New Hampshire Department of Transportation Standard Specifications – 2016
Description
1.1These specifications include general requirements that are applicable to all types of plant mix asphalt pavements
irrespective of the gradation of aggregate, kind and amount of asphalt binder, or pavement use. Deviations from these general requirements will be indicated in the specific requirements for each type.
1.2These specifications provide for the use of reclaimed asphalt pavement material in certain specified mixtures.
1.3This work shall consist of the construction of one or more courses of asphalt pavement constructed on a prepared foundation
in accordance with these specifications and the specific requirements of the type under Contract. The work shall be in reasonably close conformance with the lines, grades, thickness, and typical cross-sections shown on the plans, within the tolerances specified or established by the Engineer.
1.4These specifications provide for both method and quality control/quality assurance (QC/QA) specification work. Sections
under the heading Performance Requirements (QC/QA) are applicable on QC/QA items only. Sections marked Quality Control (QC/QA) Method are applicable for non -QC/QA items and those portions of QC/QA items that are not measured for pay adjustment. All sections under the heading General are for use with all items.
1.5Performance Requirements (QC/QA).
1.5.1 The work will be accepted under Performance Requirements (QC/QA) provisions in accordance with these Specifications and the applicable requirements of Section 106.
reconstruction projects in rural areas or on reclamation projects in rural areas.
with maintenance of traffic phasing, projects with intersecting streets, projects with pavement tapers, bridge projects with short approach paving, projects where there are many manhole/drainage structures or driveways (generally in urban and suburban areas). QUALITY/PAY FACTORS TO BE ASSESSED Tier 1 Tier 2 Asphalt Content and Gradation X X Cross Slope X Density X X Ride Quality X Thickness X Materials
2.1Aggregates – General.
2.1.1 Aggregates shall be uniform quality durable pebbles or fragments of rock, with or without sand or other inert finely divided mineral aggregate. All material shall be free from clay balls, organic matter, deleteri ous substances, and an excess of flat or elongated pieces as specified in ASTM D 4791. Washing will not be required, except when aggregate plants do not produce clean material by the dry process method. In order to obtain uniformity of color and appearance of the pavement throughout the project, the aggregate for all the wearing courses shall be obtained from the same material source. Sufficien t material shall be on hand prior to starting daily operations to ensure uninterrupted processing for the working day. 2.1.2 Fine aggregate shall consist of sound durable particles of sand, crushed stone, or a combination thereof. Fine aggregate shall be free from clay balls and injurious amounts of organic matter. Stone screening shall be produced from ston e at least equal in quality to that specified for coarse aggregate. 2.1.2.1 Fine aggregate may be 100 percent manufactured aggregate. 2.1.3 Mineral filler shall conform to AASHTO M 17 except that 100 percent shall pass the No 16 sieve, waiving the requirement for the No. 30 sieve. 2.1.4 Coarse aggregate shall be crushed stone or crushed gravel and shall have a percentage of wear as determined by AASHTO T 96 of not more than 45 percent unless otherwise specified by Contract item. In each stockpile, not less than 50 percent by weight of the particles retained on the No. 4 sieve shall have at least one fractured face. Stockpiles consisting of a New Hampshire Department of Transportation Standard Specifications – 2016 blend of crushed stone and crushed gravel will be permitted so long as the overall consisten cy of the stockpile is reason ably maintained and the lesser portion of coarse aggregate material does not exceed 10 percent of the total. This percentage shal l be determined on the portion of the total sample by weight that is retained on the No. 4 laboratory sieve. 2.1.4.1 Coarse aggregate for High Strength HBP shall be crushed stone and shall have a percentage of wear as determined by AASHTO 96 of not more than 45 percent wear.
2.2Bituminous Materials – General.
2.2.1 Bituminous materials used for asphalt cement binder shall meet the properties specified in AASHTO M 320. The grade of asphalt cement binder to be used will be specified in a Special Provision contained in the Proposal. Asphalt cement shall not be air blown or contain any form of used, recycled or re-refined oil. 2.2.1.1 The unit bid price for hot bituminous pavement containing failing asphalt binder shall be assessed a 10% reduction for one temperature grade below the specified high temperature grade or one temperature grade above the specified low temperature grade. The penalty will be applied to all tonnage produced with the non-compliant binder. When the binder failure is non-compliant by two grades or more, as described above, the Contractor shall be required to remove and replace all non - compliant material at the Contractor’s expense, or at the Engineer’s discretion, may be allowed to leave the tonnage in place at a unit price reduction of 50%. 2.2.2 Liquid binder samples shall be obtained by plant personnel in the presence of the Inspector/Technician. Samples shall be obtained during each day’s production. 2.2.3 Producers and suppliers of asphalt binders shall comply with the requirement of AASHTO R 26. Asphalt binder suppliers shall have a quality control plan approved by the Bureau of Materials and Research that complies with AASHTO R 26. 2.2.3.1 All suppliers of PG binder shall certify that the PG binder supplied for use on Department projects does not contain used, recycled or re-refined oil.
2.3Approval of Materials - Method Requirements.
2.3.1 At least five working days in advance of the date of starting operations, the Bureau of Materials & Research may request that representative samples of all materials proposed for use be submitted for testing.
2.4Composition of Mixtures - General.
2.4.1 Hot mix asphalt shall be composed of a mixture of aggregate, filler if required, and asphalt binder. The several aggregate fractions shall be sized, uniformly graded, and combined in such proportions that the resulting mixture meets the grading requirements of the job mix formula. The Contractor shall use the Volumetric Mix Design Method in AASHTO Standard Practice R 35 as modified herein. 2.4.2 The Contractor shall have the option of utilizing asphalt pavement removed under the Contract, if any, or old asphalt pavement from an existing stockpile or supplying all new materials for the production of asphalt pavement or any combination of the foregoing. If the job mix formula uses recycled materials, the mix shall meet the requirements of Reclaimed Asphalt Pavement as specified in 2.9. 2.4.3 The Department allows the use of recycled binder in mix designs, up to 1.0% Total Reused Binder (TRB) without any change in asphalt binder requirements as long as the mix design meets all volumetric mix design criteri a. When a design has been completed using the maximum allowable percentage of TRB, one point verifications may be performed using decreasing percentages of TRB. If the design is not validated using a decreased amount of TRB, a new design will be required .
2.5Job Mix – General.
2.5.1 When a new volumetric mix design is required, the Contractor shall use the Volumetric Mix Design Method in AASHTO Standard Practice R 35 to develop a mix that meets the associated design criteria. The Mix design shall follow the procedure detailed in AASHTO with the following exceptions: Amend Table 1 Superpave Gyratory Compaction Effort to read as follows: Design ESALs
0 < 5 6 50 75 >5 7 75 115 Add the following:
New Hampshire Department of Transportation Standard Specifications – 2016 Minimum Binder Content 50 Gyration 75 Gyration 3/8” 6.0% 5.8% 1/2” 5.5% 4.9% 3/4” 4.6% 4.6% 1” 4.3% This required minimum asphalt content is based on the use of aggregate with a specific gravity of 2.65 to 2.70. The minimum asphalt content requirement may be adjusted when aggregate with a higher specific gravity is used, or the minimum may be adjusted at the Engineer’s discretion if it is believed to be in the best interest of the Department. Amend Table 3 in AASHTO M 323, referenced in AASHTO R 35, to read as follo ws: Table 401-1 –Design Control Points* Standard Nominal Maximum Aggregate Size Sieves 1” 3/4” 1/2” 3/8” No. 4
Max. Min. Max. Min. Max Min. Max. Min. Max. Min. Inch Percentage by Weight Passing Criteria (Control Points) 1-1/2 100.0 1 100.0 90.0 100.0 3/4 90.0 100.0 90.0 100.0 1/2 90.0 100.0 90.0 100.0 3/8 90.0 100.0 90.0 100.0 99.0 No. 4 90.0 97.0 90.0 No. 8 45.0 19.0 42.0 32.0 52.0 42.0 56.0 46.0 75.0 65.0 No. 16 55.0 45.0 No. 30 36.0 26.0 No. 50 30.0 20.0 No. 100 13.0 8.0 No. 200 7.0 1.0 8.0 2.0 10.0 2.0 10.0 2.0 8.0 4.0 All mix designs shall be submitted to the Department for verification and approval. * Superpave designs will be accepted through the restricted zone, pending verification and approval by the Bureau of Materials & Research. The Contractor shall submit compaction data from trial blends at the optimum asphalt content and at 0.5% below and above the optimum asphalt content. The data shall include the temperature at which the HMA was aged. 2.5.1.1 All 25 mm base course mixes shall be designed using the 50 gyration Ndesign. 2.5.2 The Design Information shall include:
should be based on estimated usage or experience.
Along with the design information, Materials & Research (M&R) requires 2 quarts of the designated asphalt binder, 4 preblended aggregate specimens for gyratory and 2 preblended aggregate specimens, suitable for AASHTO T -209 when mixed New Hampshire Department of Transportation Standard Specifications – 2016 with the appropriate asphalt, in order to verify the design. M&R will accept the mix design based on the submitted informati on meeting the mix requirements and on verification of the mix volumetrics of the submitted specimen. If the verification samples indicate voids between 3.0 and 5.5 percent, and the Voids in Mineral Aggregate (VMA) and Voids Filled with Asphalt (VFA) fall within the specified limits, then the design will be accepted. Once accepted, the approved mix design is the job mix formula (JMF). If the voids are outside the aforementioned range or the VMA or VFA are outside the specified limits, the design will be rejected. M&R may elect to verify the design again. 2.5.3 The proposed mix designs and materials shall be submitted to the Engineer a minimum of 20 working days before placement for approval. It shall be the responsibility of the Contractor to ensure all approved mix designs have been entered into the plant automation system before production begins. The Contractor will also be required to post a copy of the JMF in the DOT testing laboratory. 2.5.4 Whenever the aggregate properties change enough to negate the project’s existing design, a new design shall b e submitted. 2.5.5 If it becomes necessary to change the asphalt binder grade or the source of aggregate, a new mix design shall be developed. Up to 14 calendar days will be required to evaluate a change. Approved changes in target values will not be applied retroactively for acceptance or payment. If it becomes necessary to change the source of asphalt binder, the Contractor must submit recent quality test results from the manufacturer for the asphalt binder including a temperature viscosity curve. 2.5.6 The Contractor shall perform a single point verification of an existing project mix design at the beginning of a new construction season to determine if the design remains valid. If the design is validated, the data from the single point verification shall be submitted to the Department. If the design cannot be validated, a new design shall be developed. 2.5.7 The Bureau of Materials and Research may require the use of certain chemical additives. 2.5.8 The laboratory performing the design shall be appro ved by the Department. To obtain the Department’s approval, a laboratory must demonstrate that it is equipped, staffed, and managed so as to be able to produce job mix formulas and test h ot asphalt mix in accordance with these Specifications. Approval for each laboratory shall remain in effect for a period of one year.
2.6Method Requirements.
2.6.1 Stockpiled coarse aggregate shall meet the requirements of Table 401-2. Table 401-2 -- Percent Passing
Sieve Size Base Mix 1-1/2” Binder Mix 3/4” Wearing Mix 1/2” Wearing Mix 3/8” 1-1/2” 100 1-1/4” 90.0 - 100 1” 50.0 - 85.0 100 3/4” 10.0 - 50.0 90.0 - 100 100 1/2” 15.0 - 55.0 90.0 - 100 100 3/8” 20.0 - 60.0 95.0 - 100 # 4 22.0- 55.0 No. 8 0 - 5.0 0 - 5.0 0 - 10.0 0 - 10.0 2.6.2 After the job mix formula (JMF) is established, all mixtures furnished for the project shall conform within the following ranges of tolerances: Passing No. 4 and larger sieves ±7.0 percent Passing No. 8 No. 100 sieves (inclusive) ±4.0 percent Passing No. 200 sieve ±1.0 percent Asphalt binder ±0.4 percent Temperature of mixture ± 20 °F (11 °C)
2.6.3 When Non-compliant test results, or other conditions make it necessary, it shall be the responsibility of the Contractor to make all adjustments required to ensure the mix conforms to the JMF.
