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NCHRP Project 12-102 15 C H A P T E R 3 Literature Review and Industry Questionnaire 3.1 Literature Review The literature search was divided into two categories. Berger ABAM and the University of Washington were tasked with investigating seismic related ABC technologies. CME completed the investigation of non-seismic ABC technologies. The literature review was conducted to identify applicable research and owner and industry experiences. This project aims to synthesize previous work while improving design and construction. Current research by universities and state agencies in the area of ABC is extensive. Areas of research that were investigated consist of: ⢠Materials (e.g., UHPC) ⢠Prefabricated decks (e.g., full-depth precast panels) ⢠Prefabricated decked beams ⢠Precast dubstructure (e.g. precast wall abutments) ⢠Substructure connections (e.g., pile to precast footing connection) ⢠Superstructure connections (e.g., transverse and longitudinal joints between deck panels and decked beam elements) ⢠SPMT systems ⢠Lateral slide systems ⢠Seismic connections and details ⢠Lessons learned from demonstration projects and other ABC projects A significant amount of research was found related to proprietary systems, such as fiber-reinforced polymer deck systems and grout-filled mechanical splice couplers. It is the opinion of the team that proprietary items would not generally be included in the ABC Guide Specifications. Some of the proprietary items such as grouted sleeve couplers were included since multiple manufactures can provide equal performance, thereby eliminating the proprietary nature of these products. Three main approaches were used for the literature searches. The TRB TRID database was searched. Conference proceedings were investigated. The team examined every state DOT website to investigate if something was studied locally and not posted in the TRID database. A questionnaire was also sent out to each state DOT. Each state was asked to submit any research that they had completed. The literature search was not limited to the United States. The database search uncovered a number of international research projects from Brazil (Araújo and El Debs, 2005 and Barros and Giongo, 2013), Canada (Au, et al., 2011), South Korea (Shim, et al., 2001), Japan (Niswsco, (undated) and Aida, et al., 2005), Sweden (Harryson, 2003), France (Parant, et al., 2006), Australia (Mashal, et al., 2014),
NCHRP Project 12-102 16 Netherlands (Riva, 2006), England (Lai, 2010 and White, 2014), and Malaysia (Alias, et al., 2013). Finding international research can be difficult due to the different languages, which make internet searches impractical. This does not mean that the team has not looked into other international work. Michael Culmo, the principal investigator of this project, has attended international bridge conferences in the last few years. They included: ⢠ABC Workshop in Stockholm, Sweden: This workshop was specific to ABC. It included participation from all northern European countries. All countries have experimented with ABC, but only on a case-by-case basis. Michael Culmo gave a presentation on the use of ABC in the United States. Engineers from most European countries also presented on the use of ABC in their countries. ⢠Australia Short-Span Bridge Conference in Sydney, Australia: This conference concentrated on county type bridges in Australia, where prefabrication is used to a certain extent. Michael Culmo gave a presentation on the use of ABC for short-span bridges. ⢠International Association for Bridge Management and Safety Biennial Bridge Conference in Stressa, Italy: This is a true international bridge conference with participants from all over the world. ⢠Bridges 2015 Conference in Manchester England: This is an annual conference for bridge owners and consultants in the UK. Michael Culmo gave a presentation on the use of ABC in the US and how it could be applied to the UK. The conclusion that can be drawn from these conferences is that the US was much more invested in ABC and has progressed the technologies further than other countries. Each country has used ABC, but not on a systematic basis. Another interesting note was the lack of bridge deck replacement needs across the globe. Many countries use high quality waterproofing systems combined with asphalt overlays. They expect the bridge deck to last for the life of the bridge (similar to segmental bridges in the United States), therefore the need for prefabricated deck replacements is very limited. CME has also engaged Professor Campbell Middleton from the University of Cambridge, Department of Civil Engineering in Cambridge, England. Professor Middleton manages a group called the Bridge Ownerâs Forum in the UK. This group is similar to the AASHTO Bridge Subcommittee. The forum looks to improve communication among the UK bridge owners, leading to consistency in bridge practice. Professor Middleton has indicated that the use of ABC in the UK is sporadic, but they are interested in building on the work in the United States. This engagement of Professor Middleton led to the invitation to speak at the Bridges 2015 Conference in Manchester, England (noted above). There has not been as much research on seismic ABC technologies in the past. More recently, there has been a wave of new ABC seismic research. The team is aware of a significant amount of other on- going work. We plan to track this work, as some of it will inevitably be included in this project or future editions of the guide specifications. In general, seismic research for ABC has concentrated on connections between precast elements. This is not surprising, since seismic bridge design focuses on connection performance. The work found can be grouped into the following major categories: ⢠Bar Coupler Connections ⢠Grouted Duct Connections ⢠Socket Connections ⢠Pocket Connections ⢠Integral Connections
NCHRP Project 12-102 17 One of the difficulties with seismic specifications is that there are currently two seismic design specifications in use today. They are the AASHTO LRFD Bridge Design Specifications, based upon force design, and the AASHTO Guide Specifications for LRFD Seismic Bridge Design, based upon the displacement method. Both documents are in use by a number of states. Much of the past research work focused on the force design approach. On-going work is looking into the new displacement-based method. The project team has taken the approach of reporting on and including guide specifications related to both. Another difficulty associated with addressing the seismic specification aspects of this work is the nature of its emerging technologies. Advancements in materials, components, and seismic resisting systems are underway, and are still being evaluated and developed for implementation on bridge projects. The development and implementation goals of these advancing technologies are primarily to enhance seismic performance of the bridge and not specifically to accelerate bridge construction, though some may be utilized as ABC with proper detailing. An example of these technologies is self-centering design. These technologies are still under development and have not been fully vetted by the AASHTO Subcommittee on Bridges and Structures, therefore, they were not included in the guide specifications at this time. Chapter 3 contains the results of our searches. The team is aware of other current ABC research that is in progress. This is not an issue since this project is essentially a synthesis of past work. Once the framework for the guide specifications is complete, additional technologies can be added at a later dates by the AASHTO Construction Technical Committee (T-4). There has been a plethora of research related to ABC. Some of the work dates back decades, which is a testament to the long history of ABC and prefabrication. Reference information for all of the relevant research found is included in this report. Over 150 sources have been identified. 3.2 Questionnaire A questionnaire was developed and sent to each State Department of Transportation. The goals of the questionnaire were to uncover local research that may or may not have been included in the typical search databases, identify any completed and current work, and to get a compilation of the type of ABC work that is being used throughout the country. As expected, a significant amount of ABC work has been completed or is underway. Results were obtained from 28 of 50 states. A larger response is desirable, however the data submitted by the 28 states is valuable. The 28 states that did respond, represent most of the states that have the most active ABC programs. The majority of the remaining states that did not respond are not prolific users of ABC technologies. A review of the results indicate that there are literally dozens of ABC technologies in use in the United States at this time. Virtually all types of concrete structures have been built using precast concrete including but not limited to full-depth decks, abutments, walls, piers, footings, and barriers. Modular superstructure elements are also commonly used including, but not limited to deck bulb Tees, Double Tees, and concrete topped steel girders. Various types of bridge systems have been used throughout the country, with SPMT installations and Lateral Slide Installations being the most popular. The team has strived to incorporate provisions for all the technologies in use. Where research was available, specific provisions were written. Where research was lacking, general provisions were developed.
NCHRP Project 12-102 18 The team has compiled the results of the questionnaire and included them in Appendix A.
