The Contractor shall submit for Department approval a JMF to th e Asphalt Pavement Engineer for each mixture to be supplied. The JMF will be approved by the Department in accordance with the MaineDOT HMA P olicies and Procedures for HM A Sampling and Testing Manual. At the time of JMF submittal, the Contractor sh all identify and make available the stockpiles of all proposed aggregates at the plan t site. There must be a minimum of 150 ton for coarse aggregate stockpiles and 75 ton f or fine aggregate stockpiles before the JMF may be submitted. The Contractor shall provide aggregate samples to the Department unless otherwise required. The Contractor shallals o make available to the Department the PGAB proposed for us e in the mix in sufficient q uantity to test the properties of the asphalt and to produce samples for testing of the mixture. The first day’s production shall be monitored, and the approval may be withdraw n if the mixture exhibits undesirable characteristics such as checking, shoving or displa cement. The Contractor shall be allowed to submit aim changes for a JMF as outlined in the M aineDOT HMA Policies and Procedures for HMA Sampling and Testing Manual: Mix Design Approval Section. The Contractor shall submit a new JMF for approval each time a change in material source or materials properties is proposed. The same approval process shall be followed. The cold feed percentage of any aggregate may be adjusted up to 10 percentage points from the amount listed on the JMF, however no aggregate listed on th e JMF shall be eliminated. The cold feed percentage for RAP may be reduced up to 10 percen tage points from the amount listed on the JMF and shall not exceed the percentage of RAP approved in the JMF or for the specific application under any circumstances.
401.031 Warm Mix Technology The Contractor may place Hot Mix As phalt Pavement
produced with an accepted WMA technology if approved by the Dep artment. Methods or technologies shall generally be at the Contractors option, but will be limited to proven, Agency and Industry accepted practice. Mixture production, plac ement and volumetric testing details, including temperatures, shall be included in t he project specific QCP, and submitted to the Department for approval prior to any work.
401.04Temperature Requirements The temperature of the mixture shall conform to the
tolerances in Table 2 as measured at the truck at the mixing pl ant and at the paver unless otherwise authorized by the Department.
TABLE 2: ALLOWABLE TEMPERATURE RANGES PGAB Grade(s) Temperature Range (°F) PG58-28 / PG64-28 275-325 PG64E-28 / PG70E-28 285-335
The Contractor shall utilize either a PG58- 28, PG64-28, PG64E-28, PG70E-28, or ot her grade as specified in the 403 Special Provision. The Contractor shall utilize a PG64-28 if no liquid grade is specified within the 403 Special Provision.
401.06Weather and Seasonal Limitations The State is divided into two paving zones as
follows:
Bangor to Calais.
TABLE 3: SEASONAL AND TEMPERATURE LIMITATIONS Use Minimum Ambient Air Temperature Zone 1 Allowable Placement Dates Zone 2 Allowable Placement Dates Surface course (travelway & adjacent shoulders) less than 1 in. thick placed during conditions defined as “night work” 50°F June 1 to Saturday following September Surface course (travelway & adjacent shoulders) less than 1 in. thick 50°F May 15 to Saturday following September Travelway surface course greater than or equal to 1 in. thick 50°F May 1 to Saturday following October 1 April 15 to Saturday following October 15 HMA for surface course on bridge decks 50°F May 1 to Saturday following October 1 April 15 to Saturday following October 15 HMA for base or shim course on bridge decks 50°F April 15 to November 15 HMA for use other than travelway surface course 40°F April 15 to November 15 HMA for curb, driveways, sidewalks, islands, or other incidentals 40°F N/A N/A HMA produced with an approved WMA technology for base or shim course 35°F April 15 to November 15
The ambient air temperature shall be determined by an approved thermometer placed in the shade at the paving location. Unless otherwise specified, t he Contractor shall not place Hot Mix Asphalt Pavement on a wet or frozen surface regardless of the ambient air temperature. The Hot Mix Asphalt Pavement produced with an appr oved WMA technology shall meet the requirements of section 401.04 - Temperature Req uirements, unless otherwise approved by the Department. For the purposes of this Section, t he traveled way includes truck lanes, ramps, approach roads and auxiliary lanes.