New Hampshire Department of Transportation Standard Specifications – 2016 If two consecutive non -compliant results occur, the Engineer may stop production until satisfactory corrective action has been taken. A 5% reduction in unit price will be assessed to all tonnage represented by consecutive gradation failures and a 10% reduction will be assessed to all tonnage represented by consecutive asphalt binder content failures. At the Engineer's discretion, the Contractor may be required to remove non-compliant material (no payment will be made for this material or its removal). Contractor quality control personnel will not be required to be on site during production of non-quality control projects, but contract information shall be posted in the testing lab.
2.7Performance Requirements (QC/QA).
2.7.1 After any new changed job mix formula is established, all mixtures furnished for the project shall conform thereto, within the gradation and asphalt binder content reject limits in Table 401-6 in 3.17.3.1.1. Specification limits for pay adjustments under Performance Requirements (QC/QA) provisions shall be as set forth in Table 401-5 in 3.17.3.1.1. 2.7.2 The general composition limits given in Table 411-1 indicate target value ranges of mixtures permissible under Section 411. The job mix formula shall lie within the target value ranges indicated for the particular type of hot asphalt mix.
2.8General - Bridge pavement base course shall be 3/8” wearing course.
2.9General - Non-modified asphalt binder shall contain silicone additive with the concentration being 3 parts per million plus
or minus 1 part per million of silicone to asphalt binder, unless otherwise directed. Silicone additive shall be in liquid form and have a viscosity of 1,000 centipoises (1 Pas) at 77 ºF. Asphalt binder containing silicone shall meet the requirements of 401.2.2
2.10Allowed Recycled Materials – General.
2.10.1 Reclaimed asphalt pavement (RAP) may be used in the production of hot mix asphalt. The allowed dust to asphalt ratio shall be as identified in AASHTO M 323. The maximum allowable total reused “ asphalt” binder (TRB) in HMA mixes shall be 1.5%. Any changes in the combination of recycled materials shall require a new mix design unless otherwise approved by the Bureau of Materials & Research. 2.10.2 Reclaimed Asphalt Pavement (RAP). RAP shall consist of recycled asphalt pavement and shall be processed by crushing, cold milling, or other approved sizing techniques approved by the Bureau of Materials and Research to meet the required gradation specifications. The mixture of RAP and new aggregate shall meet the requirements specified in Table 401-1 for aggregate gradation. The RAP shall be tested every 1,000 tons for gradation and asphalt binder content as a stockpile is being built. These test results shall remain on file b y the Contactor until such time as the entire RAP stockpile has been utilized. 2.10.2.1 The PG grade of added asphalt shall be as specified by the Bureau of Materials and Research. The aggregate component of the RAP shall meet the requirements of 401.2.1. The bitumen component of the RAP shall be asphalt cement and shall be free of significant contents of solvents, tars, and other volatile organic compounds or foreign substances that will make the RAP unacceptable for recycling as determined by the Bureau of Materials and Research. 2.10.2.2 RAP materials may be rejected if deemed unsuitable for any reason or require an increase or decrease in the mix asphalt content. The Contractor shall submit representative samples, and gradation and asphalt cement content test results of the RAP to be incorporated into the Recycled Mixture for approval by the Bureau of Materials and Research at least 30 calendar days prior to the start of paving. 2.10.3 For all designs containing TRB in an amount greater than 1% of the total mix:
determine the appropriate grade of virgin binder to be added.
2.11Asphalt Modifiers.
General. The generic type o f each asphalt binder admixture, modifier and/or additive shall be identified on the certificate of analysis, which shall be furnished by the manufacturer for each load of asphalt delivered. Modifiers shall be pre-blended with the asphalt binder. New Hampshire Department of Transportation Standard Specifications – 2016 2.11.1 Asphalt binder modification to produce high-strength mix shall utilize either a styrene-butadiene or styrene-butadiene- styrene polymer to achieve the specified performance grade of asphalt. The Section 401 contract Special Provision specifying the asphalt binder grade shall also identify the AASHTO test method by which the binder grade shall be determined. The modified binder shall be pre-blended, storage-stable and homogeneous. 2.11.2 The use of Warm Mix Technologies is permitted in mix production. Qualified technologies are listed on the Qualified Warm Mix Asphalt (WMA) Technologies List.
2.12Pavement Joint Adhesive.
Pavement Joint Adhesive shall be a product that is listed on the Qualified Products List. 2.12.1 Joint adhesive shall meet the following requirements:
Requirements for Pavement Joint Adhesive Property Test Method Requirement Cone Penetration, 25ºC ASTM D 5329 60 -100 Flow, 60ºC ASTM D 5329 5 mm maximum Resilience, 25ºC ASTM D 5329 30% minimum Ductility, 4ºC ASTM D 113 30 cm minimum Tensile Adhesion, 25ºC ASTM D 5329 500% minimum Softening Point ASTM D 36 77ºC minimum Asphalt Compatibility ASTM D 5329 Pass
Construction Requirements
3.1Mixing Plants.
3.1.1 General. • Coarse aggregates shall be furnished in at least two nominal sizes for mix types containing top size aggregates of 1/2” and larger. • RAP shall be fed into the plant by equipment specifically designed for recycling and approved by the Bureau of Materials and Research. In addition, all requirements pertaining to aggregates shall apply to RAP. Scalping screens, grizzlies, or similar devices shall be installed on the RAP feed bin(s) to remove any debris or other foreign materials in excess of 2 ”. If a drum mix plant is used, the RAP shall be fed into the drum so that it will not come in direct contact with the burner flame. Mixing of RAP with the new aggregate shall occur before the bituminous material introduction point. The final mix produced shall be visually free from any chunks of RAP. • Plants shall be approved at least five days prior to operations and will be capable of maintaining an adequate supply of mixture to the project. 3.1.2 Method Requirements. • The site shall have ample storage space for th e required separate bins, stalls, or stockpiles to allow delivery of uncontaminated sized aggregates to the feeder. To prevent spillage from one pile or bin to the next, aggregate assigned to different stockpiles shall be separated by bulkheads or other satisfactory means. • Stockpiles of coarse aggregate produced for use in drum mix plants having top size aggregates greater than 3/4” shall be constructed in layers not to exceed 4 ft. • All blending of aggregates shall be accomplished through separate bins at the cold elevator feeders and not in stockpiles. • The plant shall be provided with a dust collector or collectors, designed to waste or return uniformly to the hot elevator all or part of the material collected, as directed. All plants shall have adequat e covers and housing as may be necessary to ensure the proper collection of dust and the general cleanliness of the plant operation. The Contractor shall comply with all State and Federal environmental regulations.
New Hampshire Department of Transportation Standard Specifications – 2016 3.1.3 Performance Requirements (QC/QA). Mixing plants shall conform to AASHTO M 156. 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. 3.1.4 Safety Requirements for Inspection – General. 3.1.4.1 Adequate and safe stairways to the mixer platform shall be provided, and guarded ladders to other plant units shall be located where required for accessibility to plant operations. 3.1.4.2 All gears, pulleys, chains, sprockets, and other dangerous moving parts shall be thoroughly guarded and protected. 3.1.4.3 Ample and unobstructed space shall be provided on the mixing platform. The plant operator shall have a clear and unobstructed view of the plant operations. 3.1.4.4 A platform shall be located in close proximity to the inspector’s laboratory for the purpose of easily obtaining samples of the mixture from the trucks. 3.1.4.5 When the plant is to be operated in other than daylight hours, adequate lighting shall be provided in all areas frequented by the inspector during his normal routine. Specific areas to be illuminated include the truck loading zone and sampling location. A light or lights shall also be located so as to allow the clear observance of the truck body lubrication operation. 3.1.5 Scheduling Inspection Personnel - General. 3.1.5.1 The Contractor shall notify the Bureau of Materials and Research at least three working days in advance of starting paving operations to allow sufficient time to schedule required plant inspection personnel. When paving bridge decks that have barrier membranes, this notice shall include the name of the membrane product so that the mix temperature may be established. 3.1.6 Access to Production Facilities – General. 3.1.6.1 The Engineer shall have access at any time to all parts of the plant for inspection of the conditions and operations of the plant, for confirmation of the adequacy of the equipment in use, for verification of proportions and character of materials, and for determination of temperatures being maintained in the preparation of the mixtures. The Contractors shall provide a suitable building, room, or trailer for exclusive use by the DOT Technician as a testing laboratory in which to house and use the testing equipment. Laboratories shall be in an approved location, with one laboratory provided for each plant. 3.1.7 Field Laboratories – General. 3.1.7.1 Field laboratories shall meet the following minimum requirements: Outside Dimensions: Method Requirements: 16 ft long by 8 ft wide [or equal] by 7 ft high (4.8 m long by 2.4 m wide by 2.1 m high). Performance Requirements (QC/QA): Laboratory shall consist of a minimum of 200 ft2 of floor space, laid out to accommodate shelves, benches, desk, equipment and personnel moveme nt. Windows: Two, with locks and screens, providing cross ventilation. Doors: One, with lock and screen. Electrical: Adequate lighting and power outlets. Air Conditioner: Unit size shall be as recommended for size of the facility. Heat: Thermostatically controlled to maintain a minimum temperature of 68°F (20°C). Weatherproofing: Roof, sides, and floor shall be maintained weatherproof at all times. Appurtenances: a) An exhaust fan and hood over the extractor. The hood shall be large enough to cover the extractor. The fan shall be a high-volume axial-flow fan, at least 10” in diameter, and of sufficient capacity to vent the fumes adequately.
formulas. Method Requirements: Suitable shelves and benches. One bench shall be approximately 24 ” wide X 36” high and at least 10 ft long. The bench may extend the length of the building.) Performance Requirements (QC/QA):Suitable shelves and benches. Bench space shall be approximately 24” wide by 36” high. There shall be a minimum total length of 19 ft of bench space.
3.1.7.2 The following office furnishings and testing equipment shall be provided:
New Hampshire Department of Transportation Standard Specifications – 2016
one each of the following sizes: 1- 1/2”, 1-1/4”, 1”, 3/4”, 1/2", 3/8”, No. 4, No. 8, No. 16, No. 30, No. 50, No. 100, No. 200, with pan and cover.
turntable, tilt to 45 degree angle and have hammers to tap each sieve during operation.
non-toxic solvent approved by the Bureau of Materials and Research.
Internet access having a minimum data rate of 256K bps.
*All ovens other than microwaves shall be vented to the outside. 3.1.7.3 All of the foregoing testing equipment shall be in good condition and shall be replaced or repaired by the Contractor if, during the duration of the project, it becomes unsuitable for testing purposes. Testing equipment shall be calibrated by the Contractor in accordance with 106.03. The above mentioned equipment is for operation of a single plant.
3.2Storage of Asphalt Binder – General.
