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Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling (2021)

Chapter: Appendix B - Individual Survey Responses

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Page 125
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
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Page 126
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
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Page 126
Page 127
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
×
Page 127
Page 128
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
×
Page 128
Page 129
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
×
Page 129
Page 130
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
×
Page 130
Page 131
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
×
Page 131
Page 132
Suggested Citation:"Appendix B - Individual Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2021. Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling. Washington, DC: The National Academies Press. doi: 10.17226/26319.
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Page 132

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125   A P P E N D I X B Individual Survey Responses This appendix details how agency contacts were identified, the response rate and respondents’ job titles, and each individual agency’s response to the survey questions. Developing the Agency Contact List Four AASHTO provisional standards related to cold recycling mix design and material specifications were finalized in 2017. The AASHTO Technical Section 2a for Emulsified Asphalts manages the specification for cold recycling processes with emulsified asphalt (MP 31) and cold recycling mix designs with emulsified asphalt (PP 86). The AASHTO Technical Section 2d for Bituminous Materials manages the specification for cold recycling processes with foamed asphalt (MP 38) and cold recycling mix designs with foamed asphalt (PP 94). The members of these two Technical Sections are the agency staff most likely to have current knowledge of cold recycling projects and processes in their state. The combined membership for the two Technical Sections provided contacts for 41 state agencies and the District of Columbia. Twenty-two of the contacts were members of both Technical Sections. When there were two or more potential contacts for a given state, the initial survey invitation was sent to the first name on the list. If no response was received after two reminder e-mails, then an invitation to take the survey was sent to the next name on the contact list. Contacts for the nine agencies with no members on either Technical Section were identified using referrals from other agencies, personal ASTM committee contacts, and state-specific project articles in trade magazines. Survey Response Rate Individual responses were received from 40 state agencies for an 80% response rate. Not all respondents answered all questions. Only one response per agency was included in the reported survey results. Twenty-nine respondents self-identified, while 11 respondents chose not to provide this information. However, 33 respondents did list their job title: • Materials Engineer (5) • Regional or District Engineer (5) • Maintenance Engineer (4) • Quality Assurance Supervisor (1) • Technical Services Manager (1)

126 Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling • Construction and Materials Bureau Chief (1) • Asphalt Division Chief (1) • Cold Asphalt, Grading, Base, Aggregate Engineer (1) • Pavement Engineer (3) • Civil Engineer Specialist (1) • Asphalt Materials Workgroup Supervisor (1) • Pavement Design Engineer (1) • Chief Maintenance and Asset Management Engineer (1) • Professional Engineer 1 (1) • Engineer of Test (1) • Managing Engineer (1) • Chemical Stabilization Engineer (1) • Director (1) • Pavement Unit Supervisor (1) • Materials and Testing (1) Individual Agency Responses to Survey Questions Question 2: Indicate if you use either of these recycling methods in your area and, if used, how long have you been using each type (check all that apply): Type of Recycling Less than 5 years 5 to 10 years More than 10 years We don't use this method Cold central plant recycling Emulsions CO, IN, MN, MT NY, UT PA AK, AL, AZ, CA, CT, FL, KS, KY, MI, MO, NC, NE, NV, OH, RI, SC, TN, VA Foamed asphalt MN GA, MD, NM, NY, VA CA AK, AL, AZ, CT, IN, FL, KS, KY, MI, MO, MT, NC, NE, NV, OH, RI CIR Emulsions IN, VA CO, DE, GA, IL, MD, MT, ND, NV, OR AZ, CA, CO, IA, ID, MN, MO, NE, NH, NM, NY, PA, SD, UT, VT, WA AK, AL, CT, FL, KS, KY, MI, OH, RI, SC, TN Foamed asphalt SC, VA, TX IL, MO, WI IA, MN, NE, NV, NY AK, AL, AZ, CA, CT, FL, IN, KS, KY, MI, MT, NC, OH, OR, RI, SD, TN, UT, VT The additional comments by respondents follow:

