Geofoam Applications in the Design and Construction of Highway Embankments (2004)

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A-1 APPENDIX A GEOFOAM USAGE SURVEY: QUESTIONNAIRE

A-2 APPENDIX A GEOFOAM USAGE SURVEY: QUESTIONNAIRE Contents A.1. Introduction ........................................................................................................................................ A-2 A.2. Copy Of Survey.................................................................................................................................. A-3 A.3. Summary Of Results......................................................................................................................... A-10 Tables ....................................................................................................................................................... A-29 ______________________________________________________________________________________ A.1. INTRODUCTION A geofoam usage survey was conducted via a questionnaire developed by the project team to obtain case history information, cost data, design details and other geofoam related information. The final draft version of the questionnaire was submitted to NCHRP via postal mail on September 11, 1999 for the required review and approval. Notice of approval of the submitted draft version was received from NCHRP on October 1, 1999. Distribution of the questionnaire began in early October 1999. Questionnaires were mailed to the designated TRB representative in of each of the 50 states as well as the District of Columbia and Commonwealth of Puerto Rico for distribution to the appropriate local Department of Transportation (DOT) representative. Questionnaires were also sent to the EPS Molders Association (EPSMA) in Crofton, Maryland for distribution to their members as well as to attendees at the American Society of Civil Engineers continuing education seminar titled "Designing with Geofoam Geosynthetic" that was held in Randolph, Massachusetts on October 14-15, 1999. The questionnaire was mentioned on the Internet via the now defunct Geofoam WWW Site (<www.geofoam.org>). Because recipients of the questionnaire were encouraged to copy and distribute it further to interested colleagues, clients, and customers, a 3.5" computer diskette containing the questionnaire document file in Microsoft Word 97 format was included with each paper copy of

A-3 the questionnaire that was distributed. As a result, it is not possible to state exactly how many copies were actually distributed. The official deadline date for responses was November 30, 1999. A copy of the questionnaire is included in this appendix. A summary and synthesis of the survey replies follows the copy of the questionnaire in the appendix. A.2. COPY OF SURVEY Geofoam Usage Survey National Cooperative Highway Research Program (NCHRP) Contract No. HR 24-11 "Guidelines for Geofoam Applications in Embankment Projects" Introduction Geofoam is the generic term for any closed-cell foam material used in a geotechnical application. Geofoam is now recognized as a category of geosynthetic materials and related products in the same way as geotextiles, geomembranes and geogrids. Many different types of foams have been used in geofoam applications over the years, with the first documented applications dating back to the mid 1960s. While several materials have performed satisfactorily in geofoam applications, block-molded expanded polystyrene (EPS block) emerged long ago as the material of choice in most applications for both technical and cost reasons. EPS-block geofoam can be used for several geosynthetic functions or roles. One of the most widely used to date is as lightweight fill material beneath roads. The first documented project for this was the reconstruction of the Flom Bridge approach embankment in Norway in 1972. Thus the use of EPS-block geofoam as a lightweight fill for road construction represents a mature, not experimental, technology with almost 30 years of proven, successful use. This includes numerous projects in the U.S.A. for all types of roads, including those built to Interstate standards. Although EPS-block geofoam for road construction is a well-established technology, it is currently underutilized in U.S. practice. To increase usage in the future, the National Research

A-4 Council through its Transportation Research Board has recently funded a research team (John S. Horvath, Ph.D., P.E. and Dov Leshchinsky, Ph.D.) led by Timothy D. Stark, Ph.D., P.E. at the University of Illinois at Urbana-Champaign to conduct a two-year project. The primary goal of this project is to develop practical and practice-oriented design guidelines and specifications in AASHTO format to facilitate the use of EPS-block geofoam as a lightweight fill in road embankments and bridge approach fills over soft ground. It is anticipated that these documents will encourage engineers to consider design alternatives incorporating EPS-block geofoam more in the future than they have in the past. In keeping with the practice-oriented nature of this project, outside input is being solicited from, and peer review of the project documents will be undertaken by, all three groups that have a major influence on projects involving the use of EPS-block geofoam for road construction: • design engineers acting on behalf of an agency having jurisdiction over roads, • molders (manufacturers) and distributors of EPS-block geofoam, and • construction contractors who build roads. An important part of this outreach is a survey on geofoam usage to obtain input from members of each of these three groups. The attached two-part questionnaire is the primary component of this survey. Thus your completion of this questionnaire is crucial to helping us produce deliverables that are as responsive as possible to the needs of all concerned. Please complete only one questionnaire per organization or company and return your completed questionnaire no later than November 30, 1999 so your input can be included in the final report. A disk of the questionnaire in Word 97 format is also provided for your convenience. Thank you in advance for your cooperation and assistance in completing this questionnaire. Please note that all replies will be held in confidence to the maximum extent allowed by law. Only anonymous summarized results will appear in project reports. Agency or Company Information