3.2.1 Tanks for storage of asphalt binder shall be of minimum 10,000 gal capacity and equipped for heating the material under effective and positive control at all times, to the tem perature requirements set forth in the specifications for the paving mixture. Heating shall be accomplished by steam or oil coils, electricity, or other means such that no flame shall come in contact with the heating tank. 3.2.2 A complete system providin g for continuous circulation of the asphalt binder between the storage tank and the proportioning units shall be employed. The discharge end of the circulating pipe shall be maintained below the surface of th e asphalt binder in the storage tank to prevent discharging the hot asphalt binder into the open air. 3.2.3 The Contractor shall provide in the asphalt binder feed lines connecting the plant storage tanks to the asphalt binder weighting system or spray bar a sampling outlet consisting of a valve installed in such a manner that samples may be withdrawn from the line slowly at any time during plant operation. The sampling outlet shall be installed between the pump and the ret urn discharge line in such a location that it is readily accessible and free fro m obstruction. A drainage receptacle shall be provided for flushing the outlet prior to sampling.
3.3Control of Asphalt Binder – General.
3.3.1 Satisfactory means either by weighing or metering shall be provided to obtain the proper amount of bituminous material in the mix within the tolerance specified. Means shall be provided for checking the quantity or rate of flow of bituminous material into the mixer as follows:
delivered. The section of the asphalt binder flow line between the charging valve and the spray bar shall be provided with a three-way valve and outlet whereby the quantity delivered by the meter may be checked by actual weig ht. The valve controlling the flow of asphalt binder to the mixer shall close tightly to prevent asphalt binder from
New Hampshire Department of Transportation Standard Specifications – 2016 leaking into the pug mill during the mixing cycle. The meter shall be constructed so that it may be locked at any dial setting to 0.1 gal and will automatically reset to this reading after the addition of asphalt binder to each batch. The dial shall be in full view of the mixer operator. The size and spacing of the spray bar openings shall provide a uniform application of asphalt binder the full length of the mixer in a thin uniform sheet or in multiple sprays.
amount required for a batch in a single weighing. The filling system and bucket shall be of such design, size, and shape that asphalt binder will not overflow, splash, or spill outside the confines of the bucket during filling and weighing. The filling system and bucket shall be so arranged as to deliver the asphalt binder in a thin uniform sheet or in multiple sprays over the full length of the mixer. The time required to add the asphalt binder shall be not more than 15 seconds.
scales shall be equipped with a tare beam or adequate counter -balance for balancing the bucket and compensating periodically for the accumulation of asphalt binder on the bucket. 3.3.2 Suitable means shall be provided, either by steam or oil jacketing or insulation, for maintaining the specified temperatures of the asphalt binder in the pipelines, meters, weigh buckets, spray bars, and other containers or flow line.
3.4Batching Plants – General.
3.4.1 All aggregate shall be delivered by belt driven feeders. All feeders shall provide for adjustment of the cold feed and shall be capable of being secured in any position. 3.4.2 Dryers shall continuously agitate the aggregate during the heating and drying process without leaving any visible unburned oily residue on the aggregate when it is discharged from the dryer. If unusually wet aggregate is being used, the input to the dryer shall be reduced to that amount which the dryer is capable of drying. Aggregates shall be free from coatings of dust after drying. 3.4.3 Plant screens shall be constructed and operated in such manner that all aggregates will be uniformly separated into the sizes required for proportioning. They shall have sufficient capacity to furnish the necessary quantity of each aggregate size required for continuous operation. Screen cloth that has become broken or has worn sufficiently to affect the gradation shal l be replaced. 3.4.4 Thermometric equipment shall be provided as follows:
the discharge at the mixer unit.
instrument that continuously indicates the temperature of the heated aggregate at the discharge chute of the dryer. 3.4.5 Hot bins shall consist of at least four separate aggregate compartments. One compartment shall be reserved for fine aggregate, and when required, one additional compartment shall be added for dry storage of mineral filler. Alternate bin systems may be utilized with prior approval from the Department. Provision shall be made for accurate proportioning. Each compartment shall contain the following features:
other bins or into contact with the screen. Overflow apparatus shall be equipped with a telltale device that alerts the operator and the inspector when the overflow equipment is full.
3.4.6 Weigh boxes shall be of sufficient size to hold the maximum required weight of aggregate for one batch without hand raking or running over. The weigh box shall be supported on fulcrums and knife edges so constructed that they remain in alignment or adjustment. All parts of the weigh box shall be free from contact with any supporting rods, columns, or other equipment that affects the proper functioning of the hopper or scale. Gates on both bins and weigh hopper shall be constructed to prevent leakage when closed. 3.4.7 Aggregate scales for any weigh box or hopper shall be of standard make and design a nd shall be accurate to 0.5 percent of the indicated load. The weight shall be indicated on a digital display. Scales shall be substantially constructed and shall be installed in such a manner as to be free from vibration. The display shall be in full view of the operator, and the numerals shall be of such a size that they can be easily read by the inspector. If the digital display is so located that it is not easily accessible New Hampshire Department of Transportation Standard Specifications – 2016 to the inspector, a duplicate display will be required for exclusive viewing by the inspector. The job mix formula target weights shall continuously be part of the digital display during plant operations. The digital scale weight indications shall be dis played adjacent (in juxtaposition) to each target weight for easy comparison to the job mix formula. It shall be the responsibility of the Contractor to ensure that all scales are tested and sealed according to provisions as shown in the National Institute of Standards and Technology Handbook 44, at least on an annual basis. The work shall be accomplished by a competent commercial scale company prior to the start of the construction season. Scales shall be re -tested prior to use, after they have been moved. The Contractor shall have readily available at least ten standard 50 lb weights, for checking the scales during operations. 3.4.8 The batch mixer shall be of an approved pug mill type, hot oil or steam jacketed, or heated by other approved means and capable of producing uniform mixtures within the specified tolerances. The m ixer shall have a batch capacity of not less than 4,000 lb and be constructed so as to prevent leakage during the mixing cycle. The amount of material that may be mixed per batch shall not exceed the manufacturer's rated capacity. If the mixer does not m ix properly at the rated capacity, or if its production does not coordinate with the other plant units, the Department reserves the right to reduce the size of the batch until the desired efficiency is obtained. The pug mill shall be equipped with a sufficient number of paddles operated at such speed as to produce a properly and uniformly mixed batch. If, in the course of mixing, two adjacent paddle tips become broken, immediate repair will be called for. If the paddle tips become broken at widely separated points, repair may be delayed until the end of the working day. The clearance of the tips from all fixed and moving parts shall not exceed 3/4”. Badly worn or defective tips shall not be used in mixing operations. The mixer shall be covered to preve nt loss of fine material. The discharge gate shall be so designed that no uncoated material is retained at the gate opening during the mixing operation. Leakage from the pug mill gate during operation will not be permitted. 3.4.9 Each plant shall be equi pped with an accurate time lock to control the operations of a complete mixing cycle. A mixing cycle shall consist of two periods, the dry mixing period and the wet mixing period. The dry mixing period shall be t he interval of time between the opening of the aggregate weigh hopper gate and the start of the application of asphalt binder. The wet mixing period shall be the interval of time between the start of the application of asphalt binder and the opening of the mixer gate. The time lock shall be capable of being set at intervals of five seconds or less throughout the mixing cycle and shall have a suitable case equipped with an approved lock. The setting of time intervals shall be performed in the presence and under t he direction of the Engineer who may lock the case until such time as a change is to be made in timing periods. The time lock shall lock the asphalt binder bucket throughout the dry mixing period and shall lock the mixer gate throughout the dry and wet mixing period. 3.4.10 The use of a fully automatic batching plant will be required and shall meet the following requirements:
components of the mixture by weight in the specified sequence and for controlling and timing the mixing operation. Interlocks shall be provided that delay, stop, or lock out the automatic batch cycling whenever the batched quantity of any component weight or the total batch is not within the specified weight tolerance, or when there is a malfunction in any portion of the control system.
cycle in the underweight check position and in the overweight check position for each material so that the tolerance setting may be checked.
so that the dial can be moved smoothly and sl owly through its range to check the settings of the automatic control system. The plant operator shall perform this automatic control system checkout procedure periodically as requested by the Engineer.
Component Weighed Percentage of Total Batch Weight Tare weight of aggregate weigh box ±0.5 Tare weight of asphalt binder weigh bucket ±0.1 Each aggregate component ±1.5 Mineral filler ±0.5 Asphalt ±0.1
include an automatic printer system. The printer shall be positioned so that the scale reading and the printer can be readily observed from one location by the plant inspector. The printer shall produce, in digital form, a weight slip conforming to the requirements of 109.01 and 401.3.8.1.
New Hampshire Department of Transportation Standard Specifications – 2016
to operate. 3.4.11 The aggregate shall be dried and heated to a minimum temperature of 260° F. The asphalt binder shall be heated to a temperature between 260º and 325º F. Each size of hot aggregate, the mineral filler if required, and the bituminous cement sh all be measured separately and accurately to the proportions in which they are to be mixed. The mixture shall be made by charging the mixer with the hot aggregate, coarse sizes first, unless otherwise directed, which shall be dry mixed for 5 to 15 seconds. The asphalt binder shall be added and the mixing continued until a uniform coating is obtained and all particles of the aggregate are thoroughly coated. The total dry and wet cycle shall not be less than 35 seconds for base and binder mixtures and not less th an 40 seconds for the wearing course. In no case shall the total mixing period exceed 75 seconds. 3.4.12 If the aggregate in the hot bins contains sufficient moisture to cause foaming in the mixture, such aggregate shall be removed from the bins, and production rate shall be reduced so as not to exceed the capacity of the dryer. Material having once gone through the mixing plant shall not be returned to the stockpiles.
3.5Drum Mix Plants – General.