Individual Survey Responses 127   • We have not used any treatment. Have had locals (City of Hilliard and City of Dublin just used CIR and NE Ohio locals have used more often). We have considered possibly trying CIR and CCPR within the next few years. • Very few CCPR, majority CIR. • I believe there is interest in CCPR. • We did only limited amount of jobs using CCPR and CIR techniques. • Have used emulsion in the past but now use foam asphalt exclusively. • We had a trial CCPR with foamed asphalt project ready to go this past summer but had to abort at the last minute. We are actively developing specifications for all four processes with the hope to do some test sections or projects in the near future. • Current VDOT specifications allow for use of emulsion or foamed asphalt for CIR and CCPR. To date, only one project tried using CIR with emulsion and ultimately used foamed. No CCPR projects have used emulsion to date. • The Department does not use these treatments; however, many municipalities do use them. Two companies in our area do most of the work for the municipalities. • CIR with foam has only recently been approved as a standard specification. I would like to use this. • No cold recycling has been performed by Arizona DOT since 2016. • We have only done one project with bituminous, and it was a deep (8 inch) Cold in Place project in Fall 2019. Looking for more candidates as it was successful. • We have placed one test section on a project using CIR with emulsion. • UDOT has used CIR for about 30 years. We have one project with CCPR that was about 7 years ago. We have always used emulsions with our CIR projects. Question 3: Do you have any experience with using the following cold recycling standards? Standards Yes, we have used the standard No, we have NOT used the standard Planning on using the standards in the near future AASHTO MP 31 Standard Specification for Materials for Cold Recycled Mixtures with Emulsified Asphalt CO, DE, MT, NY, TX AK, AL, AZ, CT, GA, IN, KS, MN, MO, NC, NE, NM, NV, PA, RI, UT, VA, WA, WI MD, NM, OH, SC, TN AASHTO PP 86 Standard Practice for Emulsified Asphalt Content of Cold Recycled Mixture Designs MT, NY AK, AL, AZ, CO, CT, GA, IN, KS, MN, MO, NC, NE, NM, NV, PA, RI, UT, VA, WA, WI MD, NM, OH, SC, TN, TX

128 Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling AASHTO PP 94 Standard Specification for Determination of Optimum Asphalt Content of Cold Recycled Mixture with Foamed Asphalt NY, WI AK, AL, AZ, CO, CT, GA, IN, KS, MN, MO, NC, NE, NM, NV, PA, RI, UT, VA, WA, WI MD, NM, SC, TN AASHTO MP 38 Standard Specification for Mix Design of Cold Recycled Mixture with Foamed Asphalt NY, WI AK, AL, AZ, CO, CT, GA, IN, KS, MN, MO, MT, NC, NE, NM, NV, OH, PA, RI, UT, VA, WI MD, NM, SC, TN ARRA CR101 Construction Guide for CIR Using Bituminous Recycling Agents MD, MO, MT, NM, NY AK, AL, CO, CT, GA, IN, KS, MN, NC, NE, NV, OH, PA, RI, UT, VA, WA, WI AZ ARRA CR102 Construction Guide for CCPR Using Bituminous Recycling Agents MD, MO, MT, NM, NY, SC AK, AL, CO, CT, GA, IN, KS, MN, NC, NE, NV, PA, RI, UT, VA, WA, WI AZ, OH ARRA CR201 Mix Design Guidelines for Cold Recycling Using Emulsified Asphalt Agent CA, MD, MT, NM, NY, SC AK, AL, CO, CT, GA, IN, KS, MN, NC, NE, NV, PA, RI, UT, VA, WA, WI AZ, OH, TN ARRA CR202 Mix Design Guidelines for Cold Recycling Using Foamed (Expanded) Agent MD, MO, NM, NY, SC AK, AL, CO, CT, GA, IN, KS, MN, MT, NC, NE, NV, OH, PA, RI, UT, VA, WA, WI AZ, TN ARRA CR301 Quality Control Sampling and Testing Guidelines for Cold Recycling Using Bituminous Recycling Agents DE, MD, MO, MT, NM, NY, SC AK, AL, AZ, CO, CT, GA, IN, KS, MN, NC, NE, NV, PA, RI, UT, VA, WA, WI OH The additional comments by respondents follow: • Plan to possibly have a few projects with CIR and/or CCPR in a few years. • We have developed our own spec based on ARRA specs, and we used it extensively in the past. Since AASHTO specs are relatively new, we will consider them for future jobs. • We started a few years before any standards or guidance really existed. We created specs and our own mix design document. https://www.in.gov/indot/div/mt/itm/pubs/592_testing.pdf. It seems to be working well so why fix what isn't broken? • Wisconsin Specifications: STP 327-010 Cold in Place Recycling (CIR) Asphalt Base Layer, STP 211- 010 Prepare CIR Foundation for HMA Layer, STP 211-020 Prepare Foundation for CIR Base Layer, STP 211-030 Base Repair for CIR Layer. • We are reviewing all the information mentioned and also the Wirtgen manuals as well. • VDOT used BARM and ARRA guidelines for specification development, including test procedures.