A-5 Date: Agency or Company: Name of Person Preparing Questionnaire: Title of Person Preparing Questionnaire: Postal Mail Address: City: State: Zip Code: Telephone Number: Telefax Number: E-mail address: --------------------------------------------------------------------------------------------------------------------- Please return the completed questionnaire no later than November 30, 1999 to Mr. David Arellano, P.E., Graduate Research Assistant: • by postal mail: David Arellano University of Illinois Department of Civil and Environmental Engineering Newmark Civil Engineering Laboratory 205 North Mathews Avenue Urbana, IL 61801-2352 • by telefax: (217) 333-9464 Any questions concerning this questionnaire should be directed to Mr. David Arellano, P.E.: • by e-mail: darellan@students.uiuc.edu

A-6 • by telephone: (217) 333-6940 Part A The purpose of this part is to help us identify extreme opinions, i.e. the perceived best and worst, of EPS-block geofoam technology from the viewpoint of those in practice. If you require additional space for any answer, please use a separate sheet or the back of the sheet. Question A1: Which category best describes the agency or company you represent: design engineer [ ] EPS molder [ ] geofoam distributor [ ] construction contractor [ ] Question A2: Has the agency or company that you represent ever specified, supplied or installed EPS-block geofoam in a lightweight fill for any type of road? No [ ] >>> Please go to Question A3a below. Yes [ ] >>> Please go to Question A3b below. --------------------------------------------------------------------------------------------------------------------- Question A3a: If the answer to Question A2 was “No”, what is the primary reason why not? End of survey. Thank you for participating. --------------------------------------------------------------------------------------------------------------------- Question A3b: If the answer to Question A2 was “Yes”, please proceed with the remainder of the questionnaire. A3bi: To help us understand what is the primary benefit of using EPS-block geofoam so that we can develop this aspect to the fullest, what is the primary positive reason for using this material in road applications?

A-7 A3bii: To help us understand what aspect(s) of EPS-block geofoam most need improvement, what is the primary negative aspect or issue that you can state about this material in road applications? (Note: Exclude cost of the geofoam material itself.) Please proceed to Part B on following page. Part B The purpose of this part is to provide us with information that is useful to some of the specific goals of this project. Question B1: When developing a cost estimate for a design alternative involving EPS-block geofoam for road construction, what one aspect or factor related to the geofoam do you feel the most uncertain or unsure about? This will help us identify those issues requiring the greatest study to help reduce this uncertainty in the future. Question B2: Other than the cost of the geofoam material itself, what item(s) that are related to geofoam (e.g. a reinforced-concrete capping slab, metal inter-block connectors, special site preparation) has your agency or company found to have significant impact on the overall cost of

A-8 a design alternative involving EPS-block geofoam in road construction? This will help us identify those items that need to be closely evaluated for the purpose of optimization or possibly even elimination in design in order to minimize overall project cost. Question B3: Given that there are many factors that influence productivity for placing EPS blocks on a job site, from your experience what is the range of placement costs in dollars-per-cubic-yard or -cubic- meter basis? Question B4: Concerning the geofoam specification used on your most recent project: B4i: What was the source (e.g. State or County Department of Transportation Standard/Provisional Specification, in-house specification, provided by EPS molder or distributor)? B4ii: What one item in, or aspect of, the specification were you least satisfied or comfortable with and would like to have more information on or knowledge about to improve?

A-9 Question B5: If you ever used EPS-block geofoam from a supplier, or if you are a supplier, who offers third-party certification for the manufactured quality of EPS block: B5i: Do you rely solely on this or do you still do supplemental random sampling and testing of the EPS after it is delivered to the job site? B5ii: Have you ever had a problem (such as, but not limited to, material not conforming) with third-party certification? If you did experience a problem, describe the problem and offer suggestions to prevent this problem in the future. Question B6: Overall, what one item would you like us to consider or include in the NCHRP project documents that would be of greatest use to you in designing, supplying or installing EPS- block geofoam for road construction?

