402Open Graded Friction Course

401.03.14 Shoulder Wedge . The Contractor shall attach a device to the screed of the

paver that confines the material at the end gate and extrudes the asphalt material in such a way that results in a compacted wedge sh ape pavement edge of approximately 30 degrees, but not steeper than 35 degrees. The device shall ma intain contact between itself and the road shoulder surface and allow fo r automatic transition to cross roads, driveways, and obstructions. The device sha ll be used to constrain the asphalt head reducing the area by 10% to 15% increasing the density of the extruded profile. Conventional single plate strike off shall not be used. Short sections of handwork will be allowed wh en necessary for transitions and turnouts, or otherwise authorized by the Engineer. Information on approved devices can be obtained from the State Construction Engineer. If the Contractor has a similar device they want to get approved, the Contractor shall provide proof that the device has been used on previous projects with acceptable results, or construct a test section prior to the beginning of work and demonstrate wedge compaction to the satisfaction of the State Construction Engineer. SECTION 402 - OPEN GRADED FRICTION COURSE

402.01 Description . These specifications include general requirements that are

applicable to Open Graded Friction Course (OGFC). This work consists of the construction of one lift of OGFC in accordance with these specifications and the specific requirements fo r the mixture to be produced and placed in reasonably close conformity with the lines, grades, thicknesses and typical sections shown on the plans or established by the Engineer.

402.01.1 Definitions.

Maximum Sieve Size - Maximum sieve size is the sm allest sieve size at which 100 percent of the aggregate passes. Nominal Maximum Sieve Size - The nominal maximum sieve size is one sieve size larger than the first sieve to retain more than 10 percent of the aggregate. Mechanically Fractured Face - An angular, rough, or broken surface of an aggregate particle created by crushing as determined by ASTM D 5821. Break Point Sieve – The sieve size which separates the coarse and fine aggregate fractions of an OGFC mixture.

402.02 Materials .

402.02.1 Component Materials .

402.02.1 1--General . Component materials will be conditionally accepted at the plant

subject to later rejection if incorporated in a mixture or in work that fails to meet contract requirements.

402.02.1 2--Aggregates . The source of aggregates shall meet the applicable

requirements of Section 703.

402.02.1 2.1--Coarse Aggregate Blend. Mechanically fractured faces by weight of the

combined aggregate blend reta ined on the break point sieve shall be 90 percent two or more fractured faces, as determined by ASTM D 5821. The maximum percentage by weight of flat and elongated particles, maximum to minimum dimension greater than three (3), shall not exceed 20% for OGFC mixtures. This shall be determined in accordance w ith ASTM D 4791, Section 8.4, on the combined mineral aggregate retain ed on the break point sieve. The following table indicates the break poin t sieves for various nominal maximum size OGFC mixes. Mixture Size Break Point Sieve 12.5-mm No. 4 9.5-mm No. 8

402.02.1 2.2--Combined Aggregate Blend. All gradations will be based on percent

passing by weight. The gradation requirements for OGFC mixtures are provided in the following table. Natural sand shall not be used in OGFC mixtures. Sieve Size 12.5-mm 9.5-mm 12.5-mm 100 100 9.5-mm 80-89 90-100 4.75-mm 15-30 15-30 2.36-mm 10-20 10-20 75-m 2-5 2-5

402.02.1 3--Bituminous Materials . Bituminous materials shall meet the applicable

requirements of Section 702 for the grade specified. A PG 76-22 asphalt binder shall be used for all OGFC mixtures. The asphalt content (by weight of total mix) shall be based on the bulk specific gravity of th e combined aggregate blend (G sb) to ensure a constant asphalt binder volume in the mix for durability purposes. The relationship between G sb and the minimum asphalt binder content by weight of total mix is provided in the following table. Combined Aggregate Bulk Specific Gravity, G sb Minimum Asphalt Content (%) 2.40 6.6 2.45 6.5 2.50 6.3 2.55 6.2 2.60 6.1 2.65 6.0 2.70 5.9 2.75 5.8 2.80 5.7 2.85 5.6 2.90 5.5 2.95 5.4 3.00 5.3 Tack coat shall meet the require ments of Subsection 402.03.1.2.

402.02.1 4--Hydrated Lime . Hydrated lime shall meet th e requirements of Subsection

714.03.2 for lime used in soil stabilization.

402.02.1 5--Asphalt Admixtures . Additives for liquid asphalt, when required or

permitted, shall meet the requirements of Subsection 702.08.

