SECTION 3
Data Collection Methods
3.1 Literature Review
The research team reviewed the literature assessing the impacts of UHPC-C in the United States and abroad, including case studies of state and local deployments and assessments of the economic impacts of UHPC-C adoption. The review focused primarily on finding literature and data sources to complement interview data collection efforts. These sources helped inform the quantifications of the socioeconomic impact of UHPC-C. All sources used are cited throughout this report.
Data from the National Bridge Inventory (NBI) maintained by FHWA grounded subject matter experts’ (SMEs’) estimates about future adoption; from that information, the evaluation estimated the number of future bridge construction projects that will use UHPC-C. The NBI is a database with 100 fields covering almost 700,000 bridges across the United States. Its data fields describe bridge locations and characteristics, details on the most recent inspections with condition ratings on various bridge components, and other measurements included in the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation’s Bridges (FHWA 1995). The NBI was used to identify bridges that could be replaced with bridges constructed using ABC methods and UHPC-C and to quantify project-level benefits, such as avoided traffic hours, on the basis of accelerated field construction time.
Additional data sources were used to retrieve costs for bridge construction and maintenance activities. The evaluation used 2021 data from the ABC Project and Research database maintained by the Accelerated Bridge Construction University Transportation Center at Florida International University (FIU) to obtain construction cost data, including unit costs for different types of concrete. The Florida Department of Transportation’s (DOT’s) innovation web page (2021) contains case studies on uses of UHPC that provided additional data on total project costs. Maintenance costs were collected from the Open Book Contracts database managed by the New York State Office of the State Comptroller (2021) and verified through the report Life-Cycle Cost Analysis of Reinforced Concrete Bridges Rehabilitated with CFRP (Smith 2015). The types and frequency of state DOT bridge maintenance and rehabilitation activities were obtained from the FHWA Bridge Preservation Guide (2018c).
3.2 Interviews
The research team identified and interviewed SMEs from six stakeholder groups to capture diverse perspectives on UHPC-C. See Table 3-1 for a list of stakeholder groups with descriptions of their roles in the bridge delivery process and in UHPC-C implementation. The table also includes examples of the types of companies and organizations targeted for interviews, as well as the number of SMEs who completed interviews. Additional details about the bridge delivery process are provided in the Appendix.
Table 3-1. Populations of subject matter experts targeted for data collection.
Stakeholder Group | Role in Bridge Delivery | Role in UHPC-C Implementation | Example Target Companies/Organizations | Number Interviewed |
---|---|---|---|---|
Owner Agencies | Determine project criteria; select design company, general contractor, and inspection company | Include UHPC-C in project criteria; select designers, contractors,and inspectors with needed skills | Port authorities (e.g., New York/New Jersey), large local agencies (e.g., Los Angeles County), state DOTs (e.g., New York DOT, Iowa DOT) | 4 |
Engineering Design Companies | Design bridge fitting criteria; may also be general contractor | Have skills or choose to develop capacity to design using UHPC-C | TYLin, Stantec, Atkins, HDR, URS AECOM, Tetra Tech, Bergmann Associates | 4 |
UHPC Supplie rs | Provide UHPC fitting project criteria; company selected by contractor or specified by owner agency | Previously consisted of single proprietary mix (Ductal); as of 2021, there were four U.S. suppliers | LafargeHolcim (Ductal), Steelike,Cor-Tuf, ceEntek, Dura (Malaysia) | 3 |
PBE Suppliers | Provide precast concrete fitting project criteria; company selected by contractor or owner agency | Extensively influence UHPC-C use through PBE applications | Kistner Concrete Products, Inc.; Concrete Industries, Inc.; Harper Precast; Fort Miller | 1 |
Research and Academia | Research and test improved bridge materials, design, and delivery methods; partner with owner agency | Develop new UHPC generics | Research centers at state DOTs and Montana State, Florida International, Washington State, and Iowa State Universities | 3 |
Industry Trade Associations | Represent other stakeholder groups listed in table | Have committees dedicated to ABC methods, PBEs, UHPC, or any combination of these | ASCE, American Segmental Bridge Institute, National Precast Concrete Association, American Society of Concrete Contractors, American Concrete Institute, ASTM | 1 |
NOTE: ABC = accelerated bridge construction; DOT = department of transportation; PBE = prefabricated bridge element; UHPC = ultra-high performance concrete; UHPC-C = UHPC connections.
The research team contacted SMEs via e-mail to request a 1-hour telephone or videoconference interview. The e-mail described the aims of the study and the reasoning for reaching out to that SME. The research team followed up twice with each nonresponding SME. Before the interview, all SMEs received a targeted interview guide for their stakeholder group to allow them time to consider their responses. One provided written responses in lieu of a phone interview because the COVID-19 pandemic disrupted the SME’s availability.
The research team contacted 43 SMEs and completed interviews with 16; several of them map to user groups within the bridge delivery process and sit on committees from relevant industry trade associations. Respondents provided information reflecting perspectives across all relevant stakeholder groups. However, the team did not identify any willing interview respondents among general contractors, conventional concrete suppliers, or inspection and materials-testing companies. Interviewed SMEs were evenly split among owner agencies; engineering design companies; UHPC or PBE suppliers; and research, academia, or trade associations. SMEs were interviewed from organizations located in 10 U.S. states: Arizona, Connecticut, Florida, Illinois, Iowa, Montana, New York, Texas, Utah, and Virginia. One SME located in Malaysia was also interviewed.