4-8 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.
401.08 Hauling 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.
401.09 Pavers 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 plac ing 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 (float ing 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 Sect ion 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 mixt ure 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 4-9 the satisfaction of the Department. Pavers that produce an une venly textured or non- uniform mat will be repaired or replaced before continuing to p lace HMA on MaineDOT projects. On a daily basis, the C ontractor shall perform densi ty testing across that mat as detailed in Section 401.191 Quality Control - Method A, B & C.
401.10 Rollers Rollers shall be static steel, pneumatic tire, oscillatory, or approved
vibrator type. Rollers shall be in good mechanical condition, capable of starting and stopping smoothly, and be free from backlash when reversing dir ection. Rollers shall be equipped and operated in such a way as to prevent the picking u p of hot mixed material by the roller surface. The use of rollers, which result in crushi ng of the aggregate or in displacement of the HMA will not be permitted. Any Hot Mix Asp halt Pavement that becomes loose, broken, contaminated, shows an excess or deficie ncy of Performance Graded Asphalt Binder, or is in any other way defective shall b e removed and replaced at no additional cost with fresh Hot Mix Asphalt Pavement, which shal l be immediately compacted to conform to the adjacent area. The Contractor shall repair or replace any roller found to be w orn or defective, either before or during placement, to the satisfaction of the Departme nt. Rollers that produce grooved, unevenly textured or non-uniform mat will be repaired or replaced before continuing to place HMA on MaineDOT projects. The type of rolle rs to be used and their relative position in the compaction sequence shall generally be the Contractor’s option, provided specification densities are attained and with the foll owing requirements:
a.On variable-depth courses, the first lift of pavement over g ravel, reclaimed pavement, on irregular or milled surfaces, or on bridges, at least one ro ller shall be 16 ton pneumatic-tired. Pneumatic-tired rollers shall be equipped wit h skirting to minimize the pickup of HMA materials from the paved surface. When requir ed by the Resident, the roller shall be ballasted to 20 ton.
b.Compaction with a vibratory or steel wheel roller shall prec ede pneumatic-tired rolling, unless otherwise authorized by the Department.
c.Vibratory rollers shall not be operated in the vibratory mod e when checking or cracking of the mat occurs, or on bridge decks.
d.Any method, which results in cracking or checking of the mat , will be discontinued and corrective action taken.
e.The use of an oscillating steel roller shall be required to compact all mixtures placed on bridge decks. The maximum operating speed for a steel wheel or pneumatic roll er shall not exceed the manufacturer’s recommendations, a copy of which shall be availa ble if requested.
401.11 S urface Tolerances The Department will check the follow ing surface tolerances:
a.) Longitudinally: The pavement surface profile shall be free of deviations in excess of +/- ¼ inches from the required pa vement surface profile grade. To verify the surface tolerance a straight plane shall be established using 16 foot s traight edge or a taught string
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 268–269 of 817.