A-10 Question B7: Do you have any of the following supporting documentation that you think may be helpful to us in achieving the research objectives and that you would be willing to provide (we will contact you for follow up)? Please check all those items that apply: Plans [ ], Specifications [ ], Design reports [ ], Cost estimates and comparisons [ ], Field instrumentation/Performance data [ ], Photographs [ ]. End of survey. Please feel free to provide any additional comments on a separate sheet. Thank you for participating. A.3. SUMMARY OF RESULTS The questionnaire is divided into two parts: Parts A and B. The purpose of Part A was to identify extreme opinions, i.e. the perceived best and worst, of EPS-block geofoam technology from the viewpoint of those in practice. The purpose of Part B was to provide us with information that would be useful to some of the specific goals of this project. A total of thirty-four questionnaire replies were received by November 30, 1999. One survey was received after the November 30, 1999 deadline and also reviewed. Seven questionnaires were received via e-mail, eight by telefax, and the remaining twenty were received via postal mail. The format for the summary of replies consists of restatement of the question, a summary of replies provided by each respondent, and a synopsis of all the responses except for Questions A1 and A2. The replies to these two questions are presented in a slightly different format. PART A

A-11 Question A1: Which category best describes the agency or company you represent: design engineer [ ] EPS molder [ ] geofoam distributor [ ] construction contractor [ ]. Replies to A1: Twenty-six responses were received from state DOTs, seven replies were obtained from EPS molders, one reply was received from a contractor, and one from an engineering consultant. Table A.1 provides a summary of state DOTs that responded to the questionnaire. The term agency is used in this summary to include all types of respondents. Table A.1. Summary of State DOTs that Responded to the Questionnaire Question A2: Has the agency or company that you represent ever specified, supplied or installed EPS-block geofoam in a lightweight fill for any type of road? No [ ] >>> Please go to Question A3a below. Yes [ ] >>> Please go to Question A3b below. Synopsis of Replies to A2: Twelve of the thirty-five agencies that replied indicated their agency had specified, supplied, or installed EPS-block geofoam as a lightweight fill for road applications. Question A3a: If the answer to Question A2 was “No”, what is the primary reason why not? Replies to A3a: 1. On a few occasions, we have used similar material for insulating, cushioning, etc. purposes , but not yet for lightweight fill. Primary reason is lack of familiarity until few years ago, and since then not having a good project match which we also felt justified the high cost of geofoam as we understand it. (IA DOT)

A-12 2. Although Delaware does have soft soil conditions in certain areas, the potential problems associated with these soils are mitigated by more conventional methods such as prefabricated vertical drains, surcharging, etc. (DE DOT) 3. Our focus is primarily packaging applications. Have not pursued geofoam market. (molder) 4. It has been considered but the cost has been greater than viable alternatives. (MT DOT) 5. Lack of opportunity. We have lightweight fill applications but we use wood chips where they have been less costly than foam. (OR DOT) 6. In areas of very soft soils, DOTD (Department of Transportation and Development) extends the bridge as to reduce the fill height of the approach embankment as much as possible. The settlement is mitigated by long (80+ ft) pile supported approach slabs are then built with decreasing pile lengths from the bridge abutment. In areas where higher fills are acceptable, wick drains are used to accelerate the settlement. To date, geofoam has not been used on a DOTD project-other lightweight aggregates have been used in the past. The technology has not yet been explored mainly due to the conservative approach of government agencies to trying something new compared to the traditional methods of addressing the problem. (LA DOT) 7. Unfamiliarity. Have used in compressible inclusion applications. (consultant) 8. Never heard of geofoam. (SCDOT) 9. There have not been any block geofoam jobs in our immediate trading area. (molder) 10. Not knowing how the cost compares to soil embankment fill. Not knowing how to design. Not knowing what the specifications need to be. Not knowing about the past performance and history. (NV DOT) 11. Not a current market emphasis. (molder) 12. No job was available at our cost. We were too high priced. (molder)

A-13 13. We have placed geofoam on the pre-approved materials list for a lightweight fill. However, the Geotechnical Branch does not specify the type of lightweight fill to be used on a project. (KY DOT) 14. In the situation where we utilized lightweight embankment, the site was a tidal area and there was a good potential for floods which would totally submerge the lightweight embankment. This would have resulted in buoyancy problems if we would have used Geofoam in the embankment. We will be considering geofoam on future projects if lightweight material is needed and if it is cost competitive with other solutions. (GA DOT) 15. As a supplier we have not yet had a job for road construction. (molder) 16. Not familiar with the product. High cost. (ID DOT) 17. Have not had a project in recent past that is applicable. (OH DOT) 18. This is a relatively new technology for us and for our state DOT We are planning to devote additional resources in 2000 toward educating the Texas DOT on this system. While we have not participated in any road embankment projects, we have provided EPS for lightweight fill in under-slab applications. (molder) 19. We have looked/analyzed applications but did not specify due to high cost and lack of geotechnical strength properties of the material. There appears to be no easy way to determine Phi-angle of product, and no values have been published. (WI DOT) 20. Limited knowledge of EPS-block geofoam and limited areas where application of this technology would be beneficial. We believe other options are less expensive but no product representative has ever visited the state. (NE DOT) 21. Expensive-other alternatives cheaper. Pending contract with Colorado DOT includes geofoam. (construction contractor) Synopsis of Replies to A3a: The primary reasons that agencies have not specified, supplied, or installed EPS-block geofoam as a lightweight fill for any road type are perceived high cost and lack of familiarity