402.02.1 6--Polymers. Polymers for use in OGFC shall meet the requirements of

Subsection 702.08.3.

402.02.1 7--Stabilizing Fiber. Stabilizing fiber shall meet the requirements of

Subsection 714.07, with the exception that if mineral fibers are used, the minimum dosage rate shall be 0.40 percent.

402.02.2 Blank.

402.02.3 Composition of Mixtures .

402.02.3 1--General . Unless otherwise specified or permitted, the OGFC shall consist of

a uniform mixture of asphalt, aggregate, st abilizing fibers, hydrated lime and, when required or necessary to obtain desired pr operties, antistripping agent and/or other materials. The total amount of crushed limestone aggregat e shall not exceed 50 percent of the total combined aggregate by weight. Hydrated lime shall be used in all OGFC at the rate of one percent (1%) by weight of the total dry aggregate. The aggr egate, prior to the addition of the hydrated lime, shall contain sufficient surface moisture. If necessary , the Contractor shall add moisture to the aggregate according to the procedures set out in Subsection 401.03.2.1.2. The Contractor shall obtain a shipping ticke t for each shipment of hydrated lime. The Contractor shall provide the District Materi als Engineer with a copy of each shipping ticket from the supplier, including the date, time and weight of hydrated lime shipped. Mixtures will require the addition of an antistripping agent when the Tensile Strength Ratio (MT-63*) and/or the Boiling Water Test (MT-59) fail to meet the following criteria. Tensile Strength Ratio (TSR - MT-63*) Wet Strength / Dry Streng th ................................ 85 percent minimum Interior Face Coating ........................................... 95 percent minimum Boiling Water Test (MT-59) Particle Coating ................................................... 95 percent minimum * MT-63 shall be performed at design air void content of OGFC mixtures rather than seven percent (7%) air voids. Vacuum saturation shall not be required. All other testing parameters shall apply. Reclaimed asphalt pavement (RAP) or crushed reclaimed concrete may not be used as an aggregate component in the production of OGFC.

402.02.3 1.1--Mixture Properties. All mixes shall be designed according to Mississippi

Test Method MT-83. OGFC mixes shall be designed with the Superpave gyratory compactor utilizing an N design of 50 gyrations. The design air voids for all OGFC mixes shall be a minimum of 15.0 percent, as determined by ASTM D 6752 (vacuum sealing method). The ratio of the voids in the coarse aggregate in the compacted mix (VCA mix) to the voids in the coarse aggregate as dete rmined with the dry rodded unit weight test (VCA dr) shall be less than 1.0. The designed mixture shall have a draindown of less than 0.3 percent when tested in accordance with Mississippi Test Method MT -82. The minimum permeability of the mixture shall be 30 meters per day as determined by Mississippi Test Method MT-84. The aged abrasion loss of compacted specimens at the optimum asphalt content shall not exceed 40%, and the unaged abrasion loss of compacted specimens at the optimum asphalt content shall not exceed 30%, as de termined by Mississippi Test Method MT-85.

402.02.3 2--Job Mix Formula . At least 14 working days prior to the proposed use of

each mixture, the Contractor shall submit in writing to the Engineer a proposed job-mix formula or request the transfer of a verified job-mix formula as set forth in the latest edition of the Department’s Field Manual for HMA and MT-83. The job-mix formula shall be signed by a Certified Mixture Design Technician (CMDT). The Department will perform the tests necessary for review of a proposed job-mix formula for each OGFC mixture free of charge one time only. A charge will be made for additional job-mix formulas submitted by the Contractor for review. Review of the proposed job-mix formula will be based on ratio of Voids in the Coarse Aggregate (VCA mix/VCA dr), draindown, permeability, abrasion loss, resistance to stripping, and other criteria specified for the mixture. The mixture shall conform thereto within th e range of tolerances specified for the particular mixture. No change in properties or proportion of any component of the job-mix formula shall be made without permission of the Engineer. The job-mix formula for each mixture shall be in effect until revised in writing by the Engineer. A job-mix formula may be transferred to other contracts in accordance with conditions set forth in the Department's Field Manual for HMA. The Contractor shall not pl ace any OGFC prior to receiving “tentative” approval and a MDOT design number from the Department’s Central Laboratory. When a change in source of materials, unsatisfactory mixture production results (such as segregation, bleeding, shoving, rutting over ⅛ inch, raveling & cracking) or changed conditions make it necessary, a new job-mix fo rmula will be required. The conditions set out herein for the original job-mix formula are applicable to the new job-mix formula.

