2390Cold-in-Place Recycled and Cold Central Plant Recycling Bituminous

2390.1DESCRIPTION

This Work consists of the construction of Cold-in-place recycled (CIR) and Cold central plant recycling (CCPR) Bituminous pavement on a prepared surface. A General See MnDOT Grading and Base website for forms and Grading and Base Manual. Bituminous Material for mixture is the liquid bituminous Material added to Recycled asphalt pavement (RAP) to produce the CIR/CCPR mixture. Cold in-place recycled (CIR) bituminous Layer is constructed by milling the existing bituminous which produces RAP. The RAP is mixed with a bituminous Material for mixture, placed and compacted to produce a CIR Layer. Additional additives, if required, such as rock or cement, are placed on the pavement prior to milling. Cold central plant recycling (CCPR) bituminous is constructed by milling the existing bituminous or using previously milled HMA to produce RAP. The RAP is crushed, screened, mixed with a bituminous Material for mixture (and other additives if required), hauled to the placement destination, placed and compacted to produce a CCPR Layer. B Design Parameters A CIR/CCPR mix design is recommended to determine the method (foaming or emulsion), bituminous grade, and amount of additives needed to construct CIR/CCPR. The mix design criteria for CIR/CCPR is located in the Grading and Base Manual. Design requirements are listed on Form G&B-408. Contractor is required to meet the mix design.

2390.2MATERIALS

A CIR/CCPR Mix Design Parameters .......................................................................... Form G&B-408 B Portland Cement or Blended Hydraulic Cement ....................................................... 3101 or 3103

2390.3CONSTRUCTION REQUIREMENTS

A General Correct and retest all failing areas. Before beginning operations, remove vegetation and topsoil adjacent to the surface. The gradation requirement for RAP is 97 - 100 percent passing the 1 1/4 inch Sieve and 99 - 100 percent passing the 1 1/2 inch Sieve. Correct, at no additional cost to the Department, bumps and dips in the profile greater than 1 inch in 25 feet. Do not allow rollers or other construction equipment to remain stationary on CIR/CCPR. Do not permit traffic (including construction traffic) on the CIR/CCPR Layer for at least two hours after final rolling or emulsion breaks (if applicable), whatever is longer. Repair structures damaged by Contractor operations, neglect, or negligence. Provide water in order to obtain Optimum Moisture Content. Atmospheric temperature and predicted weather requirements are determined by the Engineer . CIR or place CCPR when:

asphalt

Mill the existing pavement to the Plan depth and width. Process paving fabric encountered during milling operations to less than 5 inches in any dimension. Additional requirement for CCPR: Place material in even Lifts no greater than 4 inches in thickness. B Equipment For foamed asphalt applications, the Equipment must accurately foam bituminous Material, uniformly add specified water, and provide samples of the foamed bituminous Material through a sampling nozzle. Additional requirement for CIR: Use self-propelled Equipment with the ability to mill, crush, screen, size, and mix the RAP along with the required recycling agents to produce a uniform homogeneous product. Additional requirement for CCPR: Use Equipment with the ability to crush, screen, size, and mix the RAP along with the required recycling agents to produce a uniform homogeneous product. B.1 Milling Unit Use a self-propelled milling machine with a minimum 6 foot ski or multi point measuring device for milling control, equipped with automatic depth and cross-slope controls, and ability to maintain a constant cutting depth within ±1/4 inch of Plan depth in one pass.

B.2 Crushing/Sizing Unit Use a crushing/sizing unit with the ability to crush and size RAP to the gradation requirement in 2390.3A, “General,” and equipped with a “closed loop” system that returns oversized Materials to the crusher. B.3 Mixing Unit Use a pug mill mixing unit with the ability to thoroughly mix the RAP while injecting the bituminous Material for mixture and automatically metering it to within 0.1 percent. B.4 Single Train Crushing and Mixing Unit In lieu of meeting the Equipment requirements of 2390.3B.1, “Milling Unit,” 2390.3B.2,”Crushing/Sizing Unit,” and 2390.3B.3, “Mixing Unit,” the Contractor may use a single milling, crushing, sizing, and mixing unit with the following characteristics:

as a down-pressure monitoring system to ensure the recycler stays in the cut

requirements of 2390.3A, “General”

water and bituminous Material for mixture and automatically meter the Material within 0.1 percent

up by a Material transfer machine and placed into a paver

into a paving hopper B.5 Vane Feeder When cement is required for CIR, use a vane feeder capable of uniformly spreading the cement on the Road surface before recycling. B.6 Paver Use a paver equipped with a 20 foot ski meeting the requirements of 2360.3B.2.a, “Paver.” B.7 Bituminous Material for Mixture Supply Tankers If foaming is required, equip the tankers with a visible thermometer that measures the temperature of the liquid bituminous Material for mixture. B.8 Rollers B.8.a Steel Wheeled Rollers Compact with a steel wheeled roller(s) meeting the requirements of 2360.3B.2.e(1), “Steel Wheeled Rollers” equipped with a water spray system. B.8.b Pneumatic Tired Roller Compact with a pneumatic tired roller(s) with a minimum weight of 25 tons meeting the requirements of 2360.3B.2.e(2), “Pneumatic Tired Rollers.”

