content calculated at the percentage optimum asphalt content of the design. For Superpave mixes the ratio is defined as the percentage of aggregate passing the 75 µm (No. 200) sieve, divided by the percentage of effective asphalt content calculated at the percentage optimum asphalt content of the design. TABLE 401.4.2A Design Aggregate Gradation Requirements for Marshall Mix Designs Type of Mix Base-I Base-II (Patch & Level) Wearing IV Wearing-I (Scratch-I) Wearing-III (Scratch-III) Sieve Size Nominal Maximum Size 1 ½ in (37.5 mm) ¾ in (19 mm) ¾ in (19 mm) 3/8 in (9.5 mm) No. 4 (4.75 mm) 2 in (50 mm) 100 – – – – 1 ½ in (37.5 mm) 90-100 – – – – 1 in (25 mm) 90 max 100 100 – – ¾ in (19 mm) – 90-100 90-100 – – ½ in (12.5 mm) – 90 max 90 max 100 – 3/8 in (9.5 mm) – – – 85-100 100 No. 4 (4.75 mm) – – 47 min 80 max 90-100 No. 8 (2.36 mm) 15-36 20-50 20-50 30-55 90 max No. 16 (1.18 mm) – – – – 40-65 No. 30 (600 µm) – – – – – No. 50 (300 µm) – – – – – No. 200 (75 µm) 1-6 2-8 2-8 2-9 3-11 TABLE 401.4.2B Design Aggregate Gradation Requirements for Superpave Mix Designs Type of Mix 37.5 25 19 Note 1 (Patch & Level) 12.5 9.5 (Scratch) 4.75 (Scratch) Standard Sieve Size Nominal Maximum Size 37.5 mm (1 ½ inch) 25 mm (1 inch) 19 mm (3/4 inch) 12.5 mm (1/2 inch) 9.5 mm (3/8 inch) 4.75 (No. 4) 50 mm (2”) 100 – – – – – 37.5 mm (1½”) 90-100 100 – – – – 25 mm (1”) 90 max 90-100 100 – – – 19 mm (3/4”) – 90 max 90-100 100 – – 12.5 mm (1/2”) – – 90 max 90-100 100 100 9.5 mm (3/8”) – – – 90 max 90-100 95-100 4.75 mm (No.4) – – – – 90 max 90-100 2.36 mm (No.8) 15-41 19-45 23- 49 28-58 32-67 1.18 mm (No.16) – – – – – 30-60 600 µm (No.30) – – – – – – 300 µm (No. 50) – – – – – – 75 µm (No.200) 0-6 1-7 2-8 2-10 2-10 6-12 Note 1 When a 19 mm mix is specified for use as a heavy duty surface mix, it shall be designed as a fine graded mix with the additional requirement of a minimum of 47% passing the 4.75 mm (No.4) screen. If it becomes necessary to change aggregate sources, a new mix design shall be developed and submitted for approval. When using neat (unmodified) PG Binders, the binder source may be changed without requiring a new mix design, but the binder grade must always remain the same for each design. If a source change resul ts in the use of an additive- enhanced modified binder of the same grade, a new mix design will be required. If a modified binder source is changed or if the modification process is changed, a new mix design shall be developed and submitted for approval. A source change to a new location with the original manufacturer/supplier and the original modification process will not require a new mix design. At no time shall different grades of PG Binders be mixed together in the same storage tank. When it is n ecessary to switch to a new binder grade the tank shall be drawn down as far as possible, normally to the top of heating coils, before refilling with the new binder. The new binder shall be circulated thoroughly before restarting production. 401.4.2.1-Warm Mix Asphalt: When the Division allows an approved asphalt concrete design to be produced as warm -mix asphalt (WMA) using the water injection system, the temperature of the completed mixture at the plant may be lowered to an established range that has previously been determined through trial production. The allowable temperature range specified on the approved T400 mix design form shall be adjusted accordingly when producing WMA. In addition, all references to the minimum compaction temperatures in Sections 401.10.3 and 401.10.4 of this specification, may be waived if it can be established that additional density can be obtained at lower temperatures without damaging the pavement. Intermingling of WMA with non WMA materials on the same course should be avoided. If circumstances result in the need for intermingling, it must be approved by the Engineer. Upon approval, the location where intermingling occurs on the project shall be clearly defined and documented by the Contractor and submitted to the Engineer. If the intermingling occurs on a project where the density of the pavement is being controlled by the rollerpass compaction method, then a new test section shall be established on the new material beginning at the point where the WMA and standard asphalt concrete material meet. If the intermingling occurs on a project where the density is controlled via Lot by Lot testing, the location should be clearly marked so that the correct maximum theoretical density can be used. All testing requirements established for standard asphalt concrete mix designs and quality assurance/quality control testing shall also apply to WMA. 401.5-TESTING: 401.5.1-Procedures: AASHTO R 47 Reducing Samples of Asphalt Mixtures to Testing Size AASHTO R 68 Preparation of Asphalt Mixtures by Means of The Marshall Apparatus AASHTO T 11 Materials Finer Than No. 200 (75 µm) Sieve in Mineral Aggregates by Washing AASHTO T 27 Sieve Analysis of Fine and Coarse Aggregates AASHTO T 30 Mechanical Analysis of Extracted Aggregate AASHTO T 164 Quantitative Extraction of Asphalt Binder from HMA AASHTO T 166 Bulk Specific Gravity (Gmb) of Compacted Asphalt Mixtures Using Saturated Surface-Dry Specimens AASHTO T 168 Sampling Bituminous Paving Mixtures AASHTO T 209 Maximum Specific Gravity and Density of Asphalt Mixtures AASHTO T 245 Resistance to Plastic Flow of Asphalt Mixtures Using Marshall Apparatus AASHTO T 308 Asphalt Binder Content of Asphalt Mixtures by the Ignition Method (Test Method A) AASHTO T 312 Preparing and Determining the Density of Asphalt Mixture Specimens by Means of the Superpave Gyratory Compactor AASHTO T 355 Standard Method of Test for In-Place Density of Asphalt Mixtures by Nuclear Methods ASTM D5581 Resistance to Plastic Flow of Bituminous Mixtures Using Marshall Apparatus (For Base-I Marshall Designs) MP 700.00.06 Aggregate Sampling Procedures 401.6-CONTRACTORS QUALITY CONTROL: 401.6.1-Quality Control Testing : Quality control of bituminous as phalt is the responsibility of the Contractor. The Contractor shall maintain equipment and qualified personnel including at least one certified Asphalt Plant Technician at each plant. The technician shall be in charge of all plant quality control activitie s such as mix proportioning and adjustment and all sampling and testing activities necessary to maintain the various properties of asphalt within the limits of the specification. The Contractor shall maintain necessary equipment and qualified personnel i ncluding at least one certified Asphalt Field and Compaction Technician at each project during paving operations. Additionally, a certified Asphalt Field and Compaction Technician with certification to perform nuclear density testing of asphalt pavements s hall perform all testing necessary to assure compaction of the asphalt meets specification requirements. The Contractor, shall design a workable Quality Control Plan, detailing the type and frequency of sampling and testing deemed necessary to measure and control the magnitude of the various properties of the asphalt governed by these specifications. This plan, prepared in accordance with MP 401.03.50 shall be submitted to the Engineer for review prior to production of material under this specification. 401.6.2-Job Mix Formula (JMF) Field Verification : For each JMF, a mix design field verification shall be conducted during the first days of plant production. For Marshall designs, the verification shall be in accordance with the guidelines established in MP 401.02.27. For Superpave, designs it shall be in accordance with MP 401.02.29. The field verification is for the purpose of demonstrating that the JMF can be produced within the specified tolerances set forth in the MP. If t he mix cannot be produced within these requirements, a new mix design will be required. 401.6.3-Quality Control Testing Requirements: After the JMF design field verification has been successfully completed, sampling frequency and test requirements for quality control shall be as set forth in MP 401.02.27 for Marshall designs and MP 401.02.29 for Superpave designs. If the Division determines that a mix cannot be consistently produced within the tolerance limits of the specified design properties, approval of the mix may be revoked and the contractor will be required to provide a new mix design. 401.6.4-Compaction: Projects shall be tested for compaction in accordance with the Lot - by-Lot test method described in Section 401.6.4.2 if the project limits meet all of the following requirements:
1.Measured roadway width greater than sixteen (16) feet
2.Total design overlay thickness of pavement greater than or equal to 1.5 inches.
3.Total projects length greater than or equal to 0.5 miles, excluding skip paving. If a project does not meet the above criteria, testing for compaction shall be in accordance with the Rollerpass test method described in Section 401.6.4.3. In addition, areas of Trench Paving, Pavement Widening, and Pavement Repairs shall be tested in accordance with the Rollerpass test method or to the satisfaction of the Engineer. When asphalt is placed in areas that require a non -uniform thickness and tapers to a thin edge including patch and level and scratch, acceptance testing of the material is not required. Compaction shall be accomplished with a minimum of eight (8) roller passes prior to reaching the temperature specified in section 401.10.4. A pass shall be defined as the entire roller traversing a spot on the pavement. Compaction shal l be performed by a three -wheel (steel) roller or pneumatic-tire roller. Acceptance testing is not required on areas which are too narrow to be compacted with the roller use for the mainline paving, as defined in the contractor’s QC plan; such areas shal l be compacted to the satisfaction of the Engineer. 401.6.4.1-Density Testing : All Gauge standardization procedures, calibration procedures and all Density testing conducted shall be in accordance with AASHTO T355 - Standard Method of Test for In -Place Density of Asphalt Mixtures by Nuclear Methods. Testing shall be conducted in the backscatter position and follow AASHTO T355 with the exception that no gauge rotation will be required. All gauge tests shall be conducted with the source end of the gauge in the direction of paving. The Gauges used for both QC and QA, shall also have a gauge comparison tested as prescribed in section 401.6.4.1.1. 401.6.4.1.1-Gauge Comparison: For purposes of an accurate comparison, nuclear gauges used for QC and QA shall be compared using the following procedure. If an alternate gauge is brought to the project, repeat the following procedure. Note, this process is required for informational purposes however d ensity readings for Acceptance testing will not be adjust ed to compensate for any differences in readings between gauges. The gauge used for the Contractor’s quality control testing shall be compared with the gauge used for the Division’s verification testing at the same locations.
1.Standardize both gauges according to AASHTO T 355.
2.Take five (5) one-minute wet density readings with each gauge in the backscatter position at three randomly located positions within the initial 500 feet of paving.
a.Locations shall be at least 100 feet from the initial construction joint and a minimum of one (1) foot from the edge of the pavement.
3.The range of the five readings at each location shall not exceed 25 kg/m 3. If the readings exceed this range, perform a new set of five readings. A gauge should not be used if the repeatability of the gauge is not within this range.