402.02.4 Layer Thickness . The minimum and maximum laying thickness for OGFC

mixtures are provided in the following table. Mixture Nominal Maximum Size Single Lift Laying Thickness, Inches Minimum Maximum 12.5-mm 1 1¼ 9.5-mm ¾ 1

402.02.5 Contractor's Quality Management Program .

402.02.5 1--General. The Contractor shall have full responsibility for quality

management and maintain a quality control system that will furnish reasonable assurance that the mixtures and all component materials incorporated in the work conform to contract requirements. The Contractor shall have responsibility for the initial determination and all subsequent adjustments in proportioning materials used to produce the specified mixture. Adjustments to pl ant operation and spreading and compaction procedures shall be made immediately when results indicate that they are necessary. Mixture produced by the Contractor without the required testing or personnel on the project shall be subject to removal and repl acement by the Contractor at no additional cost to the State.

402.02.5 2--Personnel Requirements. The Contractor shall provide at least one Certified

Asphalt Technician-I (CAT-I) full-time during OGFC production at each plant site used to furnish material to the project. Sampling shall be conducted by a certified technician or by plant personnel under the direct observation of a certified technician. All testing, data analysis and data posting will be performed by the CAT-I or by an assistant under the direct supervision of the CAT-I. The Contractor shall have a Certified Asphalt Technician-II (CAT-II) available to make any necessary pro cess adjustments. Technician certification shall be in accordance with the Department’s Materials Division Inspection, Testing, and Certification Manual , Section 1.3.3 - MDOT HMA Technician Certification Program. An organizational chart, including names, telephone numbers and current certification, of all those responsible for the quality control pr ogram shall be posted in the contractor's laboratory while the OGFC paving work is in progress.

402.02.5 3--Testing Requirements. As a minimum, the Contractor's quality

management program shall include the following:

402.02.5 4--Documentation. The Contractor shall document all observations, records of

inspection, adjustments to the mixture, and test results on a daily basis. All tests conducted by the Contractor in accordance with Subsec tion 402.02.5.3(g) shall be included in the running average calculations. If single tests are performed as a check on individual OGFC properties, between regula r samples, without performing all tests required in Subsection 402.02.5.3(g), the results of those individual tests shall not be included in the running average calculations for that particular property. The Contractor shall record the results of observations and records of inspection as they occur in a permanent field record. The Contractor shall record all process adjustments and job mix formula (JMF) changes on the air void charts. The Contractor shall provide copies of all test data sheets and the daily summary reports on the appropriate Department forms to the Engineer on a daily basis. The Contractor shall provide a written description of any process change, including blend proportions, to the Engineer as they occur. Information provided to the District Materials Engineer must be received in the Engineer’s office by no later than 9:00 AM the day after the OGFC is produced. Upon completion of the placement of all OGFC on the project, the Contr actor shall provide th e Engineer with the original test reports and control charts in a neat and orderly manner.

402.02.5 5--Control Limits. The following control limits for the job mix formula (JMF)

and warning limits are based on a running average of the last four data points. Item JMF Limits Warning Limits Sieve - % Passing 1/2-inch ± 4.0 ± 3.0 3/8-inch ± 4.0 ± 3.0 No. 4 ± 3.0 ± 2.0 No. 8 ± 3.0 ± 2.0 No. 200 ± 1.5 ± 1.0 Asphalt Content, % -0.3 to +0.5 -0.2 to +0.4 Total Voids @ N Design, % -1.3 to +2.5 -1.0 to +2.0

402.02.5 6--Warning Bands. Warning bands are defined as the area between the JMF

limits and the warning limits.

402.02.5 7--Job Mix Formula Adjustments. A request for a JMF adjustment signed by

a CAT-II may be made to the Engineer by the Contractor. Sufficient testing data shall be submitted with the request to justify the change. The requested change will be reviewed by the State Materials Engineer for the Department. If current production values meet the mixture design requirements, a revised JMF will be issued. Adjustments to the JMF shall conform to the latest edition of the Department’s Field Manual for HMA. Adjustments to the JMF to conform to actual production shall not exceed the tolerances specified for the JMF limits. Regardless of such tolerances, any adjusted JMF gradation shall be within the range given in Subsection 402.02.3.2 for the mixture specified. The JMF asphalt content may only be adjusted after verification for minimum voids, permeability, and abrasion loss.