401.07Hot Mix Asphalt Plant
1 General Requirements HMA plants shall conform to AASHT O M156,
Standard Specification for Requi rements for Mixing Plants for H ot-Mixed, Hot-Laid Bituminous Paving Mixtures with exception of Section 4.2.1, 4.2 .2, 4.3.4, 4.3.5, and 4.12.2. All HMA plants will be inspected annually by the Department pri or to producing HMA for Department projects. The Cont ractor shall provide the Depar tment at least 72 hour’s notice that the plant is ready for inspection. The HMA plant wi ll be equipped with ladders and platforms that are accessible and safe to obtain belt and b inder samples. The HMA plant
will have a sampling platform to perform HMA sampling from the back of haul units. Silo storage time of mixtures shall not exceed 36 hours.
2 Stockpiles HMA plants shall have sufficient space for stockpiles, with a
minimum of supply for 2 days production of all aggregate produc ts used in MaineDOT approved mix designs currently under production for the facilit y at all times. A minimum stockpile supply of 100 ton (70 yards) shall be maintained alwa ys no matter the production rate for the HMA plant. Stockpiles shall be separated and built to minimize segregation. All aggregate stockpiles of products used in MaineDOT approved mix designs shall be labelled with signage made of weather-proof material. Stockpile identifi cation signs shall be a minimum size of 12” high and 24” wide with reflective lettering that is a minimum of 2” in height. The sign shall be placed so that it is easily readable from outside the stockpile area.
3 Cold Feeds Cold Feed Bins will have bin dividers to k eep aggregate from
intermingling between bins. Adequate means must be provided for obtaining samples of the complete and combined flow of all Cold feed bins. Cold feed bins will not be required to have individual sampling locations.
4 Dryer Dryer shall be capable of heating aggregate to required mixing
temperature and shall be in good operation and condition. Dryer shall be subject to annual inspection prior to start-up. The Contractor shall dry and heat the aggregates for the HMA to the required temperature. The Contractor shall properly adjust flames to avoid physical damage to the aggregate and to avoid depositing soot on the agg regate. The Contractor shall provide the Department the opport unity to inspect the dryer pri or to the annual inspection. The Contractor shall provide the Department a minimum period of 72 hours to inspect the dryer and provide at least 24 hour’s notice that the dryer is r eady for inspection.
5 Asphalt Binder Asphalt binder heating system shall he at binder to proper
mixing temperature. A thermometer shall be provided in the asph alt binder line. Indirect asphalt binder heating system shall be used and no direct flame may come in contact with tank. The temperature of asphalt binder shall be uniformly main tained using insulation or another approved method. An asphalt binder sampling valve shall be provided in the circulation line. The sampling valve shall be provided downstre am of any binder additive used. The use of a different sampling location may be approved by the Department. The Contractor shall drain down the a sphalt as low as safely possible in any tank that will be switched to a new source or grade prior to adding the new PGAB.
6 Additives Additives (WMA, anti-strip, etc.) not direc tly introduced into the
binder at the terminal shall be introduced into the HMA plant p er the supplier’s recommendations and shall be approved by the Asphalt Pavement E ngineer, Pavement Quality Manager, or their authorized representative. The system for introducing additives shall be interlocked with the aggregate feed or weigh system to maintain correct proportions for all rates of production and batch sizes. Additive introduction systems shall be controlled by a proportioning device to the a mount required on the JMF plus or minus 0.1% of the target. Additive introduction systems shall be interlocked with the plant and the recordation (batch tickets or drum recordation) shall display the additive and the weight and percentage
added. A means for sampling any mixture additives will be provi ded. The sampling point shall be after the additive is mixed with the PGAB before entering the drum or mixer unit.