4.Utilize the average of the 15 readings to note the difference between the gauges to be used for QC and QA. The Contractor shall take note of this difference whilst performing QC testing. All documentation shall c onsist of original wet density readings as shown on the gauge, no offset is permitted to be entered into the gauge.
a.Difference = QA Gauge – QC Gauge [note sign] 401.6.4.2-Lot-by-Lot Testing: Density of the traveled lanes, shoulders, and Longitudinal Joint will be accepted in the field on a lot by lot basis. Lots will be established cumulatively and will be specific for each JMF.A normal lot size shall not exceed 1000 linear feet of paving, unless operational conditions or project size dictates otherwise. Each lot shall consist of five equal sublots. A standard sublot shall be 200 linear feet. Sublots shall be tested with randomly located nuclear density tests. If the remaining footage of the final two lots of a project combine to be less than 2000 linear feet following the following:
1.If the length is greater than 1000 feet but less than or equal to 1500 feet combine length into a single lot and, divide its length into five equal sublots;
2.If the remaining length is greater than 1500 feet and less than 2000 feet, divide the length into two equal lots with five equal sublots in each lot. Breakdowns or stoppages of short periods due to such causes as weather or equipment failure will not be considered as reason to adjust the lot size. The original lot will be continued when work resumes. Relative density shall be calculated based on the Maximum Specific gravity from the Division approved JMF or the Maximum Spec ific Gravity established under section 401.6.2, Job Mix Formula Verification, whichever is more recently established. 401.6.4.2.1-Mat Density: Compaction testing for the mat density shall be performed for all traveled lanes and shoulders and will be evaluated based on an Upper Specification Limit (USL) of 97.0% relative density and a Lower Specification Limit (LSL) of 93.0% relative density. The average mat density of the Lot shall be calculated as the average of the sublot results. Acceptance of Ma t Density shall be in accordance with Section
401.13 3.
401.6.4.2.2-Joint Density: Longitudinal joint density testing shall be performed on all constructed joints between traveled lanes. Testing of a longitudinal joint constructed between a travel lane and a shoulder is not required. Joint density testing is not required until both lanes of the joint are constructed. The first lane constructed shall be referred to as the cold side and the second lane shall be referred to as the hot side. Joint density testing shall be conducted on the hot side, with the gauge positioned four (4) inches from the constructed joint. Only longitudinal joints constructed on the surface course shall be subject to density testing. Longitudinal joint density testing shall be accepted in the field on a lot by lot basis as described in Section 401.6.4.1. Compaction testing for the joint density will be evaluated based on an Upper Specification Limit (USL) of 97.0% relative density and a Lower Specification Limit (LSL) of 90.0% relative density. The average joint density of the Lot shall be calculated as the average of the sublot results. Acceptance of joint density shall be in accordance with Section 401.13.3. 401.6.4.3-Roller Pass Testing: A Rollerpass Control Section shall be completed on a daily basis, when roadway conditions change where they would affect the compaction effort, or when the Engineer determines the current rollerpass is unsatisfactory. A rollerpass shall be established prior to the mat reaching the temperature specified in section 401.10.4. If a project does not meet the criteria in section 401.6.4, testing for compaction shall be in accordance with the rollerpass test method described in Section 401.6.4.2. In addition, areas of trench paving, pavement widening, and pavement repairs shall be tested in accordance with the rollerpass test method or to the satisfaction of the Engineer. A rollerpass shall be conducted in the following manor:
1.The Rollerpass Control Section shall be conducted 100 feet beyond the initial transverse construction joint. If an additional rollerpass is required by the Engineer conduct it immediately.
2.Apply four passes with the breakdown roller (a pass shall be defined as the entire roller traversing a spot on the pavement) to the roadway, then conduct two randomly located nuclear density testing within the section; record the results, the average, and the mat temperature at each test location.
3.Apply an additional two passes and repeat the nuclear density testing in the same locations; record the results, the average, and the mat temperature at each test location.
4.Repeat step 3 until one or more of the following conditions occur: (a) less than 5 kg/m3 increase occurs between the average of two sets of readings, (b) the density of the material exceeds 97.0% Gmm, (c) one of the two test location “breaks over” (i.e. shows a decrease in density) after exceeding 92.0% of Gmm, or (d) the temperature of the mat has fallen below 175 °F.