402.02.5 8--Actions and Adjustments. Based on the process control test results for any

property in question, the following actions shall be taken or adjustments made when appropriate:

402.02.5 9--Trial Section. At the beginning of placement for the lift, th e Contractor

shall construct a trial section of a maximum of a maximum of 250 tons of mix, for the purpose of establishing and evaluating consistent mixture and compaction properties. The Contractor shall determine the production point at which the mix shall be sampled during trial section construction. This sample does not have to be selected by the formal random selection procedures used during actual production, but should be representative of the mix produced. The Contractor (QC) and the Department (QA) will conduct tests for mixture quality. A trial section is considered to be successful if the QC test results are within the Warning Limits (the testing indicates a pay factor of 1.0) and the QC tests compare to the QA tests within the allowable differences set forth in Subsection 402.02.6.2. If the criteria for a successful trial section is not achieved, additi onal trial sections shall be constructed until the criteria is achieved, at which time full prod uction can begin. In the event a successful trial section is not accomplished by the completion of the second trial section, the Contractor will be required to construct additional trial sections at an offsite location. The Engineer reserves the right to have any trial section removed and replaced at no additional cost to the State, if the pay factor for any characteristic for a trial section is less than 0.75. For actual payment purposes, a pay factor of 1.00 will be used for the first and second trial sections allowed to remain in place. Any required offsite trial sections will be constructed at no additional cost to the State.

402.02.6 Standard s of Acceptance .

402.02.6 1--General. Acceptance for mixture quality (Total voids @ N

Design, gradation, and asphalt content) will be based on random samples tested in accordance with the latest edition of the Department’s Field Manual for HMA.

402.02.6 2--Assurance Progr am for Mixture Quality. The Engineer will conduct a

quality assurance program. The quality assurance program will be accomplished as follows:

402.02.6 3--Acceptance Pro cedure for Mixture Quality . All obviously defective

material or mixture will be subject to rejection by the Engineer. Such defective material or mixture shall not be incorporated into the finished work. If the defective material has already been placed in the work, the mate rial shall be removed and replaced at no additional cost to the State. The Engineer will base final acceptance of the asphalt mixture production on the results of the Contractor's testing for total voids, gradation, and asphalt content as verified by the Engineer in the manner described and the uniformity and condition of the completed pavement. Areas of pavement that exhibit nonuniformity or failures (materials or construction related) such as but not limited to segregation, bleeding, shoving, rutting over 1/8”, raveling, slippage, or cracking will not be accepted. Such areas will be removed and replaced at no additional cost to the State. Bituminous mixture placed prior to correctio n for deficiencies in total voids @ N Design, gradation, or asphalt content, as required in Subsection 402.02.5.8 and determined by the Engineer satisfactory to remain in place will be paid for in accordance with the following pay factors times the contract unit price per ton. Pay Factor for Mixture Quality * Item Produced in Warning Bands Produced Outside JMF Limits (Allowed to Remain in Place) Gradation 0.90 0.50 Asphalt Content 0.85 0.50 Total Voids @ N Design 0.70 0.50 * The minimum single payment will apply.

402.02.7 Acceptance Procedure for OGFC Pavement Smoothness. The OGFC will

not be considered a surface lift in the comple ted pavement structure. There shall be no smoothness requirement for OGFC pavements. However, all transverse joints in or abutting the OGFC shall meet a tolerance of 1/8” or less when checked using a 10-foot straight edge.

402.03 Construction Requirements . The Department has adopted the “Hot-Mix

Asphalt Paving Handbook” as the guideline fo r acceptable asphalt construction practices.

402.03.1 Specific Requirements .

402.03.1 1--Weather Limitations . The mixture shall not be placed when weather

conditions prevent the proper handling and finishing or the surface on which it is to be placed is wet or frozen. At the time of placement, the air and pavement surface temperature limitations shall be equal to or exceed 55 F and rising. OGFC placement should be avoided when the paving window, based on temperature, is limited When paving operations are disc ontinued because of rain, the mixture in transit shall be protected until the rain ceases. The surface on wh ich the mixture is to be placed shall be swept to remove as much moisture as po ssible and the mixture may then be placed subject to removal and replacement at no ad ditional cost to the State if contract requirements are not met. 402.03.1.2--Tack Coat. Tack coat for OGFC shall be one from the Department’s APL under the category “Open Graded Friction Cour se (OGFC) Asphalt Tack Materials.” PG 76-22 binder shall meet the requirements of Section 702 of the Standard Specifications. Tack Coat for OGFC shall be applied with a distributor spray bar at the applied rate of between 0.10 and 0.14 gallons per square yard. The application rate of the tack coat shall result in complete and uniform coverage of the underlying lift in which the OGFC will be placed. The tack coat for OGFC should be allowed to break, cool and/or cure until a point in time that the tack coat do es not pick-up or track due to traffic from trucks or the paving equipment. It should be pointed out that breaking, cooling, and/or curing times of the tack coat may vary based on the environmental conditions at the time of placement.