7 Batch Plants
Hot Bins Hot bins shall provide uniform continuous operation and be in g ood working condition. The plant shall be able to provide samples of hot bins upon req uest. Overflow shall be provided for each hot bin. Hot bin ga tes shall close withoutle aking. Bin walls must prevent intermingling between bins. Each hot bin shall have telltale de vices (“low level indicator”) which will alter the operator when the bin is empty. Mixer Unit Clearance between blades and liner shall be adjusted to 1” maxi mum, unless the aggregate exceeds 1 ¼” then the clearance shall be 1 ½”. The sp ray bar length shall be at least 75% of the mixer length. The mixer unit shall be a twin p ug mill-type mixer capable of mixing continuously for at least 45 seconds after all materials have been introduced into the mixer. The blades in the mixer shall be of sufficient number an d size, capable of producing a homogenous mixture. If the mixer is not enclosed, it shall be e quipped with an adjustable hood to prevent loss of dust by dispersion. The mixer unit shal l be subject to annual inspection prior to removal of safety features and being readie d for service. The Contractor shall provide the Department the opportunity to inspect the mix er unit prior to the annual inspection. The Contractor shall provide the Department a minim um period of 72 hours to inspect the mixer unit and provide at least 24 hour’s notice th at the mixer unit is ready for inspection. Mineral Filler Mineral filler and fiber shall utilize separate bins and feeds ystems to store and proportion the required quantity into the mixture. The feed sys tems shall be accurate to no more than 10% of the required weight with a convenient and accu rate means of calibration. Mineral filler and fiber shall be introduced in the weigh hoppe r and uniformly distributed prior to the injection of the asphalt binder. Automation The HMA batch plant shall automatically batch materials, mixes and discharges mixes. The batch plant shall accurately proportion the various materia ls in the proper order by weight. The entire batching and mixing cycle shall be continuo us and shall not require any manual operations. The batch plant shall use auxiliary interlo ck circuits to trigger an audible alarm whenever an error exceeding the acceptable tolera nce occurs. Along with the alarm, the printer shall print an asterisk on the delivery slip in the same row containing the out-of-tolerance weight. The automatic proportioning system sh all be capable of consistently delivering material within the full range of batch sizes. When RAP is being used, the plant must be capable of automatically compensating f or the moisture content of the RAP. The HMA batch plant shall be operated within the following tole rances:
Each aggregate component +/-1.5% cumulative, per bin Mineral Filler + / - 0.5% Bituminous Material + / - 0.1% Zero return (aggregate) +/- 0.5% Z e r o R e t u r n ( A C ) + / - 0.1% Additives + / - 0.1% Recordation All plants shall be equipped with an approved digital recording device. The printer shall mark any weight on the ticket that exceeds tolerance. The deliv ery slip load ticket shall contain information require d under Section 108.1.3 - Provisions Relating to Certain Measurements, Mass and paragraphs a, b, and c of Section 401.07 8.
8 Drum Plants
Cold Feeds and Delivery System A scalper screen shall be used to remove oversize material. The accuracy of the belt scale shall be within +/- 1.0% of the actual weight being meas ured. The HMA drum plant shall be capable of correcting for aggregate moisture. Mineral filler and fiber shall utilize separate bin(s) and feeder systems to store and proportion the required quantity into the mixture. The feed systems shall be accurate to no more than +/- 10% of the required weight with a convenient and accurate means of calibration. The plant shall be equipped with a single control to change all feed rates. Mineral filler and fiber shall be introduced such that dry mixing is accomplished no less than 18 inches prior to the injection of the asphalt binder. The Contractor shall ensure that the mineral filler do es not become entrained in the exhaust stream of the dryer. Binder System The flow of asphalt binder shall adjust automatically with dry aggregate weights. The Department will conduct an asphalt flow meter check annually an d after each plant change of location. The flow meter check must be performed prior to re ceiving approval to produce for Department projects. The pl ant must be configured to provid e a convenient means to check accuracy of the flow meter. The flow meter will be consid ered accurate if the measured weight is within 1% of actual weight. Drum Mixer The HMA drum plant shall be equipped with a diversion system wh ere mix can be diverted at startup/shutdown and any time. The drum mixer shall be subject to annual inspection prior to removal of safety features and being readie d for service. The Contractor shall provide the Department a minimum period of 72 hours to in spect the drum mixer while providing at least 72 hour’s notice that the drum mixer is read y for inspection.