5.Compute the Percent of Gmm using the average of the two readings and record on the worksheet. If the mat begins to show signs of distress (such as excessive surface aggregate breakage or mat cracking) before reaching 175 °F, then discontinue rolling and record the number of roller passes completed befo re the stress signs occurred. If a tender mix, as defined in Section 3.3, is encountered the Contractor may be allowed to continue rolling at lower temperatures if it can be demonstrated that additional densification can be achieved at a lower temperature without causing any pavement distress. Once the control section is completed, the density shall be equal to or greater than 92.0% of Gmm. If the density does not meet 92% of Gmm, repeat the procedure above immediately. If after two control sections the density still does not meet 92% of Gmm, contractor shall apply the number of passes associated with the highest percent density, minimum of 8 passes, unless the Engineer determines more appropriate means. To help with this decision, an evaluation may be made of the existing pavement condition and any density test results obtained prior to construction of the test section will be reviewed. If the density within the control section meets 92% of Gmm conduct a proving section in the proceeding 1000 feet. Wit hin the proving section, apply the established number of passes and conduct five randomly located nuclear density tests. The average of these five tests shall exceed a minimum density of 92% Gmm and be within ±50.0 kg/m 3 of the average wet density determined in the Rollerpass control section. If this is not achieved a new rollerpass section shall be conducted. All data shall be submitted the Engineer on associated Rollerpass forms. 401.7-VERIFICATION TESTING: 401.7.1-Acceptance Testing of Asphalt Concrete: Acceptance testing of asphalt is the responsibility of the Division. For Superpave mixes, the acceptance sampl ing and testing requirements for the mixture shall be as set forth in MP 401.02.29. 401.7.2-Surface Tolerance: Final smoothness testing of all new Asphalt surfaces shall be in accordance with Section 720. When compaction is completed on the course, it shall present a uniform surface, true line and grade, conforming to the cross section shown on the Plans. When tested with a straightedge of approximately ten ( 10) feet in length and a template of the specified dimensions, the finished base course shall not show a deviation greater than ¼ inch and the finished wearing course shall not show a deviation from the required surface greater than 3/16 inch. The Contractor shall provide the straightedge and template for checking the surfaces and an employee to use them under the direction of the Engineer. Any irregularity of the surface exceeding the limits specified shall be corrected. Depressions which develop after th e initial rolling shall be corrected by loosening the mixture and adding new material. High places shall be corrected by removing excess material. Areas of completed courses found to be defective shall be removed and replaced with approved mixtures laid in accordance with these specifications, and no additional compensation will be allowed for materials used or work involved in replacing defective areas. 401.7.3-Lot by Lot Compaction : Acceptance testing of mat and joint density is the responsibility of the Division. The Division will conduct density acceptance testing in accordance with section 401.6.4.1. Acceptance activities will be accomplished by conducting testing completely independent of the quality control activities. 401.7.3.1-Mat Densit y: Within a lot of materials offered by the contractor for acceptance, locate one random test. Perform a single 1 -minute test in accordance with section 401.6.4.1. Compare the density to the specification range. If the value is within the range, the lot is accepted for density. If the density result is outside the specification range, divide the lot into five equal sublots and randomly locate a test site within each sublot. Average the five sublot results and utilize section 401.13.3 to determine any required price adjustments. 401.7.3.2-Joint Density: If a joint density lot is to be tested, it will be tested with the corresponding Mat lot. Testing of a joint density lot shall follow section 401.7.3.1. 401.7.4-Thickness: When a uniform thickness of three (3) inches or more is specified, excluding resurfacing, cores shall be taken to verify the thickness of the compacted pavement. Cores will be taken by the Division at random locations. The sampling frequency shall be approximately five cores per 2,000 feet of two -lane construction, except that the sampling frequency shall normally be limited to a minimum of five and a maximum of 50 cores per project. The Division may elect to waive coring for short projects of less th an 1,000 feet in length or for projects where a paving mat of uniform thickness cannot be expected (for example: tapered paving mats or pavement widening projects). The Division may also elect to take additional cores when needed to resolve problems related to pavement thickness. The thickness shall be considered acceptable if one or both of the following criteria are met:
a.The average thickness equals or exceeds the specified thickness.
b.The average thickness is less than the specified thickness, but the difference is not statistically significant at the 95% confidence level. (Standard one tail “t” test at 0.05 significance). The calculated ‘t’ value shall be less than or equal to the standard ‘t’ value at the 95% confidence level. The method for calculating Criteria ‘B’, shall be as follows: 95t t Where: 95t = value from standard “t” table for 95% confidence level t x x s n s = − −1 xs = specified thickness = average thickness n = number of samples s x x n n= − − 2 ( ) x = individual core thickness If the average thickness is less than specified and is determined to be significant as determined by criteria ‘B’, the Division shall decide on a course of action as described in Section 401.13.4. 401.8-WEATHER RESTRICTIONS: Bituminous asphalt shall only be placed when the surface is dry and when weather conditions are such that proper handling, finishing, and compaction can be accomplished. In no case however, shall asphalt be placed when the surface temperature is below the minimum established in Table 401.8. TABLE 401.8 Course Thickness Minimum Surface Temperature 3 inches and over 35 °F Note 1 1.5 to 2.9 inches 40 °F Less than 1.5 inches 50 °F Note 1 In lieu of 35 °F, a minimum air temperature of 40 °F shall be used when paving directly on an aggregate base, subbase, or subgrade. In addition to the above surface temperature requirements, no wearing courses shall be placed when the air temperature is less than 40°F. 401.8.1-Cold Weather Paving: When the air temperature falls below 50° F or the surface temperature falls below 60° F the provisions for cold weather paving shall apply. Paving shall be performed so that the transverse j oints in adjacent lanes shall be no more than fifty (50) feet apart at the end of each day’s paving operations. The surface temperature shall be taken a minimum of once every hour and shall be taken in all shaded areas. The temperature requirements as listed in Table 401.8 shall apply. It shall be the Contractor ’s responsibility to monitor the declining surface temperature to insure that material delivery from the plant be terminated so as to allow that all material can be placed prior to the surface temperature falling below the surface temperatures listed in Table 401.8. The temperature of the delivered material and the mat temperature at the time final density is obtained shall be taken for every truck load. These temperatures shall be in accordance with Section 401.10.3 for delivered material and 401.10.4 for the mat temperature at the time final density is obtained. 