402.03.2 Bituminous Mixing Plants .

402.03.2 1--Plant Requirements .

402.03.2 1.1--Cold Aggregate Storage . The cold storage for hydrated lime shall be a

separate bulk storage bin with a vane feeder or other approved feeder system that can readily be calibrated. The system sha ll provide a means for easy sampling of the hydrated lime additive and verifying the quantity of lime dispensed. The feeder system shall require a totalizer. The hydrated lime additive equipment shall be interlocked and synchronized with the cold feed controls to operate concurrently with the cold feed operation that will automatically adjust th e hydrated lime feed to variations in the cold aggregate feed. A positive signal system shall be installed that will automatically shut the plant down when malfunctions cause an improper supply of hydrated lime or water. The plant shall not operate unle ss the entire hydrated lime syst em is functioning properly.

402.03.2 1.2--Cold Aggregate Feed . The hydrated lime shall be dispensed dry or as a

slurry (1 part hydrated lime to 3 parts water) directly onto the composite aggregate between the cold feed and the dryer. When hydrated lime is introduced dry, a spray bar or other approved system capable of spraying all aggregate with water shall be installed in order to maintain all aggregate at the moisture condition set out in Subsection 402.02.3.1 prior to addition of the hydrated lime. An alternate system for spraying the coarse aggregate stockpiles may be allowed when approved by the Engineer. The approved equipment and methods shall consistently maintain the aggregate in a uniform, surface wet condition. The moisture content of the aggregate-hydrated lime mixture, following spraying and mixing, shall be introduced into the automatic moisture controls of the plant. The aggregate-hydrated lime mixture shall be uniformly blended by some mechanical means such as a motorized "on the belt" mixer or pug mill located between the cold feed and the dryer. Other mixing devices may be used subject to approval by the Engineer. A maximum of forty five (45) percent of the total aggregate blend may be fed through any single cold feed bin. If the JMF calls for more than forty five (45) percent of a specific aggregate, that aggregat e must be fed through two (2) or more separate cold feed bins.

402.03.2 1.3--Dryer . The efficiency of drying aggregates shall be such that the moisture

content of an OGFC mixture shall not exceed 0.50 percent by weight of the total mixture, and the moisture content of any underlying lif ts shall not exceed 0.75 percent by weight of the total mixture being produced. 402.03.2.1.4--Stabilizing Fiber Addition. For batch plants, fibers shall be added (manually or automatic) to either the pugmill or the weigh hopper. At least one aggregate source shall be added prior to the fiber addition, if fibers are added to the weigh hopper. Otherwise, fibers shall be added to the pugmill immediately after the addition of all the aggregate and prior to the addition of the asphalt binder.

402.03.2 1.4.1--Manual Method. Provided it is demonstrated to the satisfaction of the

Engineer that the proper dosage rate of the stabilizing fibers is uniformly distributed into the mix, manual introduction of the fibers is acceptable when a batch plant is used to make the mix. When the fibers are available in prepackaged (weighed) containers, proper dosage may be pre-determined per batch. A device is required to interrupt mixture production and warn the plant operator if the operator manually feeding the fiber fails to introduce it properly. Manual introduction of fibers shall not be used in drum plants.