3.5.1 The plant shall be specifically designed for the process and shall be capable of satisfactorily heating, drying, and uniformly mixing the bituminous material and aggregate in accordance with the job mix formula. The rate of flow through the drum shall be controlled in order that a homogeneous mixture is obtained with all particles uni formly coated. In no case shall the quantity of mix produced exceed the manufacturer’s rated capacity. If the percent of moisture in the mixture exceeds 1.0 percent by weight, the right is reserved to decrease the rate of production. The plant shall be equipped with automatic burner controls. 3.5.2 The cold bins shall be divided in at least five compartments and shall be designed to prevent the overflow of material from one bin to another. When reclaimed pavement is used, an additional bin designed for this purpose will be required. In event of an emergency this bin may be used to feed aggregate in an amount not to exceed 15% of material to complete the days production. Each cold bin shall be equipped with an orifice to feed the aggregate accurately and uniformly. The feeding orifice shall be adjustable, and indicators shall be provided to show the gate opening. An automatic plant shutoff device shall be provided to operate when any aggregate bin becomes empty or the flow from any bin gate becomes restricted. A vibrator or other suitable means may be required in order to ensure a uniform flow of materials. The order of aggregate feed onto the composite cold feed belt shall be from coarse to fine. 3.5.3 The total cold aggregate feed shall be weighed continuously by an approved belt scale. The weighing system shall register within +0.5 percent of the indicated load. 3.5.4 Proportioning controls for aggregate and asphalt binder shall be located at the panel that also controls the mixture and the temperature. The panel shall be equipped with automatic controls that shall display, in digital form, the percentages of asphalt binder, mineral filler if required, and each aggregate in the job mix formula. The panel shall also be equipped to raise and lower the production rate without having to reset the individual controls for each change in production rate. The controls shall maintain aggregate flow accuracy such that the total variation of all materials being drawn per interval of time shall not exceed an amount equal to 1.5 percent of the total weight of bituminous mixture per interval of time. 3.5.5 Provisions shall be made for introducing the moisture content of the total cold feed into the belt weighing system and correcting the wet aggregate weight t o dry aggregate weight. The system shall be capable of adjusting the flow of bituminous material to compensate for any variation in the dry weight of the aggregate flow. It shall be the responsibility of the Contractor to monitor and determine accurate mo isture contents of the aggregate and RAP stockpiles used for production of hot mixed asphalt. Accurate moisture contents shall be determined at a minimum every other day of production. In the event of rain, moisture contents shall be determined for all aggregates and RAP to be utilized before the next day’s production. 3.5.6 The dry weight of the aggregate flow shall be displayed by automatic digital readout in units of weight per interval of time. 3.5.7 When mineral filler is specified, a separate bin and feeder shall be provided with a variable drive interlocked with the aggregate feeders. Mineral filler shall be introduced and uniformly dispersed into the mixture without loss to the dust collection system. A device shall be provided to indicate when the flow of filler into the delivery system stops or its specified volume is out of job mix tolerance. The rate of flow shall be accurate to within 0.5 percent by weight, of the total mix. Means shall be provided to readily divert the flow of mineral filler into a container for measurement. 3.5.8 The asphalt binder shall be introduced through a continuously registering cumulative indicating meter by a pump specifically designed for the plant. The meter shall be located in the asphalt line so that it continuously registers the asphalt discharge to the mixer and so that the discharge through the meter can be readily diverted into a suitable container for New Hampshire Department of Transportation Standard Specifications – 2016 measurement by actual weight. The meter shall indicate accurately to within 1.0 percent the amount of asphalt binder being delivered. The accuracy of the pump and meter shall be verified at periodic intervals as designated by the Engineer. 3.5.9 Satisfactory means shall be provided to ensure positive interlock between dry weight of aggregate flow and the flow of bituminous material through an approved meter. 3.5.10 The flow of bituminous material shall be displayed by automatic digital readouts in terms of volume or intervals of weight and time. 3.5.11 The plant shall have a means of diverting mixes at start up and shut down or where mixing is not complete or uniform. 3.5.12 A surge or storage system complying with 3.7 shall be provided.
3.6Mixing Temperature.
3.6.1 Method Requirements. 3.6.1.1 The Engineer may adjust the job mix formula temperature withi n the limits of 260° and 350°F according to the existing conditions. Material with a temperature at discharge outside the job mix formula tolerance may be rejected. In no case will a mixture be accepted with a discharge temperature in excess of 375°F. 3.6.1.2 During hot weather, the temperature of the mixture when discharged shall be as low as is consistent with proper mixing and placing. During cold weather, a temperature approaching the upper limit is desirable 3.6.2 Performance Requirements (QC/QA). 3.6.2.1 The job mix formula temperature may be adjusted within the limits of 260 °F and 350 °F according to the existing conditions. Material with a temperature at discharge outside the job mix formula tolerance may be rejected. In no case will a mixture be accepted with a discharge temperature in excess of 375 °F.
3.7Hot Storage System – General.
3.7.1 Material may be placed in a storage silo for a period not to exceed 24 hours from the time of mixing. The upper and lower gates when closed shall create an airtight seal. The silo shall be filled to capacity. 24 hour storage will not be allowed if there is reason to believe there is a problem with the gate seals or excessive heat loss. 3.7.2 The hot storage system shall be capable of conveying the hot m ix from the plant to insulated and enclosed storage bins and storing the hot mix without appreciable loss in temperature, asphalt migration, segregation, or oxidation. 3.7.3 The conveyer system may be a continuous type or skip bucket type. If the continuous type is used, it shall be enclosed to prevent a drop in mix temperature. If the skip bucket type is used, the bucket must be of sufficient capacity to transpor t an entire batch and mass dump it into the bins. 3.7.4 The storage bins shall be designed in such a manner as to prevent segregation of the hot mix during discharge from the conveyor into the bins and shall be equipped with discharge gates that do not cause segregation of the hot mix while loading the mix into the trucks. The storage bin heating system shall be capable of maintaining the mix temperature without localized heating (hot spots). 3.7.5 The bin shall be equipped with a light or indicator to show when the level of material reaches the top of the discharge cone. The bin shall not be emp tied below the top of the discharge cone until the use of the bin is completed each day. The material remaining in the discharge cone may be rejected if there is evidence of segregation.
3.8Weighing and Hauling – General.
3.8.1 The Contractor shall provide an approved automatic printer system that prints the weights of the material delivered, provided the system is used in conjunction with an approved automatic batching and mixing control system. Such weights shall be evidenced by a weight slip for each load. 3.8.2 Weight slips shall include requirements as shown in 109.01 and the following for batch plants with automatic proportioning equipment:
New Hampshire Department of Transportation Standard Specifications – 2016 3.8.3 Each weight slip will show a consecutive load number and shall include an accumulative total of material delivered for each day.
3.9Vehicles – General.
3.9.1 The inside surfaces of vehicles may be lightly lubricated with a soap solution or non -petroleum release agent that will not be detrimental to the mix . Equipment that leaks oil, diesel fuel, gasoline, or any other substance detrimental to the pavement will not be allowed on the project. 3.9.2 The mixture shall be transported from the paving plant to the project in trucks having tight, smooth, metal beds previously cleaned of all foreign materials. Truck beds may be lined with a polyethylene type material designed and installed for hauling hot bituminous mixes. Each load shall be covered with canvas or other suitable material of sufficient size and thickness to retain heat and to protect it from weather conditions. The cover material when new shall weigh a minimum of 18 oz/yd2 and it shall be a tightly woven or solid material. When necessary, so that the mixture can be delivered on the project at the specified temperature, truck beds shall be insulated, and covers shall be securely fastened.
3.10Placing – General.
3.10.1 Prior to placing of any mix, a pre-paving conference shall be held to discuss and approve the paving schedule, source of mix, type and amount of equipment to be used, sequence of paving pattern, rate of mix supply, traffic control, and general continuity of the operation. Special attention shall be made to the paving pattern sequence to minimize cold joints. The field supervisors of the above mentioned operations shall attend this meeting. 3.10.2 The Contractor shall notify the Engineer at least five working days in advance of paving operations to allow sufficient time to schedule required site inspection and testing. All paving and c ompaction equipment shall be approved and on site prior to start up each day. 3.10.3 Crack sealing material to be covered by a 1 ” or less overlay shall cure a minimum of 45 days prior to the placement of bituminous pavement. 3.10.4 Base course pavement lifts shall not exceed the maximum compacted thickness of 5 inches. Any course exceeding 5 compacted inches shall be placed in 2 passes. 3.10.5 When performing paving operations at night, in addition to the requirements of 3.1.4.5, the Contractor shall provi de sufficient lighting at the work site to ensure the same degree of accuracy in workmanship and conditions regarding safety as would be obtained in daylight. 3.10.6 Performance Requirements (QC/QA). The Contractor shall provide the following equipment for testing and sampling at the project site. The equipment shall be in good condition and shall be replaced by the Contractor if, during the duration of the project, it becomes unsuitable for testing or sampling purposes. 3.10.6.1 Metal plate 12 ” minimum each side, flat bottom scoop 3000- gram capacity minimum, and sample containers to perform NHDOT B-7 sampling. 3.10.7 Weather Limitations. 3.10.7.1 General. In special instances, when the Engineer determines that it is in the best interest of the State, the Engineer may waive the requirements of 3.10.7, provided that 3.10.7.3 shall always remain in effect. 3.10.7.2 Any material delivered to the spreader having a temperature lower than 260 o F shall not be used unless modified by a qualified warm mix technolog y capable of being compacted to project requirements at the recommended delivery temperature. 3.10.7.3 Mixtures shall be placed only when the underlying surface is dry and frost free. The Engineer may permit, in case of sudden rain, the placing of mixture then in transit from the plant, if laid on a base free from pools of water, provided motorist visibility is not impaired and all other specifications are met. No load shall be sent out so late in the day that spreading and compaction cannot be completed du ring the daylight, unless the requirements of 3.10.5 are met. The Engineer may suspend operations for the day when the Contractor is unable to meet specifications. 3.10.7.4 All mix placed after October 1st and before May 1st shall be modified by a qualified warm mix technology. 3.10.7.4.1 Wearing course shall not be scheduled for placement after October 1st and before May 1 st without written approval by the Engineer. 3.10.8 At the beginning and end of the project or project section, the existing pavement shall be removed to a sufficient depth to allow the placing of the new pavement and construction of a transverse joint, which shall be painted with a suitable bituminous New Hampshire Department of Transportation Standard Specifications – 2016 material. The underlying course shall be clean and free from foreign materials and loose bituminous patches and must present a dry, unyielding surface. 3.10.9 Sweeping - General. Existing pavement or previously laid courses shall be thoroughly dry and free from all dust, dirt, and loose material. Sweeping with a power broom, supplemented by hand brooming, may be necessary. 3.10.10 Tack coat - General. Surfaces of any pavement course shall have a tack coat of emulsified asphalt applied in accordance with the requirements of 410.3.4. 3.10.10.1 Tack will be sampled daily and tested by NHDOT for conformance with Section 410. Any pavement that has been placed over tack that is found to be out of specification, but is deemed suitable to remain in place by t he Engineer, will be subject to a 3% price reduction. The price reduction will be applied only to the pavement placed on the date that the tack is sampled. This price reduction will not relieve the Contractor of responsibility for latent defects and/or gross mistakes as outlined in section 107.14. 3.10.11 General - Drainage and utility structures within the limits of the pavement shall be set and raised in accordance with the provisions of 604.3.4. Contact surfaces of the drainage and utility castings as ordered shall be painted with a thin coating of suitable bituminous material.
3.11Pavers.
3.11.1.1 Pavers shall be:
within 18” of the end plate for fixed-width paving.
lane.
of the screed.
shoving, or gouging the mixture.
providing the automatic signals that operate the screed to maintain grade and transverse slope from a reference such as a grade wire or ski type device, either a floating beam with a minimum length of 30 ft or sonic averaging with a minimum length of 24 ft. 3.11.1.2 Material Transfer Vehicle (MTV). An approved MTV shall be used to transfer the bituminous mix from the hauling equipment to the paver. The MTV shall operate independently from the paver and shall be a commercially manufactured unit specifically designed for the transfer of mix from the hauling equipment to the paver without depositing the mix on the roadway. It shall have the ability to swing the discharge conveyor to reach the paver hopper. The MTV shall be designed so that the mix is internally remixed. The minimum storage capacity of the MTV shall be 12 tons. The MTV will only be required for mainline construction and straight ramps (does not include loop ramps, interim connections, interim crossovers and side roads) when the section is a minimum of 600 tons per paver mobilization unless otherwise approved by the Contract Administrator. When the MTV passes over a bridge that is not a fill over structure it shall be as near to empty a s possible. The MTV also shall not exceed 5 miles per hour while on the bridge. If the Contractor proposes moving the MTV over a bridge with more than a minimal amount of material in it, a proposal must be submitted to and approved by the Bureau of Bridg e Design prior to the placing of any mix. The submittal needs to show in detail the wheel and axle loading that will be placed on the bridge deck. 3.11.1.3 When patching existing pavement, the material shall be placed on the prepared clean underlying surf ace at the locations designated and shall be spread to produce a smooth and uniform patch. The patch material shall be thoroughly compacted and shall match the line and grade of the adjacent pavement. 3.11.1.4 Relatively small areas not accessible to the paver may be spread by hand, but extreme care shall be taken to create a surface texture similar to the machine work. Surface material shall be spread by lutes and not by rakes. 3.11.1.5 Unless otherwise authorized, the final wearing course shall not be p laced until guardrail posts have been set and general cleanup has been completed.
