3-6 of 703.06 – Aggregate for Base and Subbase may be used in areas requiring depths greater than 2 inches. New aggregate, will be measured and paid for und er the appropriate item. Recycled material, if required, shall consist of salvaged aspha lt material from the project or from off-site stockpiles that has been processed before use to 100 percent passing a 2 inch square mesh sieve. Recycled material shall be conditionally ac cepted at the source by the Resident. It shall be free of winter sand, granular fill, cons truction debris, or other materials not generally considered asphalt pavement. Recycled material generated and salvaged from the project shall be used within the roadway limits to the extent it is available as described in 30 7.09. No additional payment will be made for material salvaged from the project. Recycled material supplied from off-site stockpiles shall be p aid for as described in the contract, or by contract modification. 307.022 Emulsified Asphalt Stabilizer. If required, the emulsi fied asphalt stabilizer shall be grade MS-2, MS-4, SS- 1, or CSS-1 meeting the requireme nts of Subsection 702.04 Emulsified Asphalt. 307.023 Water Water shall be clean and free from deleterious concentrations of acids, alkalis, salts or other organic or chemical substances. 307.024 Portland Cement If required, Portland Cement shall be T ype I or II meeting the requirements of AASHTO M85. 307.025 Hydrated Lime If required, Hydrated Lime shall meet the requirements of AASHTO M216. EQUIPMENT
307.03 Pulverizer The pulverizer shall be a self-propelled mac hine, specifically
manufactured for full-depth recycling work and capable of reduc ing the required existing materials to a size that will pass a 2 inch square mesh sieve. The machine shall be equipped with standard automatic depth controls and must maintain a cons istent cutting depth and width. The machine also shall be equipped with a gauge to show depth of material being processed.
307.04 Liquid Mixer Unit or Distr ibutor. If treatment of the r ecycled layer with
emulsified asphalt is required by the contract, a liquid mixing unit or distributor shall be used to introduce the emulsified asphalt stabilizer into the pu lverized material. The mixing unit shall contain a liquid distribution and mixing system whic h has been specifically manufactured for full-depth recycling work, capable of mixing t he pulverized material with an evenly metered distribution of emulsified asphalt into a hom ogeneous mixture, to the depth and width required. 3-7 The mixing unit shall be designed, equipped, maintained, and op erated so that emulsified asphalt stabilizer at constant temperature may be ap plied uniformly on variable widths of pulverized material up to 6 feet at readily determine d and controlled rates from 0.01 to 1.06 gal/yd2 with uniform pressure and with an allowable variation from any specified rate not to exceed 0.01 gal/ yd2. Mixing units shall include a tachometer, pressure gages, and accurate volume measuring devices or a calibrated ta nk and a thermometer for measuring temperatures of tank contents. 307.041 Cement or Lime Spreader If required by the contract, spreading of the Portland Cement or Hydrated Lime shall be done with a spreader truck des igned to spread dry particulate (such as Portland Cement or Lime) or other approved means to insure a uniform distribution across the roadway and minimize fugitive dust. Pne umatic application, including through a slotted pipe, will not be permitted. Other systems that have been developed include fog systems, vacuum systems, etc. Slurry app lications may also be accepted. The Department reserves the right to accept or rejec t the method of spreading cement. The Contractor shall pr ovide a method for verifying th at the correct amount of cement is being applied.
307.05 Placement Equipment Placement of the Full Depth recycle d material to the
required slope and grade shall be done with an approved highway grader or by another method approved by the Resident.
307.06 Rollers The full depth recycled material shall be rolle d with a vibratory pad foot
roller, a vibratory steel drum soil compactor and a pneumatic t ire roller. The pad foot roller drum shall have a minimum of 112 tamping feet 3 inches in heigh t, a minimum contact area per foot of 17 inch2, and a minimum width of 84 inches. The vibratory steel drum ro ller shall have a minimum 84 inch width single drum. The pneumatic t ire roller shall meet the requirements of Section 401.10 and the minimum allowable tire p ressure shall be 85 psi. MIX DESIGN If treatment of the recycled layer with emulsified asphalt is r equired by the contract, the Department will supply a mix design for the emulsified asphalt stabilized material based on test results from pavement and soil analysis taken to the desig n depth. The Department will provide the following information prior to construction:
1.Percent of emulsified asphalt to be used. 2. Quantity of lime or cement to be added.
3.Optimum moisture content for proper compaction.
4.Additional aggregate (if required). After a test strip has been completed or as the work progresses , it may be necessary for the Resident to make necessary adjustments to the mix design. C hanges to compensation will be in accordance with the Mix Design Special Provision. CONSTRUCTION REQUIREMENTS 3-8
307.06 Pulverizing The entire depth of existing pavement shall be pulverized together
with 1 inch or more of the unde rlying gravel into a homogenous mass. All pulverizing shall be done with equipment that will provide a homogenous mass of p ulverized material, processed in-place, which will pass a 2 inch square mesh sieve.
307.07 Weather Limitations Full depth recycled work shall be p erformed when;
a Recycling operations will be allowed between May 15th and September 15th inclusive in Zone 1 - Areas north of US Rout e 2 from Gilead to Bangor and no rth of Route 9 from Bangor to Calais. Recycling will be allowed between May 1st and September 30th inclusive in Zone 2 - Areas south of Zone 1 i ncluding the US Route 2 and Route 9 boundaries. b The atmospheric temperature, as determined by an approved the rmometer placed in the shade at the recycling location, is 50°F and rising. c When there is no standing water on the surface. d During generally dry conditions, or when weather conditions a re such that proper pulverizing, mixing, grading, finishing and curing can be obtai ned using proper procedures, and when compaction can be accomplished as determined by the Re sident. e When the surface is not frozen and when overnight temperature s are expected to be above 32°F. f Wind conditions are such that the spreading of lime or cement on the roadway ahead of the recycling machine will not adversely affect the operation.
307.08 Surface Tolerance The complete surface of the Full Dept h Recycled course shall
be shaped and maintained to a tolerance, above or below the req uired cross sectional shape, of ⅜ inch.
307.09 Full Depth Recycling Procedure New aggregate or recycle d material meeting the
requirements of Section 307.021 - New Aggregate and Additional Recycled Material, shall be added as necessary to restore cross-slope and/or grade befor e pulverizing. Locations will be shown on the plans or described in the construction notes. T he Resident may add other locations while construction of the project is in progress. The Contractor will use recycled material to the extent it is available, in lieu of new aggregat e. The material shall then be pulverized, processed, and blended into a homogeneous mass pass ing a 2 inch square mesh sieve. Material found not pulverized down to a 2 inch size will be required to be reprocessed by the recycler with successive passes until approved by the Re sident. Should the Contractor be require d to add new aggregate or recyc led material to restore cross-slope and/or grade after the initial pulverizing process, those areas will require re- processing to blend into a homogenous mass passing a 2 in squa re mesh sieve.
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 223–225 of 817.