Individual Survey Responses 129   • PennDOT Publication 408, Specifications, Section 341 (CIR Base Course) and Section 342 (CCPR Base Course). • I am not familiar by name with many of these called out Standard Specification. • Historical NMDOT standards and specifications. • I am aware of all of these, and we have referenced ARRAs guidelines. I plan to check out the new AASHTO ones shortly. We used Wirtgen procedures on our only foamed project, which are similar. • MoDOT developed a specification based upon ARRA mix design and construction guides for CIR. • Our specification is 02968S. We may adopt some of these in the future, especially the AASHTO specs. Question 4: Indicate the approximate number of lane-miles that are recycled per year (check all that apply): Type of Recycling Less than 50 lane-miles 50 to 100 lane-miles Greater than 100 lane-miles Cold central plant recycling Emulsions AL, AZ, CO, KS, MN, MT, NE, NV, NY, PA, RI, SC, UT, VA, TX IN --- Foamed asphalt AL, AZ, CA, KS, MD, MN, NE, NV, NY, RI, SC, VA NM --- CIR Emulsions AL, AZ, CO, DE, KS, MD, MN, MO, MT, NE, NM, NV, PA, RI, SC, VA, WA CA, IN, NY, UT --- Foamed asphalt AL, AZ, KS, MN, MO, NE, NV, RI, SC, VA NY, WI, TX --- The additional comments by respondents follow: • The number is zero lane-miles in the last year. • MDOT SHA have done only two small jobs per year on an average. May be less than 10 lane-miles per year on an average. • This is an average estimation as the quantity varies per year. In 2018, 128 miles, and in 2019, 140 miles, and in 2020, 34 miles are on the schedule to date. • We have recycled most of our low-volume road pavements that had enough depth with surface treatments. We have done a few higher volume roads with overlay. • WSDOT has done 15 to 20 CIR projects in the past 30 years. The average length of each project was 5 to 10 centerline miles each.

130 Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling • This should be changing in 2020. Two of our five districts are now on board for doing CIR and CCPR. • Historically, NMDOT has led use of CIR with emulsion. Prior to 2000, we were completing 10 to 12 CIR projects per year. Between 2008 and 2018, no CIR projects were completed. In 2018 we completed an approximately 20 lane-mile CIR with success. • SCDOT does hundreds of lane miles of FDR with cement, we are just now breaking into alternatives and partial depth (CIP/CCPR). • Do not use CCPR. CIR has been very limited in Missouri. • Our last CCPR project was about 7 years ago. This project was on SR 191 near Blanding, Utah. The lower layer was CIR, then CCPR was placed on top of that with a double chip seal on top of the CCPR. It is performing well. The last two years we have had just one CIR project each year. Prior to that we had 4 projects in one year. All of these have been performing well. We have our best performance with solventless emulsions and a high effort on getting good density. Question 5: Indicate typical annual average daily traffic (AADT) levels on your recycled pavement projects (check all that apply): Type of Recycling Traffic Levels Up to 10,000 AADT 10,000 to 25,000 AADT More than 25,000 AADT Cold central plant recycling Emulsions CO, MN, MT, UT IN, MT, NY, PA MT Foamed asphalt CA, MD, MN, MT, VA MT, NM, NY, VA MT, VA, TX CIR Emulsions CA, CO, DE, MD, MN, MO, MT, NE, NV, WA IN, MN, MT, NM, NY, PA, VA MN, MT Foamed asphalt MN, MO, MT, NE, NV, VA, WI, TX MN, MT, NY, SC, VA MN, MT, VA The additional comments by respondents follow: • Since 2004 the maximum AADT on an Arizona DOT recycled pavement project was 4,150. However, Arizona DOT has historically used a high float (HF) emulsion and has only recently updated our cold recycling specification to require an engineered emulsion for higher AADT (no projects constructed yet). • It is based on the condition of the pavement. We did not let the high traffic roads deteriorate much.