New Hampshire Department of Transportation Standard Specifications – 2016 3.11.1.6 When hot bituminous bridge pavement is to be placed over barrier membrane, the placing temperature shall be as specified in 538.3.3.5. A paver, mounted on rubber tracks or tires, shall be used to place the 1” base course unless this procedure is found to cause damage to the membrane. When such damage is found to be evident, the hand method may be allowed. The hand method may also be allowed if the Engineer determines that the use of a paver for this work is impracticable. During warm weather, the above paving shall be done during the cool period of the day. A paver shall be used to place the wearing course. 3.11.1.7 Where pavement is placed adjacent to structural members such as expansion joints, the material in the top course shall be placed so that the compacted grade of the pavement is 1/4 to 3/8 ” above the grade of the structural member. 3.11.1.8 When paving on aggregat e base courses and/or base course pavement, the first pass paved shall be on the travel way and on the shoulders. 3.11.1.9 Pavers used for all 403.11 _____ Item work shall have a minimum weight of 28,000 lbs. and a minimum 8 -foot wheelbase. 3.11.2 Method Requirements 3.11.2.1 All courses shall be spread and finished to the required thickness by approved, self -contained, self -propelled spreading and finishing machines (pavers). Pavers shall be provided with an adjustable, activated screed and shall be capable of spreading the mixtures with a finish that is smooth, true to the required cross -section, uniform in density and texture, and free from hollows, tears, gouges, corrugations, and other irregularities. Broadcasting behind the paver shall be held to a m inimum. Pavers shall be capable of spreading and finishing courses of the required thicknesses and lane widths. Horizontally oscillating strike-off assemblies will not be approved. 3.11.2.2 The activated screed shall be of the vibrating or tamping bar type or a combination of both and shall operate without tearing, shoving, or gouging the mixture. The activated portion of the screed shall extend the full width of the mixture bei ng placed in the traveled way and other areas with sufficient width to accommodate a paver. In other locations as permitted such as narrow shoulders, tapers, and areas adjacent to curbs, non-activated extensions to the screed will be allowed. The paver shall be equipped with a screed heater. The screed heater shall be used when starting a cold machine and for maintaining a suitable screed temperature when needed. 3.11.2.3 Blaw Knox Pavers shall be equipped with the manufacturer’s material management kit. The paving Contractor shall certify that this work has been done before using any Blaw Knox paver. 3.11.2.4 The paver hopper gates shall be adjusted to pass the correct amount of mix to the spreading screws so that the screws operate more or less continuously. The height of material shall be maintained at a constant level in front of the screed, to a point where approximately half of the auger shall be visible at all times. 3.11.2.5 When required by the Engineer pavers shall be equipped with the following automatic screed controls for each paver:
The sensors for either or both sides of the paver shall be capable of sensing grade from an outside reference line or from the surface using a ski type device and shall be capable of sensing transverse slope of the screed. The sensors shall provide automatic signals that operate the screed to maintain the desired grade and transverse slope. Pavers shall not be used until the autom atic controls have been checked and approved by the Engineer. 3.11.2.6 The use of automatic grade and slope controls shall be required on all pavers. 3.11.2.7 Whenever a breakdown or malfunction of the automatic controls occurs, the equipment may be operated manually for the remainder of the normal working day on which the breakdown or malfunction occurred. This method of operation must meet all other specifications. 3.11.2.8 On projects or parts of projects where the Engineer deems that the use of automatic con trols are impracticable, some or all of the controls listed in 3.11.1.5 may be waived. 3.11.2.9 The forward speed of the paver shall be adjusted to the rate of the supply of materials so that the paver operates without having to make stops except for emergencies. If the Engineer determines that the paving operations result in excessive stopping of the paver, the Engineer may suspend all paving operations until the Contractor makes arrangements to synchronize the rate of paving with the rate of delivery of materials. New Hampshire Department of Transportation Standard Specifications – 2016 3.11.3 Blank.
3.12Compaction.
3.12.1 General. Unless an alternate compaction package is approved at the project pre- pave meeting, roller trains shall consist of the equipment describe herein. 3.12.2 Method Requirements. 3.12.2.1 Immediately after the hot asphalt mix has been spread, struck off, and surface irregularities adjusted, it shall be thoroughly and uniformly compacted by rolling. The initial rolling shall be done with a static or vibratory steel -drum roller. Intermediate rolling shall be done by a pneumatic-tired roller. Final rolling shall be done with a static steel-drum roller or a roller of the steel-drum three-axle type, locked. The completed course shall be free from ridges, ruts, humps, depressions, objectionable marks, visible segregation, or irregularities and in conformance with the line, grade, and cross -section shown in the Plans or as established by the Engineer. Rollers must be in good mechanical condition, free from excessive backlash, faulty steering mechanism, or worn parts. The empty weight and the ballasted weight shall be properly marked on each roller. The minimum weight of static steel-drum rollers shall be 8 tons. When a vibratory roller is being used, the vibration shall stop automatically when the roller is stopped or reversing direction of travel. 3.12.2.2 Pneumatic-tire rollers shall be self -propelled and shall be equipped with smooth tires of equal size and diameter. The wheels shall be so spaced that one pass of a two -axle roller accomplishes one compl ete coverage. The wheels shall not wobble and shall be equipped with pads that keep the tires wet. The rollers shall provide an operating weight of not less th an 2,000 lb per wheel. Tires shall be maintained at a uniform pressure between 55 and 90 psi w ith a 5 psi tolerance between all tires. A suitable tire pressure gauge shall be readily available. 3.12.2.3 Unless otherwise directed, rolling shall begin at the sides and proceed longitudinally parallel to the roadway center line, gradually progressing to the crown of the roadway. The overlap shall be one-half the roller width for wheeled rollers and 6 in for vibrating rollers. No overlap is required for pneumatic -tired rollers. When paving in echelon or abutting a previously placed lane, the longitud inal joint shall be rolled first followed by the regular rolling procedure. On superelevated curves, the rolling shall begin at the low side and progress to the high side by overlapping of longitudinal passes parallel to the cente rline. 3.12.2.4 Rollers shall move at a slow but uniform speed with the drive roll or drive wheels nearest the paver, except on steep grades. Static and pneumatic-tired rollers shall not operate at speeds in excess of 6 mph. All courses shall be rolled until all roller marks are eliminated. Cores shall be collected by the Contractor at locations as determined and witnessed by the Engineer. One core per lane mile, but no less than two, shall be taken for each roadway segment paved. When shoulders are overlayed, cores shall be coll ected solely for density information at a frequency of one core for every 750 tons of mix. The Contractor will deliver the cores to the designated testing laboratory once NHDOT chain of custody measures have been applied. The minimum compaction requiremen t shall be 91% of maximum theoretical density as determined in accordance with AASHTO T 209. The following reductions in unit price shall apply for all tonnage placed that is represented by any core (excluding shoulder cores) that does not meet the minimum requirement: for results below 91% but equal to or greater than 90%, a 5% reduction will be assessed; for any results below 90%, a 10% penalty for all tonnage placed will be assessed. At the Engineer's discretion, the Contractor may be required to remove noncompliant material below 90% (no payment will be made for this material or its removal). 3.12.2.4.1 All cores need not be cut at the same time. The Contractor is allowed the option to collect cores through all placed lifts at once, provided cores are collected within two working days of placing the first course. Corrective action to any covered course is at the Contractor’s risk. 3.12.2.5 Any displacement occurring as a result of reversing the direction of a roller, or from other causes, shall be corrected at once by the use of lutes and the addition of fresh mixture when required. Care shall be exercised in rolling so as not to displace the line and grade of the edges of the bituminous mixture. 3.12.2.6 To prevent adhesion of the mixture to the rolle rs, the wheels shall be kept properly moistened with water or water mixed with very small quantities of detergent or other approved material. Excess liquid will not be permitted. All steel ro llers shall be equipped with adjustable wheel scrapers. 3.12.2.7 Along forms, curbs, headers, and similar structures and other places not accessible to a normal full -sized roller, sidewalk rollers weighing at least 2,000 lb (900 kg) shall be used. Where rollers are impracticable, the mixture shall be thoroughly compacted with heated or lightly oiled hand tamps or vibrating plate compactors.
New Hampshire Department of Transportation Standard Specifications – 2016 3.12.2.8 Unless the Engineer determines that for the weight and placement conditions a lesser number will be satisfactory to obtain the desired pavement densities, the following is the list of required compaction equipment. The output of each paver placing wearing course (Table 1) materials shall be compacted by the use of one each of the following complement of rollers as a minimum: a static or vibratory steel-wheel roller, a pneumatic-tired roller and a three-axle roller or a static steel-wheeled roller. If the required density is not being obtained with the rollers supplied, the use of additional rollers of the specified type may be ordered. Paving widths in excess of 16 ft (5 m) will require additional rollers as ordered. 3.12.3 Performance Requirements (QC/QA). 3.12.3.1 Immediately after the hot asphalt mix has been spread, struck off, and surface irregularities adjusted, it shall be thoroughly and uniformly compacted. The co mpleted course shall be free from ridges, ruts, humps, depressions, objectionable marks, visible segregation, or irregularities and in conformance with the line, grade, and cross -section shown in the Plans or as established by the Engineer. If necessary, the mix design may be altered to achieve desired results. 3.12.3.2 All compaction units shall be operated at the speed, within manufacturers recommended limits, that will produce the required compaction. The use of equipment, which results in excessive crushing of the aggregate will not be permitted. Any asphalt pavement that becomes loose, broken, contaminated, shows an excess or deficiency of asphalt binder, or is in any way defective, shall be removed and replaced at no additional cost with fresh hot asphalt mix, which shall be immediately compacted to conform with the surrounding area. Hot asphalt mix shall not be permitted to adhere to the roller drums during rolling. 3.12.3.3 The type of rollers to be used and their relative position in the compaction sequence shall be the Contractor's option, provided specification densities are attained and with the following stipulations:
or cracking of the mat occurs, when fracturing of aggregate occurs, and on bridge decks.
3.13Joints - General.