A-14 with using EPS-blocks. More conventional treatment methods such as surcharging with prefabricated vertical drains and use of a bridge structure are preferred by some agencies over EPS-block geofoam. Other types of lightweight fills such as wood chips and lightweight aggregates have been used by several of the agencies that responded. Some agencies have not used EPS-block because of concerns with buoyancy. Molders’ primary reasons for not supplying EPS-block is the lack of EPS-block projects in their vicinity, the EPS-block market is not a primary emphasis, or they have not actively pursued this market. The purpose of this report is to provide a comprehensive document that provides both state-of-the-art knowledge and state-of-practice design guidance for engineers. The availability of this report will encourage wider as well as more consistent use of EPS-block geofoam in road embankments. In order to alleviate the high cost perception associated with the use of EPS-block goefoam, Chapter 12 provides an economic analysis of EPS-block geofoam embankments. Question A3b: If the answer to Question A2 was “Yes”, please proceed with the remainder of the questionnaire. A3bi: To help us understand what is the primary benefit of using EPS-block geofoam so that we can develop this aspect to the fullest, what is the primary positive reason for using this material in road applications? Replies to A3bi: 1. To reduce net load of fill/embankment over soft compressible materials. (CT DOT) 2. To lessen the added weight on existing soils or reduce pressure behind existing abutments. (MI DOT) 3. Quick, it works, solves problem. (molder) 4. Lightweight combined with high strength. (WA DOT) 5. Reduce embankment load on weak basement material or slide susceptible soils. (CO DOT) 6. Speed of construction = cost savings, rigid nature. (WY DOT) 7. Lightweight fill and compressible inclusion to reduce lateral earth pressures. (KS DOT)

A-15 8. Reduction in load applied to weak subgrade soils (lightweight fill). (IN DOT) 9. As a superlight weight fill used to reduce settlement and undercut in soft soil deposit. (IL DOT) 10. Weight credit. (MN DOT) 11. Settlement mitigation for buried utilities. (UT DOT) 12. Lightweight fill. (construction contractor) 13. Use as a lightweight fill in landslide treatment, improving stability and eliminating settlement problems of roadway embankments placed over soft soils. (NY DOT) Synopsis of Replies to A3bi: The primary positive reasons for using EPS-block geofoam in road applications indicated by the respondents are (1) its low density minimizes settlement and slope instability, (2) reduced lateral stress behind abutments, (3) fast placement rate which reduces construction time, and (4) reduced stress and consequently settlement over existing utilities. These benefits were included in the economic analysis chapter, Chapter 12. A3bii: To help us understand what aspect(s) of EPS-block geofoam most need improvement, what is the primary negative aspect or issue that you can state about this material in road applications? (Note: Exclude cost of the geofoam material itself.) Replies to A3bii: 1. EPS’s low density makes its use difficult below the water table. Specific dewatering requirements may be needed in such situations. (CT DOT) 2. A good test method for determining compressive strength at 1% strain and examples showing applied loads that are less than that strain. (MI DOT) 3. Lack of knowledge, technical info., lack of experience. (molder) 4. (1) Surface capping requirements (i.e. reinforced concrete), (2) buoyancy-if used in areas with high ground water/flooding, and (3) facing requirements if blocks are placed vertically. (WA DOT)

A-16 5. No other problem but cost. (CO DOT) 6. Cost and availability. Cost/cu. yd. or Cost/cu. m. (WY DOT) 7. Geofoam distributor does not necessarily provide unequivocal data about their product in design phase. (KS DOT) 8. Uniform density and protection from dissolution in gasoline. (IN DOT) 9. Uncertainty regarding long-term durability, performance, flotation, and fire hazard. Placement of EPS blocks requires no standing water in excavation which mandates dewatering. (IL DOT) 10. I was going to say cost and the engineering means nothing without making the costs come out ok. Next I would say insulation or R value contributing to differential icing. Third, the minimum amount of cover needed to eliminate rutting when a concrete cap is not used with respect to both paved and unpaved cases. (MN DOT) 11. Susceptibility to chemical attack by petroleum and petroleum based fuels. (UT DOT) 12. Hydrocarbon attack, durability. (construction contractor) 13. Differential icing on roadway surface and overheating the asphalt concrete pavement section in winter and summer season, respectively, resulting from the insulating nature of geofoam blocks. (NY DOT) Synopsis of Replies to A3bii: In addition to providing a synopsis of the replies, the appropriate chapter number within the report that adresses these negative aspects is provided in parenthesis. The primary negative aspect that the respondents mentioned was susceptibility to hydrocarbon attack (Chapter 2 and 4). The next frequent reply was buoyancy below the water table (Chapter 3, 5, and 6, The respondents also mentioned the following additional negative aspects: difficulty in determining temporary dewatering requirements during construction to prevent buoyancy problems, general lack of knowledge with using EPS-block geofoam, lack of information regarding capping requirements such as the need for a reinforced concrete cap (Chapter 6), lack of information to