401.9-EQUIPMENT: 401.9.1-Plants: All plants in West Virginia producing asphalt for the Division shall provide documented evidence of compliance with current requirements of the West Virginia Air Pollution Control Commission. All plants which are not in West Virginia but producing asp halt for the West Virginia Division of Highways shall provide documented evidence of compliance with current requirements of the laws and regulations of the State in which they are producing, applicable to air pollution. All plants shall meet the general requirements set forth in AASHTO M 156 unless it can be demonstrated to the satisfaction of the Engineer that a consistent quality mix can be produced with modifications to any of these requirements. 401.9.2-Dust Collector: An efficient dust collecting system shall be provided to prevent the loss of fine material. The material collected may be returned to the mixture at a uniform rate or discarded. 401.9.3-Truck Scales: Truck scales shall be provided at each Plant, except that truck scales are no t required at properly calibrated automatic batching plant facilities which are equipped with digital printout equipment, and which load the trucks directly from the mixer or the weigh hopper in a surge or storage bin. A person designated as a weigher sh all be provided by the producer. The weigher shall certify that the weight of the asphalt, as determined either by the truck scales or from the digital printout of the batch weights, is correct. Each truck shall be weighed empty prior to each load, exce pt at automatic batch plants approved to operate without truck scales. All truck scales shall be mounted on solid foundations which will insure them remaining plumb and level. Approval and sealing of scales shall be conducted at the frequency determined by the West Virginia Division of Labor, Bureau of Weights and Measures, and when the plant is moved, or upon the request of the Engineer. The Engineer shall be notified of any scale malfunctions when material is being furnished to Division of H ighways projects. The Division may, at its option, accept inspection and sealing by out-of-state agencies when the mixing plant is located outside West Virginia. A digital recorder shall be required on all truck scales. The digital recorder shall produ ce a printed record of the gross, tare and net weights, and the time, date, truck identification, and project number. Provision shall be made for constant zero compensation and further provision shall be made so that the scales may not be manually manipulated during the printing process. The system shall be interlocked so as to allow printing only when the scale has come to rest. In case of breakdown of the automatic equipment, the Engineer may permit manual operation for a reasonable time, normally not to exceed 48 hours, while the equipment is being repaired. The scales shall be of sufficient size and capacity to weigh the loaded trucks that are used for delivery of asphalt from the plant. 401.9.4-Test Weights: As part of its standard equipment, e ach plant which proportions aggregate by weight shall provide a minimum of ten 50-pound test weights for the purpose of maintaining the continued accuracy of its weighing equipment. Plants which proportion asphalt material by weight shall furnish, in addition to the above, one five pound test weight. 401.9.5-Surge and Storage Bins: During the normal daily operation of the plant, asphalt may be stored in a surge or storage bin for a maximum of 12 hours, provided the bin has received prior evaluation and acceptance through the District plant inspection. The resulting temperature of the material at time of placement and compaction shall be sufficient to comply with 401.10.3 and 401.10.4 Longer silo storage times, up to 24 hours, may be permitted for dense graded asphalt if the storage silo is insulated and/or heated to assure that the proper mix temperature is maintained. The gates at the bottom of the storage silo shall be adequately heated and sealed when the asphalt is held for the extended period of time. An inert gas system may be used to purge the silo of oxygen to prevent oxidation of the asphalt. The asphalt delivered from the storage silo shall meet all of the specification requirements. When asphalt is stored for the extended time period, it shall not be used until the temperature has been checked and the asphalt has been visually inspected for hardening of the mix and stripping of the asphalt from the aggregate. Approval of the extended storage time may be revoked if it is determined through inspection and/or testing that the extended storage is having a detrimental effect on the asphalt. Loading of trucks through the storage bin will only be permitted when a minimum 25 -ton buffer of material is being maintained or an amount as recommended by the bin manufacturer, means shall be provided for loading the trucks directly from the mixer when the storage bin is not in operation. 401.9.6-Inspection of Equipment and Plant Operations: The Engineer shall have access to the plant to assure th e adequacy of the equipment in use, to inspect the conditions and operation of the plant, to verify weights, to verify the proportion and character of materials, and to determine if specified temperatures are being maintained in the preparation of the mixture. 401.9.7-Trucks for Transporting Mixture: The inside surfaces of trucks shall be thinly coated with a National Transportation Product Evaluation Program (NTPEP) approved asphalt release agent. The use of diesel fuel, kerosene, or similar solvent -based products which can dissolve the asphalt film from the aggregate particles will not be permitted. Any commercial release agent which can be certified by NTPEP as harmless to the mix may be used; however, the Division reserves the right to restrict an y release agent that is shown to cause problems during placement of the mix. In the case of mixtures composed of PG Binders which contain polymer modification, truck surfaces should be coated with a release agent recommended by the binder supplier. All e xcess coating material shall be removed from the truck bed prior to loading the asphalt. All truck beds shall be insulated with approved material. No trucks shall be used which cause segregation of the materials, which show large oil leaks, or which cause undue delays in delivery of material. All trucks shall be provided with a waterproof cover and a hole in the body for the purpose of conveniently checking the temperature of the load. Covers shall be suspended slightly above the mixture, shall extend over the sides of the truck, and shall be securely fastened to eliminate air infiltration and to prevent water from coming in contact with the mixture. 401.9.8-Laboratory: A testing facility or laboratory, as described below, shall be provided within r easonable proximity of the asphalt plant. Plant operations must be visible from within the laboratory. The laboratory shall be of sufficient size to hold all laboratory test equipment and supplies with adequate floor space to allow the technicians to test samples in an efficient manner. The laboratory shall be furnished and maintained with adequate ventilation, heat, light, water, sink and drainage, electrical or gas outlets, or both, work table, shelves, and supply cabinets. The laboratory shall be s upplied with the equipment and materials listed below and these shall be maintained to meet the applicable requirements of AASHTO or ASTM:
i.Hot plate, gas or electric. ii. Large ovens (as needed for heating and drying samples), gas or electric. iii. Unit weight container, ½ cubic foot. Required for slag only. iv. Balances of sufficient capacity and accuracy for conducting specified tests and plant calibration.