3.13.1 Unless otherwise shown on the plans, the longitudinal wearing course joints shall be at the edge of lane placed, where the edge line, lane line and centerline pavement markings will be applied, and joints of other courses shall be offset approximately 6”. 3.13.2 The material being placed next to a previously paved lane shall be tightly crowded against the face of the abutting lane. The paver shall be positioned so that during spreading, the material will overlap the edge of the first lane by 1 to 2 ” and shall be left sufficiently high such that finish pavement of the lane being placed is approximately 1/8” higher than the previously paved lane after compaction. The overlapped material shall be rolled without luting. Longitudinal joint compaction shall be achieved by rolling from the hot side to within 6 ” of the previously placed mat. The next roller pass will over lap onto the previously placed paved lane by 6 ” Further compactive effort shall be applied to all joints during the intermediate and final rolling. 3.13.3 Placing of the course shall be as continuous as possible while complying with Contract Traffic Contr ol Plans. Transverse joints will be allowed at the end of each work shift or as required to provide properly bonded longitudinal joints . 3.13.3.1 No longitudinal joints greater than 1-1/2” height shall be left open to traffic unless a tapered overlapping (“wedge”) joint is used. Centerline joints greater than 3/4” shall be properly delineated by tubular marker and signed appropriately. Joints between traveled way and shoulder greater than 3/4 ” shall be delineated by barrels. Tubular markers and barrels shall meet the requirements of Section 619. Tubular markers shall be secured to the pavement. 3.13.3.2 Unless otherwise precluded by weather conditions, longitudinal joints shall not remain open to traffic longer than 30 hours. 3.13.4 If a bulkhead is not used to form the transverse joint, the previously laid material shall be cut back to the designed slope and grade of the course. The joint face shall be coated with approved bituminous bonding material meeting the requirements of 410.2.1 before the fresh mixture is placed against it. Extreme care shall be taken to ensure that no unevenness occurs at the joint. If unsatisfactory riding qualities are obtained at the transverse joint in the w earing course, the joint shall be corrected by an approved method. 3.13.4.1 Prior to opening any lane(s) to traffic, transverse joints shall be ramped by means of an asphalt fillet at a minimum of 5 ft. horizontal to 1” vertical slope. 3.13.4.2 When paving into a permanent transverse joint, a full head of material shall be carried into the joint. New Hampshire Department of Transportation Standard Specifications – 2016 3.13.5 When specified, a bituminous pavement joint adhesive, Item 403.6, shall be applied to the longitudinal joint. If joint adhesive has not been specified, an approved bituminous bonding material meeting the requirements of 410.2.1 shall be applied to completely cover all joint contact surfaces. 3.13.5.1 Joint adhesive shall be applied to the longitudinal joints so that the entire j oint surface is covered with a minimum 1/8” thick layer of material. If a wedge joint is used the upper 4” of joint surface shall be covered with joint adhesive. In lieu of using joint adhesive, the Contractor may elect, with the approval of the Engineer, to use multiple pavers in echelon to eliminate the longitudinal joint. Echelon paving shall be performed as stated in 3.13.8. 3.13.5.2 The joint face on which the joint adhesive is to be applied shall be dry, free from loose material, dust, or other debris that could interfere with adhesion. If dust or debris adheres to the joint adhesive, it shall be cleaned or recoated as directed by the Engineer. 3.13.5.3 Trucks or traffic shall not drive across the joint adhesive until it has cooled sufficiently to prevent damage from tracking. 3.13.5.4 Joint adhesive shall be melted in a melting kettle that meets the requirements of 413.2.2(b) . The joint adhesive shall be applied at the temperature specified by the manufacturer and shall not be heated above the safe heating temperature specified by the manufacturer. 3.13.5.5 Joint adhesive shall be applied using a pressure feed wand applicator system equipped with an applicator shoe as recommended by the manufacturer. A pour-pot applicator will be allowed on wedge joints only. 3.13.5.6 Joint adhesive (Bridge Base) shall be applied to curbs, concrete armoring, and pavement matches so that the entire joint is covered with a minimum 1/8” thick layer of material. 3.13.6 A tapered overlapping (“ wedge” ) joint may be used on all longitudinal joints provided that the adjacent lane can be placed when the existing surface temperature is above 50° F. 3.13.6.1 An inclined face (3:1) on the joint shall be formed in the first bituminous mat placed. The inclined face may be for the entire height or an inclined face with a 1/2” maximum vertical face at the top of the mat. 3.13.6.2 After the initial mat is placed, the mat shall be rolled to the edge of the unconfined face. 3.13.6.3 When the adjoining mat is placed the initial longitudinal wedge shall be treated as in 3.13.5. 3.13.6.4 The joint matching and compaction shall be performed in accordance with 401.3.13. 3.13.7 The Contractor shall furnish and have available a 10 ft, light -weight metal straightedge with a rectangular cross - section of 2 by 4” at the paver at all times during paving operations. All courses shall be tested with the straightedge laid across the transverse joint parallel to the centerline and any variations from a true profile exceeding 3/16 ” shall be satisfactorily eliminated. The finished surface of the pavement shall be uniform in appearance, shall be free from irregularities in contour, and shall present a smooth-riding surface. 3.13.8 Echelon Paving. Echelon paving, when specified or approved, shall be defined as multiple pavers paving simultaneously and adjacent to one another such that all rolling of both mats is performed concurrently.
3.14Variations in Profile and Cross Slope – Method (See 3.17.3.4.1).
3.15Replacement – General. If unsatisfactory areas are found in any course, the Contractor shall remove the unsatisfactory
material and replace it with satisfactory material.
3.16Finished Appearance – General. Any bituminous material remaining on exposed surfaces of curbs, sidewalks, or other
structures shall be removed.
3.17Additional Performance Requirements (QC/QA).
3.17.1 Quality Control. 3.17.1.1 The Contractor shall operate in accordance with a Quality Control Plan , hereinafter referred to as the “ Plan”, sufficient to assure a product meeting the Contract requirements. The plan shall meet the requirements of 106.03.1 and these special provisions. 3.17.1.2 The Plan shall address all elements which affect the quality of the Plant Mix Pavement including, but not limited to, the following:
New Hampshire Department of Transportation Standard Specifications – 2016
pressure for pneumatic tired rollers.
minor approaches, to ensure a proper finish and drainage.
3.17.1.3 The Plan shall include the following personnel performing the described functions and meeting the following minimum requirements and qualifications:
Degree in Civil Engineering Technology or Construction.
of aggregates and other mix components and control proportioning to meet the job mix formula(s). The PCT shall periodically inspect all equipment used in mixing to assure it is operating properly and that mixing conforms to the mix design(s) and other Contract requirements. The Plan shall detail how these duties and responsibilities are to be accomplished and documented and whether more than one PCT is required. The Plan shall include the criteria utilized by the PCT to correct or reject unsatisfactory materials. The PCT shall be certified as a Plant Technician by the New England States Technician Certification Program or be a Materials Testing Technician in Training, working under the direct observation of a NETTCP certified Plant Technician.
delivered materials meet the requirements of the job mix formula(s). The QCT shall inspect all equipment utilized in transporting, laydown, and compacting to assure it is operating properly and that all laydown and compaction conform to the Contract requirements. The pla n shall detail how these duties and responsibilities are to be accomplished and documented, and whether more than one QCT is required. The Plan shall include the criteria utilized by the QCT to correct or reject unsatisfactory materials. The QCT shall be certified as a HMA Paving Technician as certified by the North East Transportation Training and Certification Program or be a Materials Testing Technician in Training, working under the direct observation of a NETTCP certified HMA Paving Technician. 3.17.1.4 The Plan shall detail the coordination of the activities of the Plan Administrator, the PCT and the QCT. The Plan shall also detail who has the responsibility to reject material, halt production or stop placement. 3.17.1.4.1 All issues agreed to at the Pre-Paving meeting shall be considered to be part of the Plan. 3.17.1.5 Asphalt pavement shall be sampled, tested, evaluated and recorded by the Contractor in accordance with the minimum process control guidelines in Table 401-3. 3.17.1.5.1 Cross slope shall be measured on every pavement lift using t he method described in 3.17.3.5.1 prior to placement of subsequent lifts. Particular emphasis on the first pavement lift shall be required when correcting existing substandard cross slopes. Cross slope measurements exceeding 0.5% from the specified cross slope for that location shall require an adjustment in ongoing or subsequent paving operations to correct the deficiency. If two or more consecutive measured sublots are greater than 0.5% from the specified cross slope, paving operations shall cease until the Contractor submits a corrective action satisfactory to the Engineer.
New Hampshire Department of Transportation Standard Specifications – 2016 Table 401-3 - Minimum Process Control Guidelines Properties Test Frequency Test Method Temperature of Mix 6 per day at paver hopper and plant Surface Temperature As needed Temperature of Mat 4 per day Density 1 per 500 tons (500 metric tons) or minimum 2 per day AASHTO T 343 or ASTM D 2950 Maximum Theoretical Specific Gravity 1 per day of operation AASHTO T-209 Fractured Faces 1 per 2000 tons (1800 metric tons) for Gravel Sources only AASHTO T 11 & AASHTO T 27 Aggregate Gradation & Asphalt Binder content 1 per 750 tons (700 metric tons) recommended AASHTO T 130 & 164 Asphalt Binder As needed AASHTO M 226 M 320 Thickness Contractor Defined Contractor Defined Cross Slope 1 per 5 full stations Per 3.17.3.5.1
3.17.1.6 Rejection by Contractor . The Contractor may, prior to sampling, e lect to remove any defective material and replace it with new material at no expense to the Department. 3.17.1.6.1 No wearing course pavement shall be removed or repaired without prior approval of the Engineer. 3.17.1.7 The Contractor may utilize innovative eq uipment or techniques not addressed by the specifications or these provisions to produce or monitor the production of the mix, subject to approval by the Engineer. 3.17.2 Quality Assurance. 3.17.2.1 Asphalt pavement designated for acceptance under Quality Assurance (QA) provisions will be sampled once per sublot on a statistically random basis, tested, and evaluated by the Department in accordance with 106.03.2 and the acceptance testing schedule in Table 401 -4. Testing shall not take place until the material has been placed and deemed acceptable by the Contractor. Table 401-4 - Acceptance Testing Schedule PROPERTIES POINT OF SAMPLING LOT SIZE SUBLOT SIZE TEST METHOD Gradation Behind paver & before rolling(4)
401.3.17.2.2 750 tons AASHTO T 30 NHDOT B-1 Asphalt Binder content Behind paver & before rolling(4)
401.3.17.2.2 750 tons AASHTO T 164 NHDOT B-2 NHDOT B-6 Maximum theoretical specific gravity Compacted Roadway(1) Core 750 tons NHDOT B-8 AASHTO T 209 In Place Air Voids in total mix(5,6,7) Compacted roadway(1) core
401.3.17.2.2 750 tons NHDOT B-8 AASHTO T 269 Ride Smoothness(7) Completion of wearing surface Total project 0.1 lane mile 401.3.17.3.4 Cross Slope(7) Completion of wearing surface Total project 1 per 5 full stations 401.3.17.3.5 Thickness(2)(5) (7) Compacted roadway(1) core Total project 750 tons NHDOT B-8 ASTM D 3549
New Hampshire Department of Transportation Standard Specifications – 2016
running total of tonnage supplied to each paver on each paver.