A-17 design against differential icing (Chapter 4), lack of information about facing requirements if a vertical embankment is used, density uniformity on blocks obtained at the site (Chapter 9), fire susceptibility (Chapter 2, 8, and 9), material may not be readily available, and lack of a good test method for determining compressive strength (Chapter 2). PART B Question B1: When developing a cost estimate for a design alternative involving EPS-block geofoam for road construction, what one aspect or factor related to the geofoam do you feel the most uncertain or unsure about? This will help us identify those issues requiring the greatest study to help reduce this uncertainty in the future. Replies to B1: 1. Labor cost. (CT DOT) 2. Manufacturing cost (MI DOT) 3. Cost of placement. (molder) 4. Added value as a result of opening the highway to traffic earlier. The use of geofoam over very soft compressible soils may not require the need of pre-fabricated wick drains/surcharges/stage construction/time delays. Using geofoam may result completing the project in significantly less time. What value can we assign to this time savings? (WA DOT) 5. None (CO DOT) 6. Stability (solvents) and flame resistance. (WY DOT) 7. Testing frequency and product quality control (KS DOT) 8. Transportation costs, Installation costs. (consultant) 9. Cost of installation. The contractor over-bids the cost of placing EPS blocks because he doesn’t know how easy it is. (IN DOT) 10. Specific engineering concerns such as compressive strength requirements and block size requirements (molder) 11. Uncertainty regarding the need for dewatering during construction. (IL DOT)

A-18 12. Same response as A3Bii second and third items. I would say insulation or R value contributing to differential icing. The minimum amount of cover needed to eliminate rutting when a concrete cap is not used with respect to both paved and unpaved cases. (MN DOT) 13. The thickness and reinforcing requirements for the reinforced-concrete capping slab. (UT DOT) 14. Long-term settlement in-place. (construction contractor) 15. In treating unstable slopes with geofoam blocks, a proper modeling of EPS blocks in slope stability analyses is currently not available. Other issues include design thickness of subbase material over the geofoam for different climate regions and alternatives to the use of concrete slab for traffic load distribution or petroleum spill protection. (NY DOT) Synopsis of Replies to B1: In addition to providing a synopsis of the replies, the appropriate chapter number within the report that addresses these uncertainties is provided in parentheses. The responses to this question are diverse. Some of the direct cost issues that the respondents indicated include manufacturing cost, transportation cost, and placement cost (Chapter 12). Some construction related items include the uncertainty in predicting temporary dewatering requirements during construction, the value of opening a highway to traffic quicker by using EPS-blocks versus traditional soft ground treatment methods such as surcharging or staged construction, and the uncertainty in the recommended requirements as part of a construction quality control (CQC) and construction quality assurance (CQA) program (Chapter 8 and 9). Some durability issues that were raised include the need for flame-retardant (Chapter 2, 8, and 9) and protection requirements against petroleum hydrocarbons (Chapter 2 and 4). A performance issue that was raised includes prediction of long-term settlement (Chapter 5). Design issues include the minimum amount of cover required to prevent pavement distress and to protect against differential icing if a reinforced concrete cap is not used (Chapter 4). Thickness and reinforcement requirements of a reinforced