v.Thermometers: dial type, liquid -in-glass, and digital as required for conducting standard test procedures and monitoring mix temperatures. Digital thermometers shall be equipped with an appropriate sturdy probe that can be pushed into a sample of hot asphalt to check the temperature of the mix. vi. Standard Gilson shaker or equivalent, with screens. vii. Ro-Tap shaker or equivalent, with eight (8) and/or twelve (12) inch diameter screens. viii. Sample splitters for fine and coarse aggregates. ix. Miscellaneous items (including sample splitting trowels, scoops, square point shovel, aggregate sample pans, heat resistant gloves, measuring rules, brushes, flashlight, timing devices, and glassware as needed).
x.Expendable supplies necessary for performance of tests. Xi Equipment for determining the maximum specific gravity of asphalt mixtures as specified in AASHTO T 209. xii. Equipment for determining the in -place density of asphalt mixtures meeting the requirements of MP 401.05.20. xiii. Non-contact infrared thermometer accurate to ± 2°F. xiv. Equipment for dete rmining the bulk specific gravity of asphalt mixtures using saturated surface dry specimens complying with AASHTO T 166. xv. Marshall equipment necessary to comply with AASHTO R68, AASHTO T 245 and ASTM D5581, including a calibrated load frame having recording capabilities (digital or analog) and compaction hammers. (Marshall designs only) xvi. Asphalt content ignition oven with built -in scale and printer meeting the requirements of AASHTO T 308, Test Method A. xvii. Calibrated Gyratory compa ctor meeting requirement of AASHTO T 312 with computer (including software for data acquisition and test calculations) and primer. Compactor must be calibrated to the internal angle in accordance with AASHTO T344 with annual verification (Superpave designs only). 401.9.9-Asphalt Paving Equipment: Asphalt paving equipment shall be self -contained and of sufficient size, power and stability to receive, distribute and strike -off the asphalt mixture at rates and widths commensurate with the typical sections and other details shown on the plans. The paver shall be provided with an activated screed or strike-off assembly equipped to be heated. Approval of the paver by the Engineer will be based on the demonstrated capability of the equipment to place the mixture to the required cross -section, profile and alignment in an acceptable, finished condition ready for compaction. The paver shall be equipped with means of preventing the segregation of the coarse aggregate particles when moving the mixture from the paver hopper to the paver augers. It shall also be capable of pushing a sufficient amount of the mixture under the auger gearbox to prevent streaking or tearing of the mat. Some paver models may require the installation of a manufacturer retrofit kit or equipment modification to accomplish this. Specialized equipment or hand methods approved by the Engineer may be employed to spread the asphalt mixture where the use of standard full scale paver is impractical due to the size or irregularity of the area to be paved. Pavers shall be equipped with mechanical or automatic grade and slope controls. The use of automatic grade and slope controls with a traveling straight edge shall be required only when specified on the Plans or in the Proposal. Both the grade and slope controls shall be in working order at all times. In the event of failure of the automatic controls, the Contractor will be permitted to finish the day ’s work using manual controls but will not be allowed to resume work the following day until the grade and slope controls are in proper working order. 401.9.10-Compaction Equipment: Compaction shall be performed by self -propelled steel-wheeled or pneumatic-tired rollers. The use of either vibratory or oscillatory type rollers is acceptable. Pneumatic rollers shall be equipped with skirt ing around the wheel area to prevent heat loss to the tires and tire pads. Hand -held rollers or vibrating plates may be used in small inaccessible areas as approved by the Engineer. Prior to use on any project, the roller shall be inspected to see that it is in good mechanical condition. The total weight, weight per inch of width (steel-wheeled), and average ground contact pressure (pneumatic-tired) shall be documented in the contractors QCP in accordance with MP 401.
401.10 Paving Operations:
401.10.1 Cleaning and Sweeping: Immediately prior to the arrival of the paving mixture,
the existing base or surface shall be thoroughly cleaned by the use of to ols and equipment as may be required to remove all mud, dirt, dust, and other caked or loose material foreign to the type of treatment or surface being placed. The cleaning shall be done to a minimum width of one foot on each side beyond the width of the surface being placed.
401.10.2 Patching and Leveling and Scratch Courses: Compaction of patching and
leveling and Scratch Courses shall be performed with three -wheel (steel) or pneumatic -tire rollers.
401.10.2 1-Patching and Leveling : A tack coat sh all be applied to the existing
pavement prior to placing patching and leveling. Patching and leveling shall be placed at various locations throughout the project to remove irregularities in the existing pavement such as dips, or to raise the outside edge of the existing pavement to provide a uniform template prior to placing a base or wearing course. Patching and leveling shall not be placed as a continuous layer or course over the full width and length of the project.
401.10.2 2-Scratch Course: A tack coat shall be applied to the existing pavement
prior to placing a scratch course. The scratch course shall be placed to the limits designated on the plans. Scratch course shall be placed with a paving machine. The paving machine screed shall be set to drag on the high areas of the existing pavement, only depositing material in ruts and other depressions. The wearing course, or at least one lift of base course, should be placed over the scratch course prior to maintaining traffic in the lane where the s cratch course has been placed. All repairs to a scratch course due to traffic damage shall be at the contractor’s expense.