C Bituminous Material for Mixture Parameters Incorporate the bituminous Material for mixture at the rate designated on the mix design. However, after consultation with the Contractor, the Engineer may direct the Contractor to vary the application rate of bituminous Material for mixture compared to the mix design for areas of pulverized bituminous which the Engineer believes are either too rich or too dry. Maintain bituminous Material for foaming within ± 10°F of the optimum temperature recommended by the mix design (note that bituminous must also meet expansion ratio and half -life foaming tests). If the mix design does not provide a recommendation, maintain the foamed asphalt temperature between 305°F and 325°F. D Cement Control For CIR, spread cement using a computerized vane feeder in a manner that minimizes dusting, i.e. do not spread when the wind is strong enough to coat vehicles and/or the environment. For CIR and CCPR, control the cement content to within ± 0.5 pounds/square yard, of the design target. For CIR, start mixing operations, no longer than 1/2 hour after cement placement on Roadway. For CCPR, place and compact, no longer than 2 hour after cement incorporation. E Mixing Mix the crushed RAP, bituminous Material for mixture, and cement into a homogenous mixture. Adjust the water application rate based on mixture consistency, coating, and dispersion of the recycled Materials. F Placement Do not heat the paver screed. Spread the CIR Material in one continuous pass to the Plan width in one Lift. Ensure that the mix does not segregate. Pave before emulsion breaks. G Compaction G.1 General Correct, at no additional cost to the Department, bumps and dips in the profile greater than 1 inch in 25 feet. Do not allow rollers or other construction Equipment to remain stationary on CIR/CCPR. Do not permit traffic (including construction traffic) on the CIR/CCPR Layer for at least two hours after final rolling or emulsion breaks (if applicable), whatever is longer. Use visual observations of check cracking and shoving to prevent over -rolling. Compact using the criteria in 2390.3G.2, “Control Strip.” Within 48 hours of CIR/CCPR, recompact areas represented by density measurements below 98 percent of the target density determined from the control strip, roll until ≥98 percent density is achieved. Do not over-roll to the point where checking of the surface occurs. Some areas may not achieve 98 percent density due to field conditions.

G.2 Control Strip Comply with 2215.3F.7, “Control Strip,” except establish a new rolling pattern by performing a new control strip when 98 percent of target density is not achieved on two consecutive QC readings. If using 2390.3B.4, “Single Train Crushing and Mixing Unit,” note speed during the control strip and do not subsequently exceed that speed during further operations. H Contractor Quality Control (QC) Perform Contractor QC testing and submit required forms, required in the Schedule of Materials Control. Submit results to the Engineer electronically within 24 hours of the completion of the tests. I Department Quality Assurance (QA) Test according to the Schedule of Materials Control. J Profile, Curing and Surface Requirements Maintain the CIR layer in a smooth, compacted condition free of ruts, distortions, potholes, loose Aggregate, and to the profile and cross-section until the placement of the bituminous. Remove loose Aggregate on the surface immediately before placing the bituminous. Repair ruts, potholes, washboarding, and other distortions. K Fog Seal and Bituminous Requirements If requested by the Engineer, apply a CSS-1h bituminous fog seal per 2355, “Bituminous Fog Seal” at a rate of 0.08 – 0.16 gallons per square yard. L Bituminous Requirements Place the bituminous:

CIR/CCPR, at any location, has been injected and compacted (note that the 14 Calendar Day requirement may be extended with concurrence of the Engineer, if large rainfall events hinder the curing of the CIR)

Quality Compaction per 2106.3G.2, “Quality Compaction”

the next Layer, and the moisture content of the CIR/CCPR does not cause a failure to the next Material placement

damage the new surface

2390.4METHOD OF MEASUREMENT

Measure the CIR/CCPR Layer by the square yard. Measure the cement in accordance with 2215, “Reclamation.” Measure the Aggregate in accordance with 2215, “Reclamation.” Measure the bituminous Material for mixture in accordance with 2215, “Reclamation.” Measure the bituminous Material for fog seal in accordance with 2355, “Bituminous Fog Seal.”

2390.5BASIS OF PAYMENT

The Department will pay for the correction of in-situ areas that are unstable through no fault of the Contractor’s operations, if directed by the Engineer, as Extra Work in accordance with 1402, “Contract Revisions.”

The Department will pay for cement in accordance with 2215, “Reclamation.” The Department will pay for Aggregate in accordance with 2215, “Reclamation.” The Department will pay for bituminous Material for mixture in accordance with 2215, “Reclamation.” The Department will pay for bituminous Material for fog seal in accordance with 2355, “Bituminous Fog Seal.” The Contract Unit Price for the CIR/CCPR includes the cost of milling, production, testing, placement, occasional variations in bituminous pavement thickness, compacting, removing vegetation and topsoil adjacent to the surface, water, and required and necessary maintenance including cleaning the surface. The Department will pay for CIR/CCPR Layer on the basis of the following schedule: Item No. Item Unit

2390.504 Cold-In-Place Recycled/Cold Central Plant Recycling Bituminous square yard