402.03.2 1.4.2--Automatic Method. The automatic method requires specialized

equipment that can accurately proportion and meter, by weight, the proper amount per batch for batch plants, or continuously and in a steady uniform manner for drum plants. Fiber, pelletized or loose, shall not be fed through the cold feed bins or through the RAP bins. These proportioning devices shall be interlocked with the plant system and controlled to 10 percent of the weight of the fibers required so as to maintain the correct proportions for all production rates and batch sizes. During trial section construction, an equipment calibration check shall be performed to the sa tisfaction of the Engineer that shows the fiber is being accurately metered and uniformly distributed into the mix. These metering devices shall provide in- process high flow (>10 percent or more) and low flow (<10 percent or less) plant operator notificatio n and interrupt the mix production where the fiber rate is not properly controlled. The fiber metering system shall also provide a record of feed rate (weight per time) and include a minimum two-foot long section of translucent pipe for visual confirmation of cons istent flow rates. Care shall be taken to ensure that the fibers are not entrained in the plant’s exhaust system. If there is any evidence of fiber in the bag-house or wet-wa sher fines, the liquid asphalt binder line and/or the fiber line shall be relocated so that the fiber is captured by liquid asphalt binder spray and incorporated into the mix. If ther e is any evidence of clumps of fibers or pellets at the discharge chute, the contr actor shall increase the mixing time and/or intensity. This may entail extending the liquid asphalt binder and fiber feeding lines further into the drum. Note : Various stabilizing fiber suppliers have developed methodology and equipment for metering bulk loose and pelletized fiber into asphalt plants. Whenever the fiber supplier’s recommendations are more stringent th an this specification, the fiber supplier’s recommendations shall control.

402.03.2 1.5--Control of Bituminous Material and Antistripping Agent . Specified

bituminous materials from different manufacturers or from different refineries of a single manufacturer shall not be mixed in the plant's asphalt cement supply system storage tank and used in the work without prior written approval of the Engineer. Approval is contingent upon the Engineer's receipt of three copies of the manufacturer's certified test report(s) from the Contractor showing that the bituminous material blend conforms to the specifications. A satisfactory method of weighing or metering shall be provided to ensure the specified quantity of bituminous material. Provisions shall be provided fo r checking the quantity or rate of flow. Weighing or metering devices shall be accurate within plus or minus one- half percent. The antistripping agent shall be injected into the bituminous material immediately prior to the mixing operation with an approved in-line injector system capable of being calibrated so as to ensure the prescribed dosage. An in-line spigot for sampling of asphalt shall be located between the asphalt storage tank and the antistripping agent in-line injector.

402.03.2 1.6--Thermo metric Equipment . An armored thermometer of adequate range

and calibrated in 5°F increments shall be fixed at a suitable location in the bituminous line near the charging valve of the mixer unit. The plant shall be equipped with an approved dial-scale, mercury-actuated thermometer, pyrometer or other approved thermometric inst rument placed at the discharge chute of the dryer to measure the temp erature of the material. When the temperature control is unsatisfactory, the Engineer may require an approved temperature-recording apparatus for better regulation of the temperature.

402.03.2 1.7--Screens. A 1-inch scalping screen shall be used.

402.03.2 1.8--Dust Collector . The plant shall be equipped with a dust collector

constructed to waste or return collected materi al. When collected material is returned, it shall be returned through a controlling device that will provide a uniform flow of material into the aggregate mixture.

402.03.2 1.9--Safety Requirements . A platform or other suitable device shall be

provided so the Engineer will have access to the truck bodies for sampling and mixture temperature data.

402.03.2 1.10--Blank .

402.03.2 1.11--Truck Scales . The specifications, tolerances and regulations for

commercial weighing and measuring devices as recommended by the National Bureau of Standards [National Institute of Standard s and Technology (NIST) Handbook 44] shall govern truck scales used in the State of Mississippi, except weighing devices with a capacity of ten thousand (10,000) pounds or more used to weigh road construction materials (i.e. sand, gravel, asphalt, fill dirt, topsoil and concrete) shall have a tolerance of one-half of one percent (1/2 of 1%) in lieu of the requirements of Handbook 44 and shall be regulated by the Department. Scales shall be checked and certified by a scale company certified in heavy truck weights by the MDAC. In the case of scales used fo r measurement of materials on Department of Transportation projects, certification shall be performed in the presence of an authorized representative of the Department or a copy of the certification may be furnished for scales that have been checked and certified within the last six months for use on other Department projects and are still in the position where previously tested. Scales that have not been checked and certified under NIST Handbook 44 guidelines, except for the herein modified tolerances allowed, shall be so checked and certified prior to use for measurement of materials on Department of Transportation projects. Tests shall be continued on six month intervals with the test conducted in the presence of an authorized representative of the Department. Truck scales shall be accurate to one-half of one percent of the applied load, shall be sensitive to 20 pounds, and shall have a graduation of not more than 20 pounds. The Contractor may use an el ectronic weighing system approved by the Engineer in lieu of truck scales. The system shall be equipped with an automatic print out system that will print a ticket for each load with the following information: MDOT, Contractor’s name, project number, county, ticket number, load number, pay item number, item description of the material delivered, date, time of day, haul vehicle number, gross weight, tare weight , net weight and total daily net weight. When approved by the Engineer and material s are measured directly from a storage bin equipped with load cells, exceptions may be made to the gross and tare weight requirements. The ticket shall also have a place for record ing the temperature of OGFC mixtures, if applicable, and the signatures of the Department’s plant and roadway inspectors. The load numbers for each project shall begin with load number one (1) for the first load of the day and shall be numbered consecutively without a break until th e last load of the day. The Contractor shall provide the Depart ment with an original and one copy of each ticket. When the ticket information prov ided by the Contractor proves to be unsatisfactory, the Department will use imprinter(s) and imprinter tickets to record load information. All recorded weights shall be in pounds and shall be accurate to within one-half of one percent of the true weight, and the system shall be sensitive to 20 pounds. The Engineer may require random loads to be checked on certified platform scales at no cost to the Department. If the electroni c scales are found to be inaccurate, a re- certification of the scales shall be performed before the Contractor can continue use of the scales. When an electronic weighing system utilizes th e plant scales of a batch plant, the system may be used only in conjunction with a fully automatic batching and control system.