401.10.3 Spreading and Finishing: Before spreading any material, the contact surfaces
of curbs, gutters, manholes, and of adjacent Portland cement concrete pavement edges shall be painted or sealed with asphalt material. Exact edge of pavement, except on concrete, shall be established b y a string or chalk line for a distance of not less than 500 feet ahead of the spreading operation. For mixes produced with neat (non-modified) asphalts (which may include PG64H-22, PG 64S-22, PG 58H-28, and PG 58S-28) the temperature of the mixture at the time of placement shall be within the temperature requirements of the JMF. The JMF temperature range shall be within the master temperature range of 250° and 338°F unless otherwise specified by the asphalt supplier. The mix temperature shall be monitored by inserting a dial type thermometer into the mix through the hole in the truck bed. The temperature of the completed mix, when measured at the plant, shall be within the tolerance as established by the JMF. The first load which demonstrates temper atures outside of that range shall be accepted, provided that the temperature is still within the master temperature range. No additional loads of material shall be run out until necessary steps are taken to reestablish the temperature of the mix within t he plant tolerance. When measured at the project site, the temperature of the mix shall be within the tolerance established by the JMF. The first truck load of material which demonstrates temperatures outside of that range or any trucks in transit at tha t time shall be accepted provided temperatures are within the master temperature range. Any truckload of material which exceeds the master temperature range may be rejected by the Engineer. However, the plant shall immediately be notified that no additional loads of material are to be dispatched until necessary action is taken to reestablish temperature within JMF specification limits. When the surface temperature falls to within 10°F of the weather restrictions of Table 401.8, the mix temperature may b e increased up to a maximum of 338°F unless otherwise specified by the asphalt supplier. The temperature of each truckload of material shall be monitored for compliance. Any truckload of material which exceeds this maximum temperature may be rejected by the Engineer. Mixes produced with asphalts that contain modifiers for high or low temperature performance enhancement shall meet the temperature requirements recommended by the asphalt supplier, which will be referenced on the JMF.
401.10.4 Rolling Procedure: Shoulders, ramps, and similar areas shall be compacted in
the same method as the mainline. During rolling, roller wheels shall be kept moist with only enough water to avoid picking up material. Fuel oil on roller wheels or pneumatic tires is not allowed. Rollers shall move at a slow but uniform speed with the drive roll or wheels nearest the paver. If rolling causes material displacement, the affected area shall be loosened at once with lutes or rakes and restored to its original grade with loose material before being re -rolled. Heavy equipment, including rollers, should not be permitted to stand on the finished surface before it has thoroughly cooled or set. Mat temperature shall be measured using a non -contact infrared thermometer. The required density shall be obtained prior to the mat temperature reaching 175°F. The Contractor shall be allowed to lower this temperature to 165° F if they can demonstrate during the first day of placement of each lift on each project that additional dens ification can be achieved without causing any pavement distress.
401.10.5 Joints: The longitudinal joint in any layer shall offset that in the layer
immediately below by approximately six (6) inches; however, the joint in the top layer shall be at the centerline of the pavement if the roadway comprises two lanes of the width, or at lane lines if the roadway is more than two lanes in width. The transverse joint in any layer shall offset that in the layer immediately below by approximately six feet. All transverse joints between existing and new pavement shall be “heeled-in” to the existing surface at the beginning and at the end of the project and at all other locations where the new pavement terminates against an existing pavement. Transverse joints b etween one day’s production and the next shall be carefully constructed and shall be formed by cutting back into the existing section to expose the full depth of the course. All joints shall be squared up to the full vertical depth of the course to be placed, and a tack coat of asphalt material shall be applied. Joints adjacent to curbs, gutters, or adjoining pavement shall be formed by transporting back sufficient hot material to fill any space left uncovered by the paver. The longitudinal joint between adjacent mats shall be set up to a sufficient height to receive the full compactive effort from the rollers and shall be tacked prior to placing adjacent material. Transverse joints shall be checked for smoothness with a ten foot straight edge prov ided by the Contractor. All surface irregularities shall be corrected prior to proceeding with paving operations.
401.10.6 Safety Edge: When the total specified lift thickness of pavement is 1.5 inches
or greater, asphalt safety edge shall be constructed on the outside pavement edge. The device utilized shall be a model listed on Division Approved Product Listing. The resulting finished surface of the safety edge shall be sufficiently consolidated so as to show no segregation, or raveling of the aggregate and shall have the same surface profile and texture of the compacted mat surface. Safety edge is not to be used through intersections, against curb or barrier, or when directed by the Engineer. The paving operation shall allow for automatic and/or manual transitions at cross roads, driveways, and intersections. The Engineer may allow short sections of handwork for transitions at driveways, intersections, interchanges, and bridges.
401.11 Protection of Pavement and Traffic Control:
The Contractor shall be responsible for the protection of asphalt surfaces from damage by their equipment and personnel. When the construction of asphalt surfaces is undertaken on projects under public traffic and the road surface is sixteen (16) feet wide or greater and the ADT is 400 or gre ater, the Contractor shall place no passing signs, Interim pavement markings, and Temporary pavement markings to delineate the edge line, centerline, and/or lane line of the roadway as required herein and in the project plans. The provision of Section 636 : Maintaining Traffic shall apply.
401.12 Method of Measurement:
Asphalt concrete will be measured by the ton, or square yard. For projects paid by the ton, the quantity will be determined by the Contractor from the total weigh slips for each vehicle load weighed upon an approved standard scale or from digital printout slips from an automatic batching plant, and certified by the Contractor as correct. For projects paid by the square yard, the quantity will be determined by the Plan Quantity as provided for in the proposal unless otherwise directed by the Engineer. Any patching or leveling mixture placed on a subbase or base course constructed in the same Contract with the asphalt items shall be at the expense of the Contractor. No additional compensation will be allowed for the material or any work incidental to its placement. No additional measurement is necessary nor will addition compensation be allowed for the placement of Safety Edge.
