3-13 SECTION 308 FULL DEPTH RECYCLING WITH CEMENT
308.01 Description This work shall consist of pulverizin g a portion of the existing
roadway structure into a homogenous mass, stabilizing the mater ial with cement and placing and compacting this material to the lines, grades, and dimensio ns shown on the plans or established by the Resident. MATERIALS
308.02 Pulverized Material Pulverized material shall con sist of the existing asphalt
pavement and one inch or more as specified of the underlying gr avel, pulverized, and blended into a homogenous mass. Pulverized material will be pr ocessed to 100 percent passing a 2 in square mesh sieve. 308.021 New Aggregate and Additional Recycled Material N ew aggregate, if required by the contract, shall meet the requirements of Subsec tion 703.10 - Aggregate for Untreated Surface Course and Leveling Course, Type A. Aggregate Subbase Course Gravel Type D processed to 100 percent passing a 2 inch square mesh si eve and meeting the requirements of 703.06 – Aggregate for Base and Subbase may be used in areas requiring depths greater than 2 inches. New aggregate will be measured an d paid for under 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 in square mesh sieve. Recycled material shall be conditionally acc epted at the source by the Resident. It shall be free of winter sand, granular fill, const ruction 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 8.09. 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. 308.022 Portland Cement The Portland Cement shall be Typ e I or II meeting the requirements of AASHTO M85. 308.023 Water Water shall be clean and free from delete rious concentrations of acids, alkalis, salts or other organic or chemical substances. EQUIPMENT 3-14
308.03 Pulverizer The pulverizer shall be a self-propell ed machine, specifically
manufactured for full-depth recycling work and capable of reduc ing the required existing materials to a size that will pass a 2 in square mesh sieve. T he 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. 308.031 Cement Spreader Spreading of the Portland cemen t shall be done with a spreader truck designed to spread dry particulate (such as Port land Cement or Lime) or other approved means to insure a uniform distribution across the road way and minimize fugitive dust. Pneumatic application, including through a slotted pipe, will not be permitted. Other systems that have been developed include fog systems, vacuum sy stems, etc. Slurry applications could also be accepted. The Department reserves t he right to accept or reject the method of spreading cement based on the concerns specified herein. The Contractor shall provide a method for verifying that the correct amount of cement is being applied. Health and Safety/Right-to-Know Portland cement is considered a hazardous chemical under US OSHA Hazard Communication Rule 29 CFR 1910.120, theref ore, all Contractors and Subcontractors are required to notify their workers of the potential health hazards associated with working with Portland cement. In no area of the work site, where cement or cement-pavement-gr avel combination is being applied, re-worked with reclaimer, rolled or graded, shal l respirable dust be allowed to exceed the NIOSH [1974] established respirable dust standard (R DS) recommended exposure limit (REL) of 0.05 mg/m3 (for up to a 10 hour workday during a 40 hour work week). The Contractor shall notify the Resident before commencing any work that involves Portland cement application, reclaiming, rolling, or grading. The Contractor shall designate a Hazardous Waste Operations “C ompetent Person” to provide direct on-site supervision plus health and safety mo nitoring for work in the Portland cement impacted sections of the project. The Competen t Person shall have certified training and experience in field implementation of th e aforementioned regulations. Submittals The Contractor shall submit a site spec ific Health and Safety Plan (HASP) to the Resident at least two weeks in advance of any Por tland cement related work on the project. Health and Safety Monitoring In any area of the proj ect where Portland cement is being worked, the Contractor’s designated Competent Person shal l monitor the worker breathing zone for respirable dus t. In the event the OSHA res pirable dust REL is exceeded, the Contractor’s Competent Person shall direct operations to ce ase. Operations will not recommence until the situation is corrected and respirable air returns to acceptable levels. The Contractor shall provide all required health and safety mon itoring equipment. 3-15
308.04 Placement Equipment Placement of the Full Depth r ecycled material to the
required slope and grade shall be done with an approved highway grader or by another method approved by the Resident.
308.05 Rollers The full depth recycled material shall be rolled with a vibratory pad
foot roller, a vibratory steel drum soil compactor and a pneuma tic tire roller. The pad foot roller drum shall have a minimum of 112 tamping feet 3 inches i n height, a minimum contact area per foot of 17 in2, and a minimum width of 84 inches. The vibratory steel drum roller shall have a minimum 84 inches width single drum. The pn eumatic tire roller shall meet the requirements of Section 401.10 and the minimum allowab le tire pressure shall be 85 psi. MIX DESIGN The Department will supply a mix design for the recycling work based on test results from pavement and soil analysis taken to the design depth. The Department will provide the following information prior to construction:
1.Percent of Portland cement to be used. 2. Optimum moisture content for proper compaction. 3. 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
308.06 Pulverizing The entire depth of existing pavement shall be pulverized
together with approximately 1 i nch or more of the underlying gr avel into a homogenous mass. All pulverizing shall be done with equipment that will p rovide a homogenous mass of pulverized material, processed in-place, which will pass a 2 in square mesh sieve.