402.03.2 2--Additional Requ irements for Batching Plants .

402.03.2 2.1--Plant Scales. The plant batch scale weight shall not exceed the platform

scale weight by more than one percent (1%). 402.03.2.3--Additional Requi rements for Drum Mixing Plants .

402.03.2 3.1--Plant Controls . The plant shall be operated with all the automatic controls

as designed and provided by the plant manufacturer. If the automatic controls malfunction, brief periods of manual operations to complete the day’s work or to protect the work already placed may be conducted with the approval of the Engineer. During manual operation, the Contractor must continue to produce a uniform mixture meeting all contract requirements.

402.03.2 3.2--Aggregate Handling and Proportioning . A screening unit shall be

placed between the bins and the mixer to rem ove oversized aggregate, roots, clayballs, etc.

402.03.2 4--Surge or Storage Bins . Normally the surge bins will be emptied at the end

of each day's operation. During breakdowns or adverse weather conditions, the material may be stored for a period not to exceed th ree hours in a well-s ealed, well-insulated, heated bin.

402.03.3 Hauling Equipment . The inside surfaces of each vehicle bed shall be coated

with a light application of water and thin oil, soap solution, lime water solution or other approved material to prevent the mixture from sticking. Diesel fuel or gasoline shall not be used to lubricate vehicle beds. Truck beds shall be raised to drain excessive lubricants before placing mixture in the bed. An excess of lubricant will not be permitted.

402.03.4 Asphalt Mixture Pavers . The screed shall be capable of vibrating and heating

the full width of the mixture being placed and shall lay the lift with an automatic control device to the specified slope and grade without tearing, pulling or gouging the mixture surface. Rigid screed and auger extensions sh ould be used when the width of the screed is not adequate to pave a full lane width or full paved width (lane width plus shoulder width). Typically, the end of the auger extension should extend to approximately 18 inches or less from the end plate to en sure uniform mixture placement. Strike-off extensions should not be used for OGFC placement 402.03.5--Rollers . All rollers shall be self-propelled units capable of maintaining a smooth and uniform forward and reverse speed as required for proper compaction. Pneumatic-tired rollers shall not be permitted for compacting OGFC mixes. Rollers shall be equipped with adjustable scrapers, water tanks, mats and a device for wetting the wheels to prevent the mixture from sticking. Adhesion of the mixture to the rollers will not be permitted. The use of diesel fuel or gasoline for cleaning roller wheels, or to aid in preventing the mixture from sticking to the wheels, is prohibited. All rollers shall be in good mechanical cond ition, free from leaking fuels and lubricants, loose link motion, faulty steering mechanism, worn king bolts and bearings. They shall be operational at slow speeds to avoid di splacement of the mixture and capable of reversing direction smoothly and without backlash.

402.03.6 Preparation of Grade . The foundation upon which OGFC pavement is to be

placed shall be prepared in accordance with the ap plicable Section of the Standard Specifications. Unless otherwise directed, tack coat shall be applied to the underlying surface on which the mixture is to be placed. Emulsions, if used, must be allowed to "break" prior to placement of the bituminous mixture. Bituminous mixture shall not be placed agains t the edge of pavements, curbs, gutters, manholes and other structures until the edges lo cated adjacent to the asphalt layer to be placed are sprayed with a thin uniform tack co ating. The tack coat shall be protected until the mixture has been placed. Existing pavements that require preliminary leveling or patching in advance of placing the OGFC mixture shall be sprayed with a tack coat material and then brought as nearly as practicable to uniform grad e and cross section. The material shall be placed by hand or machine in one or more compacted layers approximately two (2) inches or less in compacted thickness. 402.03.7--Blank .