401.13 Basis of Payment:
The quantities determine as provided ab ove, will be paid for at the contract unit price for the items listed below, which prices and payment shall be full compensation for furnishing all the materials and doing all the work herein prescribed in a workmanlike and acceptable manner, including all labor, tools, equipment, field laboratory, supplies, and incidentals necessary to complete the work. The conditioning, cleaning, and sweeping of the existing base or underlying surface shall be considered as part of the construction of the appropriate items listed in 401.14, and no additional compensation will be allowed for "Cleaning and Sweeping". There will be no additional compensation for tack coat material used for minor (spot) areas to be patched and leveled; the cost of this tack coat material wi ll be included in the unit bid price for the “patching and leveling” Item. There will be no additional compensation for Interim Pavement Markings.
401.13.1 When a Lot of asphalt material is found not in compliance with the tolerance
requirements of MP 401.02.27 or MP 401.02.29, it shall be subject to a price adjustment in accordance with the criteria established in this MP.
401.13.3 A Lot of asphalt pavement shall have its price be adjusted in accordance with
Table 401.13.3A using Formula -1. If a Lo t of asphalt pavement is associated with a Longitudinal Joint Lot its price shall be adjusted in accordance with Table 401.13.3A and Table 401.13.3B using Formula-2. The longitudinal joint density determined in accordance with Section 401.6.4 shall represent the Lot on which the joint density testing was performed. Any price adjustment for joint density shall be applied to that Lot only. Use Formula -1 on the first lane paved before a longitudinal joint is constructed. Use Formula-2 when both mat and joint density testing is required on a project. FORMULA-1: Lots requiring only mat density testing: Lot Price Adjustment (Mat only) = (unit price) X (Lot quantity) X (mat density price adjustment % from Table
401.13 3a)
FORMULA-2: Lots requiring both mat and joint density testing: Lot Price Adjustment (Mat + Joint) = (unit price) X (Lot quantity) X [(mat density price adjustment % from Table
401.13 3A) + (joint density price adjustment %
from Table 401.13.3B)] TABLE 401.13.3A Adjustment of Contract Price for Pavement Mat Density Percent of Density Percent of Contract Price to be Paid Greater than 97 % Note 1 93% to 97% 100 92% 99 88% to 91% = 99 – 4*(92% - Percent density) Less than 88% = 84 – 10*(88% - Percent density) Note 2 Note 1: Mat density slightly above 97% is normally only a problem if it leads to asphalt flushing on the surface of the mat or rutting due to an unstable mix. The Division will make a special evaluation of the material and determine the appropriate action. Note 2: When the density is less than 93%, the mat will be more susceptible to accelerated deterioration and a decrease in the expected service life of the pavement. For mat densities less than 88%, the percent of Contract Bid Price will be decreased by an additional 10% per percentage of mat density less than 88%, unless a Special evaluation performed by the Division determines a more appropriate action. TABLE 401.13.3B Adjustment of Contract Price for Pavement Joint Density Percent of Joint Density Percent Adjustment Greater than 97 % Note-3 90% to 97% Note 4 0% 89 % Note 5 -1.0% 88 % Note 5 -3.0% Less than 88 % Note 5 and 6 Note 3: Density greater than 97% is normally only a problem if it leads to asphalt flushing on the surface of the mat or rutting due to an unstable mix. The Division will make a special evaluation of the material and determine the appropriate action. Note 4: If the longitudinal joint density is determined to be less than 92% on 25% or more of the total project LOTs, then the Contractor shall be required to seal the joint a minimum of 3” on each side of the joint with a heated PG 64S-22 binder (or approved equivalent) on the entire project at no additional cost to the Division. Note 5: Any longitudinal joint densities determined to be below 90% the Contractor shall be required to seal the joint a minimum of 3” on each side of the joint on the entire project with a heated PG 64S -22 binder (or approved equivalent) at no additional cost to the Division Note 6: Density values less than the minimum specified 90% will be more susceptible to accelerated deterioration of both the joint and the surrounding pavement. For Joint densities less than 88%, the percent of adjustment will be decreased by an additional 6% per percentage of joint density less than 88%, unless a Special evaluation performed by the Division determines a more appropriate action.
401.13.4 When a Lot of asphalt pavement is determined to be statistically non-conforming
in accordance with Criteria ‘B’ of Section 401.7.4, the Division will review the plans and project records to determine if there is an acceptable explanation for this deficiency. If it is determined that a deficiency does exist, one of the following adjustments may be used. If the deficiency is less than ¾ inch, the Division may choose to accept the material at a price equal to the bid price times the ratio of the average thickness divided by the specified thi ckness. If the deficiency is ¾ inch or greater, the Division may require that an additional lift of material [specified to the nearest ¼ inch of the deficiency] be placed at the Contractor’s expense. Retesting of the overlay will be at the expense of the Contractor in accordance with MP 109.00.20.
401.14 Pay Items:
ITEM DESCRIPTION UNIT 401001-* “design method” Asphalt Base Course, “aggregate type”, Type “mix type” Ton 401002-* “design method” Asphalt Wearing Course, “aggregate type”, Type “mix type” Ton 401003-* “design method” Asphalt Patching And Leveling Course, “aggregate type Ton 401007-* “design method” Asphalt Scratch Course, “aggregate type”, Type ‘mixed type” Ton 401017-* Asphalt Pothole Repair, Type Ton * Sequence number “design method” shall be either Marshall or Superpave “aggregate type” shall be either stone and gravel or slag “mix type” from Table 401.4.2A or 401.4.2B
Referenced in this section
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Source: Standard Specifications for Roads and Bridges, 2023 Edition. Pages 177–197 of 1,006. View official source ↗