Recordation An approved automatic ticket printer system shall be used with all approved HMA drum plants. The requirements for delivery slips for payment of materials measured by weight, as given in the following Sections, shall b e waived: 108.1.3 a., 108.1.3 b., 108.1.3 c., and 108.1.3 d. The automatic printed ticket wi ll be considered as the Weight
Certificate. The dry aggregate weights and binder flow shall be recorded as well as mineral filler and all binder additives. The recordation of materialss hall be printed a minimum of every ten minutes while in production. The requirements of Section 108.1.3 f. - Delivery Slips, shall be met by the weigh slip or ticket, printed by the automatic system, which accompanies each truckload, except for the following changes:
net weight of each truckload.
a malfunction as described in 401.074 c.).
the requirements of Section 108 - Payment, the scales shall be inspected and sealed by the State Sealer (or approved alternative) as often as the Departme nt deems necessary to verify their accuracy. Plant scales shall be checked prior to the star t of the paving season, and each time a plant is moved to a new location. Subsequent checks wil l be made as determined by the Resident. The Contractor will have at least ten 50 pound m asses for scale testing at batch plants. At Contractor’s option, the Contractor can use on e single test weight that has been checked on sealed scales. This weight shall be 1,000 lbs. or greater. At least twice during each 5 days of production either of the following checks will be performed:
sealed by the State Sealer of Weights and Measures within the p ast 12 months. The inspector will notify the producer to take corrective action on any discrepancy over 1.0%. The producer may continue to operate for 48 hours under the fol lowing conditions. 1 If the discrepancy does not exceed 1.5%; payment will still b e governed by the printed ticket. 2 If the discrepancy exceeds 1.5%, the plant will be allowed to operate as long as payment is determined by truck platform scale net weight.
If, after 48 hours the discrepancy has not been addressed and r educed below 1.0%, than plant operations will cease. Plant operation may resume after the discrepancy has been brought within 1.0%.
accuracy and sensitivity of each scale within the normal weighi ng range and to assure that the interlocking devices and automatic printer system are funct ioning properly. If platform scales are not readily available, a weight with a known mass-ve rified and sealed annually by a licensed scale company, may be used by hanging weight from si lo or surge hopper, at lower middle and upper third levels upon request to verify scal e accuracy.
continued without
the use of platform truck scales for a period not to exceed the next two working days, providing total weights of each batch are recorded on weight tickets and certif ied by a Licensed Public Weighmaster.
401.08Hauling Equipment Units hauling HMA shall have tight, c lean, and smooth
metal bodies, which have been thinly coated with a small amount of approved release agent to prevent the mixture from adhering to the bodies. Release age nts that dissolve or strip asphalts, including diesel fuel, will not be allowed. All mix haul units shall have a cover of canvas or other water repellent material capable of heat retention, which completely covers the mixture. The cover shall be securely fastened on the truck, unless unloading. All mix haul units shall have a n opening on both sides, which will accommodate a thermometer stem. The opening shall be located near the midpoint of the body, at least 12 in above the bed.
401.09Pavers The Contractor shall use pavers meeting the requ irements of this section
unless otherwise authorized by the Department. Pavers shall be self-contained, self- propelled units with an activated heated screed capable of placing courses of Hot Mix Asphalt Pavement in full lane widths specified in the contract on the main line, shoulder, or similar construction. Pavers shall be of sufficient class and size to place Hot Mix A sphalt Pavement over the full width of the mainline travel way with a 10 ft minimum main screed with activated extensions. The Contractor shall place Hot Mix Asphalt Pavement on the main line with a paver using an automatic grade and slope controlled screed, unl ess otherwise authorized by the Department. The controls shall automatically adjust the sc reed and increase or decrease the layer thickness to compensate for irregularities in the pre ceding course. The controls shall maintain the proper transverse slope and be readily adjus table so that transitions and superelevated curves can be properly paved. The controls shall operate from a fixed or moving reference such as a grade wire or ski type device (floating beam) with a minimum length of 30 ft, a non-contact grade control with a minimum spa n of 24 ft, except that a 40 ft reference shall be used on Expressway projects. The Contractor shall operate the paver in such a manner as to p roduce a visually uniform surface texture and a thickness within the requirements of Section 401.11 - Surface Tolerances. The paver shall have a receiving hopper with suffi cient capacity for a uniform spreading operation and a distribution system to place the mixture uniformly, without segregation in front of the screed. The screed assembly shall produce a finished surface of the required evenness and texture without tearing, shoving, or gouging the mixture. Pavers with extendible screeds shall have auger extensions and tunnel extenders as per the manufacturer’s recommendations, a copy of which shall be availa ble if requested. The Contractor shall have the pa ver at the project site suffici ently before the start of paving operations to be inspected and approved by the Departmen t. The Contractor shall repair or replace any paver found worn or defective, either bef ore or during placement, to