308.07 Weather Limitations When Portland cement is used, full depth recycled
work shall be performed when; a Cement stabilizing operations will be allowed between May 15th and September 15th inclusive in Zone 1 - Areas nort h of US Route 2 from Gilead to Bangor and north of Route 9 from Bangor to Calais. Cement stabilizing will be allowed betwe en May 1st and September 30th inclusive in Zone 2 - Areas s outh of Zone 1 including the US R oute 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. 3-16 d During generally dry conditions, or when weather conditions a re such that proper pulverizing, adding, mixing, and c uring can be obtained using p roper procedures, and when compaction can be accomplished as determined by the Resident. e When the surface is not frozen and when overnight temperature s are expected to be above 32°F. f Wind conditions as such that the spreading of cement on the r oadway ahead of the recycling machine will not adversely affect the operation (ceme nt will not be blown away).
308.08 Surface Tolerance The complete surface of the Ful l Depth Reclamation
course shall be shaped and maint ained to a tolerance, above or below the required cross sectional shape, of ⅜ inch.
308.09 Full Depth Recycling Procedure New aggregate or r ecycled material meeting
the requirements of Section 308.021 - New Aggregate and Additio nal Recycled Material shall be added as necessary to restore cross-slope and/or grade before pulverizing. Locations will be shown on the plans or described in the construction not es; the Resident may add other locations while construction of the project is in progres s. The Contractor will use recycled material to the extent it is available, in lieu of new aggregate. The material shall then be pulverized, processed, and blended into a homogeneous m ass passing a 2 in square mesh sieve. Material found not pulverized down to a 2 in size w ill be required to be reprocessed by the recycler with successive passes until approv ed by the Resident. 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 squar e mesh sieve. The resultant material shall be graded and compacted to the cro ss-slope and profile shown on the plans or as directed by the Resident. The Contract or will also be responsible for re-establishing the existing profile grade. The completed s urface of the full depth recycled course shall be shaped and maintained to a tolerance, above or below the required cross sectional shape, of ⅜ inch. The initial reclaiming proces s density requirements will be the same as Section 308.101 unless otherwise directed by the Re sident. Following completion of the initial reclaiming process cement s hall be spread uniformly over the full width of roadway to be recycled just prior to eac h pass of the stabilizing operation, in a continuous process by means of a mechanical spr eader. Dry stabilizing agents shall be spread at the prescribed rate in t he mix design as provided by the Department. These additives shall then be uniformly blended int o a homogeneous mass until an apparent uniform distribution has occurred. The Resident ma y adjust the rate of application as necessary. Sufficient water shall be added through the recycler head durin g the recycling process to ensure thorough blending to meet the optimum moisture for compa ction as specified. Water shall be added only by means of a controlled system on the recy cling machine. Care shall be taken to prevent excessive wetting. A second water truck may be required during 3-17 recycling operations to assist in the compaction and water cont rol efforts. The rate of water supplied shall be kept constant unless changed due to project m aterial changes. The resultant material shall be graded and compacted to the cro ss-slope and profile shown on the plans or as directed by the Resident. The Contract or will also be responsible for re-establishing the existing profile grade. The completed s urface of the full depth recycled course shall be shaped and maintained to a tolerance, above or below the required cross sectional shape, of ⅜ in. Areas not meeting this toleranc e will be repaired as described in Section 308.091. After compaction, the roadway surface shall be treated with a l ight application of water, and rolled with pneumatic-tired rollers to create a close-knit texture. The finished layer shall be free from:
A.Surface laminations, B. Segregation of fine and coarse aggregate, C. Corrugations, centerline differential, potholes, or any othe r defects that may adversely affect the performance of the layer. The Contractor shall protect a nd maintain the recycled layer un til a lift of pavement is applied. Frequent light watering shall be performed to keep th e finished cement stabilized material moist for at least 48 hours. Watering will continue fr om 48 hours to 1 week if the equipment is available on-site. Any damage or defects in the la yer shall be repaired immediately. An even and uniform surface shall be maintained. The recycled surface shall be swept prior to hot mix asphalt placement. 308.091 Repairs Repairs and maintenance of the recycled layers, during and after the curing period, resulting from damage caused by traffic, wea ther or environmental conditions, or resulting from damage caused by the Contractor’s operations or equipment, shall be completed at no additional cost to the Department. Low areas will be repaired using a hot mix asphalt shim. Areas up to 1 in high can be repaired by either milling the high area or shimming the low ar eas adjacent to the high area with hot mix asphalt areas greater than 1 in high will be repai red by shimming the low areas adjacent to the high area with hot mix asphalt. All repair work will be done with the Resident’s approval at the Contractor’s expense. TESTING REQUIREMENTS
308.10 Quality Control The Contractor shall operate in ac cordance with the
approved Quality Control Plan (QCP) to assure a product meeting the contract requirements. The QCP shall meet the requirements of Section 106.4 - Quality Control and this Section. The Contractor shall not begin recycling operations until the D epartment approves the QCP in writing. Prior to performing any recycling process, the Department and t he Contractor shall hold a Pre-recycle conference to discuss the recycling schedule, typ e and amount of equipment to 3-18 be used, sequence of operations, and traffic control. A copy o f the QC random numbers to be used on the project shall be provided to the Resident. All field supervisors including the responsible onsite recycling process supervisor shall attend th is meeting. The QCP shall address any items that affect the quality of the Recycling Process including, but not limited to, the following:
A.Sources for all materials, including New Aggregate and Addit ional Recycled Material.
B.Make and type of rollers including weight, weight per inch o f steel wheels, and average contact pressure for pneumatic tired rollers. C. Testing Plan. D. Recycling operations including recycling speed, yield monito ring, procedures for avoiding recycling and curing in i nclement weather, methods to ensure that segregation is minimized, procedures for mix design modification, grading and compacting operations, and methods to introduce water throughout the cement treated layer, and cement application procedure. E. Methods for protecting the finished product from damage and procedures for any necessary corrective action. F. Method of grade checks. G. Examples of Quality Control forms. H. Name, responsibilities, and qualifications of the Responsibl e onsite Recycling Supervisor experienced and knowledgeable with the process.
I.A note that all testing will be done in accordance with AASH TO and MaineDOT/ACM procedures. The Project Superintendent sha ll be named in the QCP, and the r esponsibilities for successful implementation of the QCP shall be outlined. The Contractor shall sample, test, and evaluate the full depth reclamation process in accordance with the following minimum frequencies: MINIMUM QUALITY CONTROL FREQUENCIES Test or Action Frequency Test Method Density 1 per 1000 ft / lane AASHTO T 310 Air Temperature 4 per day at even intervals Surface Temperature At the beginning and end of each days operation Yield of all materials (The daily yield, yield since last test, and total project yield.) 1 per 1000 ft / lane The Department may view any QC test and request a QC test at an y time. The Contractor shall submit all QC test reports and summaries i n writing, signed by the appropriate technician, to the Department’s onsite representati ve by 1:00 P.M. on the next working day, except when otherwis e noted in the QCP due to loca l restrictions. The 3-19 Contractor shall make all test results, including randomly samp led densities, available to the Department onsite. The Contractor shall cease recycling operations whenever one of the following occurs:
A.The computed yield differs from the mix design by 10 percen t or more.
B.The Contractor fails to follow the approved QCP. C. The Contractor fails to achieve 98 percent density after c orrective action has been taken.
D.The finished product is visually defective, as determined by the Resident. Recycling operations shall not resume until the Department appr oves the corrective action to be taken. 308.101 Test Strip The contractor shall assemble all ite ms of equipment for the recycling operation on the first day of the recycling work. The Contractor shall construct a test strip for the project at a location approved by the Reside nt. The Responsible onsite Recycling Supervisor will work with Department personnel to det ermine the suitability of the mixed material, cement dispersion within the mixed material , moisture control within the mixed material, and compaction and surface finish. Thetest stri p section is required to:
A.Demonstrate that the equipment and processes produce recycle d layers to meet the requirements specified requirements.
B.Determine the effect on the gr adation of the recycled materi al by varying the forward speed of the recycling machine and the rotation rate of the mil ling drum.