A-19 concrete slab if a concrete cap is used (Chapter 6). The issue of block size requirements was also raised (Chapter 2). Question B2: Other than the cost of the geofoam material itself, what item(s) that are related to geofoam (e.g., a reinforced-concrete capping slab, metal inter-block connectors, special site preparation) has your agency or company found to have significant impact on the overall cost of a design alternative involving EPS-block geofoam in road construction? This will help us identify those items that need to be closely evaluated for the purpose of optimization or possibly even elimination in design in order to minimize overall project cost. Replies to B2: 1. Special site preparation. (CT DOT) 2. Concrete cap. (molder) 3. Horizontal capping slab and vertical facing requirements. Seismic requirements (is there a concern for anchoring the geofoam) when placed in a very seismically active area. (WA DOT). 4. Capping and drainage. (CO DOT) 5. Speed of construction, user familiarity. (WY DOT) 6. Uncertainty on part of contractors. (KS DOT) 7. Longevity. (HNTB Corp.) 8. (1) Reinforced concrete cap slab. (2) The contractor over-bids the cost of placing the EPS blocks because he doesn’t know how easy it is. (3) Site preparation for the first lift. (IN DOT) 9. Dewatering the excavation was the most unexpected added cost to the project, since the EPS blocks required no standing water. (IL DOT) 10. The reinforced and or unreinforced concrete cap. (MN DOT) 11. Reinforced concrete slab, fascia wall. (UT DOT) 12. Cost of ground nails to stabilize excavation and eliminate horizontal loading on geofoam wall. (construction contractor)

A-20 13. Special site preparation, especially in areas with a high water table. (NY DOT) Synopsis of Replies to B2: Items found to have a significant impact on the overall cost include reinforced-concrete capping slab, unfamiliarity by construction contractors resulting in over pricing, special site preparation such as temporary dewatering, and facing systems in the case of vertical-faced fills. Other items mentioned include the cost of a permanent drainage system, seismic design, and earth retention to prevent horizontal loading on the EPS-block fill system when used in a side-hill fill application. One aspect that was indicated as reducing cost is the speed of construction when using an EPS-block fill system. These cost issues were included in the economic analysis chapter, Chapter 12. Question B3: Given that there are many factors that influence productivity for placing EPS blocks on a job site, from your experience what is the range of placement costs in dollars-per- cubic-yard or -cubic- metre basis? Replies to B3: 1. Our only experience with EPS has been on a small job (420 CY), below the water table, requiring special site preparation. The unit price given by the contractor (installed) was $75/CY. This price was much higher than for lightweight fill (5,810 CY) at ($10/CY). The lightweight fill was placed over the EPS. (CT DOT) 2. $52.50 - $58.50 per cubic meter. (MI DOT) 3. No idea (molder) 4. I believe placement costs are between 35% and 45% of the unit bid cost. For example-$60 cubic yard unit bid-(knowing the manufacturer’s costs)-$21 to $27 would be the placement costs. 5. No experience (CO DOT) 6. $30-$55/ cu yd (WY DOT) 7. This information is isolated from us. (KS DOT)

A-21 8. Don’t know. (consultant) 9. One contractor bid a job at $66 per cubic yard (material + labor), and another contractor bid at $50/per cubic yard (big variation). (IN DOT) 10. $10-$15, not including mark-up (profit). (IL DOT) 11. Our bid item is for furnished and installed so I do not have a breakdown on this cost. It should be easily under $1.00/cu. Yd. (MN DOT) 12. $65.00/cu m (geofoam without fascia wall), $75.00/cu m (geofoam with fascia wall). (UT DOT) 13. Not sure yet. (construction contractor) 14. Bid price on the only NYSDOT project was $65/cy in 1996. (NY DOT) Synopsis of Replies to B3: A summary of the responses to question B3 is included in Table A.2. Additional cost information is presented in Chapter 12. Table A.2. Summary of EPS-Block Geofoam Prices As shown above, placement prices range from $39.00 to $98.00 per m3. These costs include material, transportation, placement, and contractor profit. The use of a fascia wall adds about $10.00 per m3. One respondent indicated that placement costs are approximately 35% to 45% of the unit bid cost and another respondent indicated that placement costs range from about $13.00 to $20.00 per m3 not including contractor profit. Question B4: Concerning the geofoam specification used on your most recent project: B4i: What was the source (e.g., State or County Department of Transportation Standard/Provisional Specification, in-house specification, provided by EPS molder or distributor)? Replies to B4i: 1. Specification provided by consultant. (CT DOT)

A-22 2. Ours. (MI DOT) 3. DOT(State), manufacturer, engineer. (molder) 4. I adopted a specification developed by the Colorado DOT. (WA DOT) 5. Other DOTs. (CO DOT) 6. WY DOT Geology/Bridge Program. (WY DOT) 7. Specification developed by us. (KSDOT) 8. We developed the specification in-house. (IN DOT) 9. Provided by the geotechnical consultant. (IL DOT). 10. Combination of sources: Dr. Horvath’s book, industry, visiting Norwegian Engineers, other states, and in-house. (MN DOT) 11. Design-build team with consultation with EPS molder and his technical representative. (UT DOT) 12. Colorado DOT Special Provisions. (construction contractor) 13. State DOT, technical papers published by Norwegian researchers, in-house development, and EPS molder. (NY DOT) Synopsis of Replies to B4i: The primary source of a geofoam specification is other state DOT’s specification or an in-house developed specification. However, some of the responses also included consultants and EPS molders. Based on the responses received, some of the state DOTs that have standard/provisional specifications include CO, IN, KS, MI, NY, WA, and WY. A provisional combined material, product, and constructin standard covering EPS-block geofoam in road applications is provided in Appendix C. B4ii: What one item in, or aspect of, the specification were you least satisfied or comfortable with and would like to have more information on or knowledge about to improve? Replies to B4ii:

A-23 1. The construction contract that included the specification was recently awarded and construction activity has not taken place. We have no comment at this time. (CT DOT) 2. Relationship between stress-strain and density. Need more background material. (MI DOT) 3. Recycle content in EPS Block. (molder) 4. Quality control-our specification relied upon manufacturers quality control. Should we require 3rd party lab testing. How may tests for a given volume of geofoam-what to test for/physical sample size used in tests etc. (WA DOT) 5. Density, strength, and creep. (CO DOT) 6. Relied only on supplier certification. (WY DOT) 7. Sampling frequency (KS DOT) 8. Use of polyethylene sheets underneath the EPS. (IN DOT) 9. Specifications should clearly define the method of anti-floatation procedure, in the event water enters the excavation. Also, a minimum amount of dewatering should be specified as incidental, beyond and above which the contractor would be compensated on a cost-plus basis. (IL DOT) 10. Long-term creep performance. (UT DOT) 11. Chemical barrier-an “impermeable geomembrane. (construction contractor) 12. Physical Properties - Water Absorption. (NY DOT) Synopsis of Replies to B4ii: Four items were mentioned more than once in the replies. One concern is relying only on supplier certification for material acceptance. Should third-party certification be required? Third- party certification is addressed in Chapter 9. Another concern is not knowing what types of tests to perform as part of a construction quality control (CQC) and construction quality assurance (CQA) program as well as the frequency of these tests. Test requirements are presented in Chapter 9. The other two concerns mentioned more than once involve the lack of understanding

A-24 between the relationship of density and compressive strength and the long term creep performance of EPS. These two concerns are addressed in Chapter 2 and 9. The following items are indicated once in the replies: physical properties such as water absorption, the need for polyethylene sheets underneath the EPS, chemical barrier requirements over the EPS, and the amount of recycled EPS allowable. Several concerns related to protection of the blocks during construction were also indicated. One concern is not specifying in the specifications the method of antiflotation procedure(s) to use in the event that water enters the excavation. One respondent suggested that a minimum amount of temporary dewatering should be specified as incidental. Question B5: If you ever used EPS-block geofoam from a supplier, or if you are a supplier, who offers third-party certification for the manufactured quality of EPS block: B5i: Do you rely solely on this or do you still do supplemental random sampling and testing of the EPS after it is delivered to the job site? Replies to B5i: 1. Approval of the product may be by certification accepted by the Engineer, written approval of the Engineer, or prior test and or inspection by the Department. (CT DOT) 2. We do random sampling at job site. Density and 1% strain compression tests. (MI DOT) 3. Rely solely on 3rd party certification. (molder) 4. Our specification allowed owner testing-we would only test material delivered to the project, if based on visual inspection (shape/weight appearance), the material appears it would/may not meet specifications. (WA DOT) 5. On-site testing is still done. (CO DOT) 6. Rely on supplier certification. (WY DOT) 7. We do supplemental sampling and testing. (KS DOT) 8. We require manufacturer to submit samples to our laboratory in Materials and Tests Division. Additional on-site sampling and testing at the discretion of the project engineer. (IN DOT)

A-25 9. No third party was involved. The resident engineer conducted random sampling. (IL DOT) 10. We do random supplemental QA testing. (MN DOT) 11. Minimal random sampling. (UT DOT) 12. We would still perform on-site density check. (NY DOT) Synopsis of Replies to B5i: Nine of the twelve responses indicated that random sampling and testing is performed after the EPS is delivered to the job site. Of these, one response indicated that the manufacturer was required to submit samples to the state DOT laboratory. Sampling and testing procedures for EPS blocks are presented in Chapter 9. B5ii: Have you ever had a problem (such as, but not limited to, material not conforming) with third-party certification? If you did experience a problem, describe the problem and offer suggestions to prevent this problem in the future. Replies to B5ii: 1. No experience to date. (CT DOT) 2. Third party reports do not include 1% strain test. We use our own results. (MI DOT) 3. No. (molder) 4. No. (WA DOT) 5. Not to my knowledge. (CO DOT) 6. No. (WY DOT) 7. No. (KS DOT) 8. No. (IN DOT) 9. Not applicable (no third-party). However, there was the problem of the EPS blocks not meeting the weight requirement, but was corrected later. (IL DOT) 10. No problems. (MN DOT) 11. No. (UT DOT)