3.17.2.2 Lot Size. For purposes of evaluating all acceptance test properties a lot shall consist of the total quantity represented by each item listed under the lot size heading in the table above, up to 15,000 tons. For Items with quantities in excess of 15,000 tons, lot sizes will be determined at the pre-placement meeting. Each lot will be broken down into at least 3 sublots. The Contractor may request a change in the job mix formula. If the request is approved, all of the material produced prior to the change will be evaluated on the basis of available tests and a new lot will begin. Three sublots must be sampled and tested before a new lot may begin. 3.17.2.2.1 A lot for Gradation, Asphalt Content and In Place Air Voids shall be the total quantity represented by the job mix formula with the following exception; the shoulders will be evaluated as a separate lot for in place air voids. 3.17.2.3 Sublot Size. The quantity represented by each sample will constitute a sublot. The size of each sublot shall be as listed under the sublot size heading in Table 401 -4. If there is insufficient quantity in a lot to ma ke up at least three sublots of the designated size in Table 401-4, then the lot quantity will be divided into three equal sublots. If there is less than one half of a sublot remaining at the end, then it shall be combined with the previous sublot. If the re is more than one half sublot remaining at the end, then it shall constitute the last sublot and shall be represented by test res ults. 3.17.2.4 Test Results. The Engineer may calculate pay factors and pay adjustments at any time while a lot is being produced. This may be necessary for a partial estimate or to see if quality is falling to a point where immediate attention is required. Pay factors will be determined from all available acceptance tests for the lot being evaluated. 3.17.3 Acceptance Testing 3.17.3.1 Gradation and Asphalt Binder Content. Samples for gradation and asphalt binder content shall be obtained from behind the paver in conformance with NHDOT procedure B -7 (see appendix A) and taken from each pavement layer by the Contractor in the presence of the Engineer. The sample locations will be established by selecting a random location within each sublot in accordance with Section 106. Sample locations (center of sample) will not be within 1 foot from an edge of pavement or within 4 feet from any structure. Sample locations falling within 4 feet from any structure will be relocated 4 feet fr om the structure along station at the same offset. Where samples have been taken, new material shall be placed and compacted to conform to the surrounding area immediately after the samples are taken. Samples shall be accompanied by a sample tag containing the following information:
When the project exceeds 30 minutes travel time from the testing laboratory location, material samples will be taken and identified by NHDOT project personnel and shall be transported before cooling by the Contractor and delivered to NHDOT testing technicians at the testing laboratory location. Samples lost in transit will incur a penalty of 5% of the bid price for the entire sublot represented by that sample. Sublots with no test results due to a lost sample will not be evaluated and the total quantity represented by that sublot shall not be included in any positive pay factor. 3.17.3.1.1 Testing. Target values shall be as specified in the job mix formula. All sieve sizes specified in the job mix formula will be evaluated for gradation. The specification limits in Table 401 -5 will be used for calculating pay factors for gradation and asphalt binder content. New Hampshire Department of Transportation Standard Specifications – 2016 Table 401-5 - Gradation and Asphalt Binder Specification Limits Property Maximum Aggregate Size 1” 3/4” 1/2” 3/8” USL and LSL (Target +/- %) 1 1/2” 0 1-1/4” 8.0 1” 8.0 0 3/4” 7.0 5.0 0 1/2” 7.0 5.0 4.0 0 3/8” 7.0 5.0 4.0 4.0 No. 4 4.0 4.0 3.0 4.0 No. 8 4.0 4.0 3.0 3.0 No. 16 2.0 2.0 2.0 2.0 No. 30 2.0 2.0 2.0 2.0 No. 50 2.0 2.0 2.0 2.0 No. 100 2.0 2.0 2.0 2.0 No. 200 0.8 0.8 0.8 0.8 Asphalt Binder 0.4 0.4 0.4 0.4 Any sublot with a gradation or asphalt binder content falling outside the ranges of the reject limits in Table 401-6 will be either removed and replaced at the expense of the Contractor or require corrective action to the satisfaction of the Engineer. After replacement or correction, new samples will be taken and the old test results from that sublot will be disc arded. Table 401-6 - Gradation and Asphalt Binder Content Reject Limits (Deviation from Target)
SIEVE SIZE 1” 3/4” 1/2” 3/8” Percent Passing By Weight – Combined Aggregate 1-1/4” 1” 3/4” ±12 (1) 1/2” (1) ±10 (1) 3/8” (1) (1) ±10 (1) No. 4 ±9 ±9 ±9 ±9 No. 8 ±7 ±7 ±7 ±7 No. 16 ±6 ±6 ±6 ±6 No. 30 (1) (1) (1) (1) No. 50 (1) (1) (1) (1) No. 100 (1) (1) (1) (1) No. 200 ±3 ±3 ±3 ±3 Asphalt Binder: % of Mix ±1.0 ±1.0 ±0.8 ±0.8
The Contractor shall have the option of requesting a change in job mix formula (aim change) values used for calculating quality level to reflect actual production values after the placement of two sublots as long as no change in plant production values are made. A new lot is not needed for this change. 3.17.3.2 In Place Air Voids. In place air voids shall be determined in accordance with AASHTO T 269 using 6 ” diameter cores taken from each pavement layer by the Contractor in the presence of the Engineer. Core sampling shall be in conformance with ASTM D 5361 and NHDOT B-8 (see Appendix A). Full depth cores containing all new pavement layers shall be required. Core locations (center of core) will be established by selecting a random location wit hin each sublot in accordance with Section 106. When shoulders are overlayed, cores shall be collected solely for density information at a frequen cy of one core for every 750 tons of mix. Cores will not be located in the following areas:
New Hampshire Department of Transportation Standard Specifications – 2016
structure along station at the same offset.
Cores shall be taken before opening pavement to traffic, except when location of core is within the last hour of that day’s placement. Cores shall be taken within 24 hours after placement. W here cores have been taken, new material shall be placed and compacted to conform to the surrounding area the same day the samples are taken. Core samples shall be accompanied by a sample tag containing the following information:
The complete sample(s) (unseparated) shall be protected against damage, transported and delivered by the Contractor within one working day to NHDOT testing technicians at the testing lab location. Sublots where the core becomes lost or damaged will be resampled at the direction of the Engineer at the Contractor’s expense.
The specification limits in Table 401-7 will be used for calculating pay factors for in place air voids for each lot: Table 401-7 - In Place Air Voids Acceptance Limits TARGET (%) LSL USL Average of Samples - 2.0%1 +2.0%2 1 But not less than 2.5% 2 But not more than 9% When a core is less than 80% of the nominal thickness, a new core will be taken in the same sublot at a random location for the determination of in place air voids. A sublot with a test result less than 2.0% for in place air voids will be rejected and sub ject to removal and replacement. 3.17.3.2.1 Maximum Theoretical Density (MTD). MTD shall be determined in conformance with AASHTO T 209 once per sublot from the core obtained for determining in place air voids. 3.17.3.2.2 Disputed Cores. If a Contractor believes that a core result is invalid for whatever reason, the Contractor shall notify the Engineer of this in writing within 24 hrs. of being informed of the test result. After being informed of the disputed core result, the Engineer will select three random core locations, one in each three sections of the disputed sublot at the same offset as the disputed core. The Contractor shall cut the cores at the selected locations in the presence of the Engineer who shall place them in secured containers for delivery and testing at the Bureau of Materials and Research laboratory in Concord, NH. If there are 10 or more cores already tested to date, the pay factor for voids in the lot will be calculated (without using the result of the disputed core). If less than ten cores have been tested in the disputed lot, the three cores shall be held until ten cores have been tested or the lot is complete, whichever comes first, at which time the pay factor will be calculated. If the pay factor for the lot that contains the d isputed result is 0.95 or greater, and the disputed test result is outside three standard deviations from the mean value of the lot (calculated without using the result of the disputed core), the three cores shall be tested and the average value of the three will be calculated. If any of these three cores falls outside three standard deviations from the mean value for the lot (calculated without using the result of the disputed core), the original core test value will stand. If the three cores fall within three standard deviations of the mean value the average of the three cores will be used as the core result for the disputed sublot. If the three cores are not used, the Contractor shall pay for the cost of testing. 3.17.3.3 Pavement Thickness. The thickness requirements contained herein shall apply only when each pavement layer is specified to be a uniform thickness greater than 3/4 ” The thickness of each layer of hot asphalt mix will be measured in New Hampshire Department of Transportation Standard Specifications – 2016 conformance to ASTM D 3549 to determine compliance with the acceptance tolerance. Measurements shall be obtained from cores taken for determining in place air voids of each pavement layer. A leveling course, or the first layer over a gravel or stone base, a milled surface or an existing surface, shall be excluded from thickness measurement. 3.17.3.3.1 Once each thickness measurement has been taken, a thickness index will be calculated. The thickness index is the actual deviation from target divided by the allowable tolerance. This will allow statistical comparisons to be made among measurements based on varying specified thickness. Thickness indexes will be established for the sole purpose of calculating pay factors. Thickness index shall be calculated under the following equation using the specification limits in Table 401 -8. TI = (M - ST)/T
where: TI = Thickness Index ST = Specified Thickness M = Measured Layer Thickness From Core T = 15% x ST, but no less than 1/4” Table 401-8 -Thickness Index Acceptance Limits TARGET LSL USL Thickness Index 0.00 -1.00 +1.00
3.17.3.3.2 Disputed Thickness If a Contractor believes that a thickness result is invalid for whatever reason, the Contractor shall notify the Engineer of this in writing within 24 hrs of being informed of the test result. A fter being informed of the disputed result, the Engineer will select three random core locations in the disputed sublot and the Contractor shall cut the cores at the selected locations in the presence of the Engineer who shall place them in secured containers for delivery and testing at the Bureau of Materials and Research laboratory in Concord, NH and deliver them to the testing technician. If there are 10 or more cores already tested to date, the pay factor for thickness in the lot will be calculated (without using the result of the disputed core). If less than ten cores have been tested in the disputed lot, the three cores shall be held until ten cores have been tested or the lot is complete, whichever comes first, at which time the pay factor will be ca lculated. If the pay factor for the lot that contains the disputed result is 0.95 or greater, and the disputed test result is outside three standard deviations from the mean value of the lot (calculated without using the result of the disputed thickness), the three cores shall be measured and the average value of the three will be calculated. If any of these three cores falls outside three standard deviations from the mean value for the lot (calculated without using the result of the disputed core), the original thickness test value will stand. If the three cores fall within three standard deviations of the mean value the average of the three measurements will be used as the thickness for the disputed sublot. If the three cores are not used, the Contractor shall pay for the cost of testing. 3.17.3.4 Ride Smoothness.
cross section of 2” x 4” at the paver at all times during paving oper ations. All courses shall be tested with the straightedge laid parallel or perpendicular to the centerline and any variations from a true profile or cross slope exceeding 3/16 ” shall be satisfactorily eliminated. The finished surface of the pavement shall be uniform in appearance, free from irregularities in contour and shall present a smooth-riding surface.
device provides a Ride Number in both wheel paths that are averaged to produce a ride number for the surface tested. In the event the Engineer feels that there is a significant difference in the wheel path profiles, a Ride Number evaluation of the individual wheel paths will be made. The surface will be tested within 30 days after the wearing surface and pavement markings for each discrete section of the project are complete. Immediately before testing, the Contractor will ensure the surface is entirely free from any foreign matter t hat may affect the test results. No special considerations will be given to criteria such as degree of curve and vertical geometry. Ride Number will be calculated to the nearest one hundredth for each 0.1 mile segment.
will begin 20 feet after the approach joint and end 20 feet before the departure joint. The pavement will not be evaluated over bridge expansion joints, tapers, raised pavement markings, and sections less than 0.1 mile in lane length.
1” of the full lane width by the length required (a minimum of 100 feet) and replaced at the Contractor's expense.
New Hampshire Department of Transportation Standard Specifications – 2016
shall not exceed 1.05 and will be computed as follows: For Level 1 Projects: (Ride Number 4.20) Pay Factor = RN (0.5)-1.1 For Level 2 Projects: (Ride Number 4.14) Pay Factor = RN (0.5682) – 1.3523
completed sections of a project will be evaluated before the entire wearing surface is completed. Any sublot with a ride number less than 3.7 shall be repaired or replaced. 3.17.3.4.6.1 Any sublot that has an individual wheel path ride number less than 3.7 shall be r epaired or replaced. The repair treatment shall be for the full width of the lane. Sublots that have been repaired or replaced shall be reevaluated f or ride smoothness and then averaged with all other sublots to determine the final project pay factor. Construction joints resulting from repairs or replacement will be included.