C.Determine the optimum moisture necessary to achieve proper compaction of the recycled layer. D. Determine the sequence and manner of rolling necessary to ob tain the compaction requirements and establish a target TMD. The Contractor and th e Department will both conduct testing with their respective gauges at this time. The test strip shall be at least 300 ft in length of a full lan e-width (or a half-road widthFull recycling production will not start until a passing t est strip has been accomplished. If a test strip fails to meet the requirements of this specification, the Contractor will be required to repair or replace the test strip to the satisfaction of the Resident. Any repairs, replacement, or duplication of the test strip will be at the Contractor’s expense. After the test strip has been pulverized, and the roadway broug ht to proper shape, the Contractor shall add water until it is determined that optimum moisture has been obtained. The test strip shall then be rolled using the specified compact ion equipment as directed until the density readings show an increase in dry density of less th an 1 pcf for the final four roller passes of each roller. The Contractor and Department wil l each determine a target density using their respective gauges by performing several add itional density tests and averaging them. The average of these tests will be used as the target density of the recycled material for QC and Acceptance purposes. 3-20 Following completion of the test strip, compaction of the mater ial shall continue until a density of not less than 98 percent of the test strip target de nsity has been achieved for the full width and depth of the layer . During the construction and compaction of the Full Depth Recycled base, should three consecutive Acceptance test results for density fail to meet a minimum of 95 percent of the target density, or exceed 102 perc ent of target density, a new test strip shall be constructed.. ACCEPTANCE TEST FREQUENCY Property Frequency Test Method In-place Density 1 per 2000 ft / lane AASHTO T 310
308.11 Miscellaneous No new pavement shall be placed on the full depth recycled
pavement until a curing period of 48 hours has elapsed. If incl ement weather occurs, the Department reserves the right to extend the curing period. Bet ween 24 and 48 hours after compaction, the finished course shall be vibrated with between 2 and 4 passes of a 12 ton minimum weight steel-wheel vibratory roller, traveling at a spe ed of approximately 2 mph and vibrating at maximum amplitude (or as directed by Resident) . The section shall have 100 percent coverage exclusive of the outside 1 ft to induce mi nute cracks in the treated base course. Additional passes may be required to achieve the d esired crack pattern or section modulus as directed by the Resident.
308.12 Method of Measurement Full Depth Recycled Pavemen t with Cement will
be measured by the square yard.
308.13 Basis of Payment The accepted quantity of Full De pth Recycled Asphalt
Pavement with Cement will be paid for at the contract unit pric e per square yard, complete in-place which price will be full compensation for furnishing a ll equipment, materials and labor for pulverizing, blending, placing, grading, compacting, and for all incidentals necessary to complete the work. The addition of materials to restore profile grade and/or cross -slope in areas shown on the plans or described in the construction notes will be paid s eparately under designated pay items within the contract. No additional payment will be made f or materials salvaged from the project. Payments will be made under: P a y I t e m P a y U n i t
308.36 Full Depth Recycling With Cement S q u a r e Y a r d
SECTION 309 - FOAMED ASPHALT 3-21 FULL DEPTH RECYCLED PAVEMENT (With Foamed Asphalt)
309.01 Description This work shall consist of pulverizin g a portion of the existing
roadway structure into a homogenous mass, treating the pulveriz ed material with the foamed asphalt process, and placing and compacting this material to th e lines, grades, and dimensions shown on the plans or established by the Resident. MATERIALS 309.020 Pulverized Material Pulverized material shall co nsist of the existing asphalt pavement and one inch or more as specified of the underlying gr avel, pulverized and blended into a homogenous mass. Pulverized material will be pr ocessed to 100 percent passing a 2 in square mesh sieve. 309.021 New Aggregate and Additional Recycled Material New aggregate, if required by the contract, shall meet the requirements of Sectio n 703.10 - Aggregate for Untreated Surface Course and Leveling Course, Type A. Aggregate Subbase Course Gravel Type D processed to 100 percent passing a 2 inch square mesh si eve and meeting the requirements of 703.06 – Aggregate for Base and Subbase may be used in areas requiring depths greater than 2 inches. New aggregate required to restor e grade and/or cross-slope shall be measured and paid for under the appropriate item. Crus her dust required as part of the job mix shall be considered part of the 309 item and will n ot be measured for payment. Recycled material, if required, shall consist of salvaged aspha lt material from the project or from off-site stockpiles that has been processed, prior to u se to 100 percent passing a 2 in 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, const ruction debris, and 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 9.06. 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. 309.022 Asphalt Binder The asphalt binder used in the f oamed asphalt process shall be Performance Grade 64-28 or 58-28 meeting the requirements of AASHTO M320. 309.023 Portland Cement The Portland Cement shall be Ty pe I or II meeting the requirements of AASHTO M85. 309.024 Hydrated Lime Hydrated Lime shall meet the requ irements of AASHTO M216.
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 230–238 of 817.