A-26 12. Yes, density of blocks varied considerably in one particular tractor trailer load with some blocks not meeting density criterion. Contractor had to weigh each block in order to salvage the load. This situation was brought to the attention of the manufacturer. Tighter quality control at the manufacturing plant was exercised. (NY DOT) Synopsis of Replies to B5ii: Nine of the twelve responses indicate that no problems with third-party certification have been experienced. Two of the respondents indicate that problems with third-party certification include the EPS blocks not meeting the density requirements. One response mentioned that the problem with third-party certification is that the compressive stress at 1% strain test results were not provided with the certifications. Third-party certification is addressed in Chapter 9. Question B6: Overall, what one item would you like us to consider or include in the NCHRP project documents that would be of greatest use to you in designing, supplying or installing EPS- block geofoam for road construction? Replies to B6: 1. No comment. (CT DOT) 2. A general design layout drawing for EPS under a roadway built on an Embankment. (MI DOT) 3. Cost factors vs. conventional methods. (molder) 4. Capping and facing requirements. Also look at overall stability modeling (block/rotational???), geofoam strength used in this analyses. (WA DOT) 5. Installation secrets. (WY DOT) 6. Suggested specification, next a design guide approved by FHWA. (KS DOT) 7. Is there a way to eliminate the concrete cap on EPS blocks so as to minimize the overall installation cost? (IN DOT) 8. Cross-sections should be checked for short-term (during construction) and long-term buoyancy of the entire system. (IL DOT)

A-27 9. Amount of cover for the different geofoam densities. (MN DOT) 10. Typical design details and specifications. (UT DOT) 11. Required thickness of subbase material overlying the geofoam to eliminate the phenomena of both differential icing of the roadway pavement surface in the cold season and overheating the pavement section in the warm season. (NY DOT) Synopsis of Replies to B6: In addition to providing a synopsis of the replies, the appropriate chapter number within the report that addresses these items is provided in parenthesis. The predominant item indicated that should be included in the NCHRP report is capping requirements to support stresses generated by traffic loads (Chapter 6), to prevent differential icing and overheating for the various geofoam densities (Chapter 4), and to include alternatives to a reinforced concrete slab (Chapter 4). Other suggested items include general design drawing details (Chapter 10), a design guide that includes slope stability analyses with recommended strength for the EPS (Chapter 5 and 6), facing requirements (Chapter 5), recommended specification (Chapter 9 and Appendix C), installation procedures to include addressing the potential short-term buoyancy problem (Chapter 8), and cost comparisons of the EPS alternative with other soft ground treatment procedures (Chapter 12). Question B7: Do you have any of the following supporting documentation that you think may be helpful to us in achieving the research objectives and that you would be willing to provide (we will contact you for follow up)? Please check all those items that apply: Plans [ ], Specifications [ ], Design reports [ ], Cost estimates and comparisons [ ], Field instrumentation/Performance data [ ], Photographs [ ]. Replies to B7: A summary of the responses to B7 is included in Table A.3. Table A.3. Summary of Replies to Question B7 Synopsis of Replies to B7:

A-28 Ten respondents indicate that they have construction plans, specifications, design reports, cost information, field instrumentation data, or photographs.

TABLE A.1 PROJ 24-11.doc AR MI CO MN CT MT DE NE GA NV HI NY IA OH ID OR IL SC IN UT KS WA KY WI LA WY A-29

TABLE A.2 PROJ 24-11.doc STATE YEAR QUANTITY m3 (yd3) Bid Price in U.S. $/ m3 ($/yd3) CT 1999 321.1 (420) 98.00 (75.00) IN 1995 4,707.6 (6,157) 65.00 – 87.00 (50.00-66.00) MI - - 52.50 – 58.50 (40.15-44.73) NY 1996 3,115.7 (4,075) 85.00 (65.00) UT - - 65.00 (Note 1) (50.00) UT - - 75.00 (Note 2) (57.00) WY - - 39.00 – 72.00 (30.00-55.00) Note 1: Without fascia wall. Note 2: With fascia wall. A-30

TABLE A.3 PROJ 24-11.doc Agency or Company Plans Specifications Design Reports Cost Estimates and Comparisons Field Instrumentation /Performance Data Photographs CTDOT X MIDOT X X MOLDER X X X WADOT X X X X X WYDOT X X X X X KSDOT X X INDOT X X X X X ILDOT X X X X X UTDOT X X X X X X NYDOT X X X X X A-31