3.17.3.5.1 Cross slope will be measured once per sublot (see Table 401-4) behind the paver after final rolling of the wearing surface has taken place. Cross slope will only be evaluated when specific slopes and superelevations are shown on th e plans for the entire project. Only travel lanes will be evaluated for cross slope. Measuremen ts will be taken only in areas of normal tangent or full bank curves on even stations. Measurement shall take place utilizing one of the following methods, and shall be agreed upon by both parties: “digital read” level and 10 to 12 foot straightedge; “bu bble” level, ruler, and 10 to 12 foot straightedge; transit; or electronic positioning equipment as approved by both Contractor and Department. If a straightedge is employed, perpendicularity shall be assured with the use of a right angle prism or other m ethod acceptable to both parties. If a “bubble” or “digital read” level is employed, a second reading 180 degrees to the first shall be made and recorded, and the t wo shall be averaged for the test result. Measurement data shall be shared between parties within 24 hours of measurement. 3.17.3.5.2 Once a cross slope percentage has been measured, a cross slope index (CSI) will be calculated. The target cross slope shall be defined as the cross slope shown on the plans or as ordered to the nearest tenth of a percent. The CSI is the actual deviation from the target divided by 0. 40 percent, which is the tolerance used for pay factor calculation only . This will allow statistical comparisons to be made among measurements based on varying specified cross slopes . The CSI will be established for the sole purpose of calculating pay factors. The CSI shall be calculated under the following equation using the specification limits in Table 401-10. CSI = T SCSM )( −
where: CSI = Cross Slope Index SCS = Specified Cross Slope in percent M = Measured Cross Slope in percent T = 0.40 Table 401-10 - Acceptable Quality Level Limits TARGET LSL USL Cross Slope Index 0.00 -1.00 +1.00 New Hampshire Department of Transportation Standard Specifications – 2016 3.17.3.5.3 If three or more consecutive cross slope subl ot measurements on the pavement lift used to calculate the pay factor deviate more than 0.5 (in percent) from the specified cross slope value at those locations, those sublots will be considered to exceed the engineering limit of 0.5% . The Contractor shal l submit a corrective action plan for approval by the Engineer for cross slope sublots that exceed this limit. 3.17.3.5.4 After the approved corrective action plan is implemented, the sublots will be measured to ensure compliance, but will not be re -measured for the purpose of re -calculating pay factor. Alternatively, the Contractor may submit a written request for acceptance of the material at a negotiated price. The Engineer will determine whether the material may remain in place at the negotiated price. 3.17.3.6 Rejection of Material. 3.17.3.6.1 An individual sublot. For any sublots with any test results exceeding the specified reject limits, the Engineer will:
additional expense to the department, or
3.17.3.6.2 A lot in progress. The Engineer will shut down paving operations whenever:
sieve have at least one fractured face. Paving operations shall not resume until the Engineer determines that material meeting the Contract requirements can be produced. Corrective action will be considered acceptable by the Engineer if the pay factor for the failing property increases. If it is determined that the resumption of production involves a significant change to the production process, the current lot w ill be terminated and a new lot will begin. 3.17.3.6.3 Remeasure and Retest. All requests to the Engineer to remeasure and retest a sublot shall be in writing. Method of Measurement
4.1Asphalt pavement mixture will be measured by the ton to the nearest 0.1 ton, and in accordance with 109.01. Batch weights
will be permitted as a method of measurement only when the provisions of 3.8.3 are met, in which case, payment will be based on the cumulative weight of all the batches. The quantity will be the weight used in the accepted pavement, and no deduction will be made for the weight of asphalt binder or additives in the mixture. 4.1.1 Hot bituminous pavement, machine or hand method (night) will be measured in the same manner as 4.1. No separate measurement will be made for lighting necessary or overtime required due to night operations at the plant or at the site. 4.1.2 Due to possible variations in the specific gravity of the aggregates, and to possible field changes in areas to be paved, the quantity used may vary from the proposal quantities, and no adjustment in Contract unit price will be made because of such variations.
4.2Asphalt pavement, removed because of faulty workmanship or contamination by foreign materials, will not be included in
the pay quantity.
4.3Blank.
4.4Joint adhesive will be measured by the linear foot for each lift of pavement to be placed, to the nearest foot of adhesive
applied. If the Contractor chooses to pave in echelon in lieu of using joint adhesive, payment for the length of joint eliminated by the echelon paving will be made.
4.5Echelon paving, when specified or approved, will be measured by the linear foot along the shared edge of the mats being
simultaneously placed. Basis of Payment
5.1All work performed and measured as prescribed above will be paid for at the Contract unit price as provided in the respective
sections for each type specified.
5.2Tack coat material ordered under 3.10.10 will be paid as provided for in Section 410.
5.3Blank.
New Hampshire Department of Transportation Standard Specifications – 2016
5.4Plant or project site lighting for hot bituminous pavement, machine or hand method (night), or overtime required due to
night operations will be subsidiary to the paving items.
5.5Asphalt cement additives will be subsidiary to the paving items.
5.6Implementation of the Quality Control Plan and costs associated with obtaining core samples for acceptance testing shall
be subsidiary. When ite ms are to be accepted under Quality Assurance provisions, pay adjustment will be made in accordance with 106.03.2.4 as specified below. 5.6.1 Gradation composite pay factor (CPF). The total price for each lot w ill be adjusted by a composite pay factor
factors in Tables 401-11, 11a & 11b. Table 401-11 - Sieve Size Weight Factors 1” Property Weight Factor “ f” 1/2” 6 #30 4 Gradation (each sieve) #8 and #200 sieves 8 All other sieves (each) 2
Table 401-11a - Sieve Size Weight Factors 3/4” Property Weight Factor “ f” 3/8” 6 #30 4 Gradation (each sieve) #8, and #200sieves 8 All other sieves (each) 2
Table 401-11b - Sieve Size Weight Factors 1/2” and 3/8” Property Weight Factor “ f” No. 4 6 #30 4 Gradation (each sieve) #8, and #200 sieves 8 All other sieves (each) 2
Composite Pay Factor (CPF) = [ ( ) ( ) ... ( )]f PF f PF f PF f j j1 1 2 2+ + Σ
5.6.2 Pay Adjustment. The pay adjustment for each measured characteristic will be determined by the following equation: ))(()1( PQf fPfPA j jj ∑ −= where: PA = Pay adjustment payment in dollars for each characteristic. Pf = Pay factor or composite pay factor for each characteristic. f = Weight factor from Table 401-12 for each characteristic. f∑ = Sum of weight factors. Q = Quantity computed from all accepted delivery records for the lot. P = Contract unit price per ton. New Hampshire Department of Transportation Standard Specifications – 2016 Table 401-12 – Tier 1 Weight Factors Measured Characteristic Weight Factor “ f” Gradation 0.15 Asphalt Binder Content 0.15 In Place Air Voids 0.20 Thickness 0.08 Cross Slope 0.12 Ride Smoothness 0.30
Table 401-13 – Tier 2 Weight Factors Measured Characteristic Weight Factor “ f” Gradation 0.25 Asphalt Binder Content 0.25 In Place Air Voids 0.5
5.6.3 Pay adjustment, Hot Bituminous Pavement QC/QA Items. The pay adjustment for gradation, cross slope, thickness, asphalt binder content, in place air voids, and ride quality (made up of the sum of all sublots) will be applied to item
1010.3Pay adjustments may be applied at the end of each month based on all available test results for each lot
5.7The accepted quantity of joint adhesive of type specified will be paid for at the Contract unit price per linear foot complete
in place. 5.7.1 Recoating of the joint, as described in 3.13.5, shall be at the Contractor’s expense. 5.7.2 When echelon paving is used in lieu of joint adhesive and the item is not included in the contract, the accepted quantity will be paid for at the price of joint adhesive under Item 403.65.
5.8The Material Transfer Vehicle (MTV) Item will be paid for at the Item Bid Price per ton for the tons of bituminous mixture
actually transferred by the MTV.
5.9The accepted quantity of echelon paving will be paid for at the Contract unit price per linear foot complete.
5.9.1 If the Contractor chooses to pave in echelon in lieu of pavement joint adhesive, and the item is not in the contract, echelon paving will be paid as stated in 5.7.
New Hampshire Department of Transportation Standard Specifications – 2016 Appendix A
NHDOT Test Procedure B-7 Sampling Bituminous Paving Mixtures For Acceptance Testing Sample shall be taken behind the paver after placement and before compaction. Sample location is randomly selected by the Contract Administrator. When paving over aggregate base course or cold planed surface, use a rectangular metal plate no less than 12 ” each side. Center plate on sample location. After paver passes over plate, measure back to sample location. Locate the edges of the plate. Using a flat-bottomed scoop large enough to obtain up to a 3000 gram sample. Place scoop on plate and push across the mat (perpendicular to the center line), through the center of the plate, filling the scoop to obtain the sample size specified below. Required Sample Size Base Courses 2000-3000 grams Binder Courses 1500-3000 grams Surface Courses 1000-3000 grams Sand Courses 500-3000 grams
When sampling over an existing pavement the plate is not required. NHDOT Procedure B-8 Sampling and Testing Procedure for In Place Air Voids Cores will be taken at random locations selected by the Contract Administrator. Cores will be delivered intact by the Contractor to the NHDOT inspector at the testing laboratory. If Cores are lost or damaged, new cores shall be taken at the same location as the previous core. Cores shall be measured for thickness following ASTM D 3549. Bulk specific gravity shall be determined by AASHTO T 166a. Maximum Theoretical Density will be determined using the core by AASHTO T 209. In Place Air Voids shall be determined by AASHTO T 2.
New Hampshire Department of Transportation Standard Specifications – 2016
Description
This work shall consist of cons tructing one or more courses of bituminous pavement on a prepared base as shown on the
plans or as ordered. The methods may be classified as hand or machine. 1.1.1 Hand method shall include only the paving of ra ised islands, slopes, cattle passes, areas between rails at railroad crossings, existing sidewalks, drives, drive aprons, curb patch between concrete barrier and pavement, curb patch between granite curb and pavement, and paving of 50 tons or less added after the completion of paving operations. 1.1.2 Machine method shall include all paving not classified as hand method.
When specified this work shall consist of constructing one or more courses of hot bituminous pavement using modifier to
create higher strength.
This work shall consist of constructing bituminous pavement under nighttime operation and will be indicated in the item
description. The location shall be as shown on the plan or as ordered. Materials
Materials and their use shall conform to the requirements of 401.2.
Temporary bituminous pavement shall conform to Ta ble 401-1. Thickness shall be as shown on the plans or as ordered by
the Engineer. Construction Requirements
Construction requirements shall be as prescribed in 401.3.
For temporary pavement only, amend portions of 401.3.12 as follows:
3.2.1 The requirements of 401.3.12.2.1 shall apply except rolling may be accomplished with a dual vibrating steel drum roller. 3.2.2 Delete 401.3.12.3.
For temporary bituminous pavement only delete 401.3.13.7.
Temporary bituminous pavement shall be removed when no longer needed.
Methods of Measurement
Hot bituminous pavement will be measured as prescribed in 401.4.
4.1.1 Hot bituminous pavement, machine or hand method (night) will be measured in the same manner as 4.1. No separate measurement will be made for lighting necessary at the plant or at the site Hot Bituminous pavement transferred by the Mater ial Transfer Vehicle (MTV) will be measured as prescribed in 401.4. Basis of Payment
The accepted quantities of hot bituminous pavement will be paid for at the Item Bid Price per ton for the bituminous mixture,
complete in place. 5.1.1 The accepted quantity of hot bituminous pavement, machine or hand method (night) will be paid for at the Contract unit price per ton complete in place. 5.1.2 No separate payment will be made for any costs of plant or project lighting, or overtime for night work needed due to night operations.
Bridge wearing course will be paid under machine method.
The accepted quantity of temporary bituminous pavement will be paid for at the Contract unit price per ton complete.
5.3.1 Removal of the temporary pavement will not be paid for under other items of the Contract but will be subsidiary.
PLANT MIX PAVEMENTS – GENERAL in other states
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