402.03.8 Preparation of Mixture . The temperature of the mixture, when discharged

from the mixer, shall not exceed 340°F. 402.03.9--Material Transfer Equipment. Except for the areas mentioned below, the material transferred from the hauling unit sh all be remixed prior to being placed in the paver hopper or insert by using an approved Materials Transfer Device. Information on approved devices can be obtained from the State Construction Engineer. Areas excluded from this requirement include: temporary wo rk of short duration, detours, bridge replacement projects having less than 1,000 feet of pavement on each side of the structure, acceleration and deceleration lane s less than 1,000 feet in length, tapered sections, transition sections (for width), shoulders less than 10 feet in width, crossovers, ramps, side street returns and other areas designated by the Engineer.

402.03.10 Spreading and Finishing . The mixture shall be spread to the depth and

width that will provide the specified compacted thickness, line, grade and cross section. Placing of the mixture shall be as continuous as possible. On areas where mechanical spreading and finishing is impracticable, the mixture may be spread, raked and luted by hand tools. Immediately after screeding and prior to comp action, the surface shall be checked by the Contractor and irregularities adjusted. When the edge is feathered as in a wedge lift, it may be sealed by rolling. Irregularities in alignment and grade along the edges shall be corrected before the edges are rolled. Hauling, spreading and finishing equipment shall be furnished that is capable of and operated in such a manner that the rolling operation will satisfactorily correct any surface blemishes. The longitudinal joint in the subsequent lift shall offset that in the underlying lift by approximately six (6) inches. However, the joint in the top lift shall be at the centerline or lane line.

402.03.11 Roadway Compaction . Compaction shall be achieved by two to three passes

of a 10 to 12-ton steel wheel roller operating in static mode. Finish rolling to remove any roller marks shall be performed after the mat temperature decreases to 250°F.

402.03.12 Joints . Joints between previously pl aced pavement and pavement being

placed shall be so formed as to en sure thorough and continuous bond. The contact surface of longitudinal joints, excep t hot joints, shall be sprayed with a thin uniform tack coating before additional mixt ure is placed against the previously placed material. 402.04--Method of Measurement. Open Graded Friction Course will be measured by the ton. The weight of the composite mixtur e shall be determined in accordance with the provisions of Subsection 402.03.2.1.11. Bituminous Tack Coat for Open Graded Friction Course shall be measured by the gallon as in accordance with the provisions of Subsections 109.01 and 410.04.

402.05 Basis of Payment. Subject to the adjustments set forth in Subsection 402.02.6.3,

Open Graded Friction Course, measured as pr escribed above, will be paid for at the contract unit price per ton and shall be full compensation for completing the work. Bituminous Tack Coat, measured as prescribed above, will be paid for at the contract unit price per gallon, which price shall be full compensation for completing the work. Payment will be made under the following items: 402-A: Open Graded Friction Course, * - per ton Mixture 402-B: Bituminous Tack Coat - per gallon * 9.5-mm mixture or 12.5-mm mixture SECTION 403 - ASPHALT PAVEMENTS

403.01 Description. This work consists of constructing one or more lifts of asphalt

pavement meeting the requirements of Section 401 on a prepared surface in accordance with the requirements of this section and in reasonably close conf ormity with the lines, grades, thicknesses, and typical cross sections shown on the plans or established by the Engineer. This work shall also include applicable in-grade preparation of the underlying course in accordance with Section 321. The Contractor must select one of the asphalt mixture processes (HMA or WMA) to be used on this project.

403.02 Material Requirements . Materials and their use shall conform to the applicable

requirements of Subsection 401.02.

403.03 Construction Requirements .

403.03.1 General . Construction requirements shall be as specified in Subsection

401.03, except as otherwise indicated in this section or applicable special provisions.

403.03.2 Smoothness Tolerances . Except as noted herein, the finished smoothness of

each lift shall conform to the designated grade and cr oss section within the following tolerances from grade stakes or other grade reference points set at 25-foot intervals: Lower* & Lower* Top Leveling Intermediate Intermediate Surface Lifts Lift Lift Lift Maximum deviation from grade and cross section at any point ........................................ 1/2" 3/8" 1/4" 1/4" Maximum deviation from A 10 foot straight edge ...................... 3/8" 1/4" 1/8" 1/8"