Individual Survey Responses 131   • Traffic is not and shall not be a factor in using these technologies. The distress type exhibited in the road is what determines what we are going to use. If we have deep cracking, and a good base, we use CCPR. We are currently phasing out our standard 0.2' mill and fill treatment with 0.3' CIR. We do not use foam due to the distance of roads from a bituminous producer. We cannot keep the foam hot enough when we have work in the rural areas of Montana. It is easier for our state to use emulsion for this reason. However, if you are in a state with a reasonable source of bituminous producers, feel free to use foamed asphalt. Just remember that there is a limit on how far you can ship it. Talk to your supplier to determine the radius from the plant. It is fairly far if I remember correctly. • Max ADT volume for CCPR with emulsions and CIR with emulsions is 15,000 and when the daily ESALs are less than 200. If daily ESALs are greater than or equal to 200, then CCPR and CIR are not to be used. • No set policy on AADT but projects to date have all been below the 10,000 AADT. Question 6: Please indicate all barriers that limit the implementation or increased use of cold recycling methods (check all that apply): Barriers Cold Central Plant Recycling CIR Emulsion Foamed Asphalt Emulsion Foamed Asphalt No previous agency experience AK, AL, AZ, GA, MT, NC, NM, NV, OH, SC, TN AK, AL, AZ, GA, IN, MT, NC, NV, OH, SC, TN, TX AK, AL, GA, NC, OH, SC, TN AK, AL, AZ, GA, IN, MT, NC, NM, OH, TN No experienced cold recycling contractors AK, AL, AZ, GA, IN, MT, NC, NM, SC, TN, VA AK, AL, AZ, GA, MD, MT, NC, SC, TN, VA AK, AL, GA, IN, MD, MT, NC, SC, TN, VA AK, AL, AZ, GA, MT, NS, NM, PA, TN, VA Previous unsuccessful experiences --- GA AZ, DE, GA, KS, MD, MO, MT, NE, NM, NV, UT, TX NE, VA Project selection criteria not well defined AZ, GA, IN, MN, RI AZ, GA, MN, RI AZ, GA, IN, MN, PR AZ, GA, MN, RI, WI Lack of availability of materials PA --- --- --- QC/QA testing not well defined MT, OH, SC MD, MT, OH, SC AZ AZ QC/QA testing takes too long in the field GA GA, TX GA GA Lack of construction specifications GA, NM, NV, OH, SC GA, NV, SC GA, OH, SC AZ, GA, NM Excessive time needed before opening to traffic SC MD, TX DE, MD, SC ---

132 Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling The additional comments by respondents follow: • General lack of agency knowledge and experience with modern cold recycling techniques. • These have not been barriers for us. • Colorado DOT has a good CCPR and CIR program in place. • Lack of funding for additional paving programs. • We have created a design flow chart to better select recycling treatments. Had early cases of bad project selection. Figure 602-1A. https://www.in.gov/indot/design_manual/design_manual_2013.htm • We had bad experience with one job because of weather restrictions. • Excessive time needed before opening to traffic used to be a problem for Montana. We recently learned that there are plenty of additives that can be used to allow for traffic on it towards the end of the day. • The primary reason we have moved away from CIR with foam and CIR with emulsion is that our high RAP hot mix is very competitive. High RAP HMA does not require a second subcontractor and it is not sensitive to high precipitation events. • Cost. • Can you do CIR with foamed asphalt? • Not sure it works any better than reclamation, which is inexpensive and effective. • There are no CIR contractors in Missouri. Hot Mix contractors have a strong influence on not implementing CIR or CCPR. • Requires specialized equipment/contractors, not always readily available locally. Change and concerns of “risk” and performance. • The maintenance of traffic (MOT) is a big consideration when selecting a project. The project also needs to have the proper level of distress. Another barrier is having Region material engineers with trust in the CIR process and willingness to use it. There is also a perceived barrier—do we have enough contractors to bid on the work. Right now, we do have a CIR specification that we are gaining experience and confidence with. • Prior CIR projects were performed by “out-of-state” contractors as no locally available contractor. There is a locally based CIR contractor in Virginia now, so minimal concern with experienced contractor. One CIR project did not go well, so there has been some hesitation to use the process previously but is going away as a project is being developed to use CIR in this same region. Recent years have seen an expansion on CCPR contractors/use in the eastern part of the state, but it has been slow to gain momentum in other areas. • Traffic volumes can be an issue when pilot cars are needed. CIR is not done in Western Washington due to weather concerns. Overall, WSDOT has been successful with using CIR practices.

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Cold in-place recycling (CIR) is a process in which 3 to 4 inches of the existing asphalt pavement layers are pulverized, mixed with a recycling agent, and repaved in place. It provides agencies with cost-effective and environmentally friendly pavement maintenance and rehabilitation options for aged asphalt pavements.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 569: Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling compiles and documents information regarding the current state of practice on how CIR and cold central plant recycling (CCPR) technologies are selected, designed, constructed, and evaluated by state departments of transportation (DOTs).

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