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1 Summary The Innovative Bridge Research and Construction (IBRC) program, cre- ated by an act of Congress in 1998, provided grants to state transportation departments as incentives for use of innovative materials and technologies in the construction and repair of highway bridges. The program awarded $128.7 million to approximately 400 projects from 1999 to 2005. Materials used included fiber-reinforced polymer (FRP) composites, high-performance concrete (HPC), high-performance steel (HPS), and corrosion-resistant reinforcing bar (rebar). Projects also demonstrated accelerated bridge con- struction (ABC) techniques. As directed by Congress, the U.S. Department of Transportation ( USDOT) commissioned the Transportation Research Board (TRB) to study the performance of the bridges that received funding in the IBRC program. TRB formed a committee charged with four tasks: analyze the performance of bridges that received funding in meeting the programâs goals; analyze the utility of the materials and technologies used in IBRC projects in meet- ing needs for a sustainable and low life-cycle cost transportation system; recommend to Congress how life-cycle costs of bridges could be reduced through use of innovative technologies; and identify research needed to reduce bridge life-cycle costs. To respond to the charge, the committee examined how the experi- ence of the IBRC projects affected highway agency practices, in particular, whether the technologies used in the statesâ IBRC projects were incorpo- rated in regular practice, and examined data on the performance of the IBRC bridges. The principal sources of information were interviews with
2 PERFORMANCE OF BRIDGES the staffs of 10 state transportation agencies that participated in the pro- gram and records of the IBRC projects. The first three chapters of the report summarize the committeeâs con- clusions on the extent to which the IBRC projects met the goals of the pro- gram, the utility of the technologies, and opportunities to reduce life-cycle costs of bridges. The final chapter presents recommendations. PERFORMANCE OF THE IBRC PROJECTS IN MEETING THE GOALS OF THE PROGRAM The projects completed under the IBRC program contributed to the fulfill- ment of at least five of the seven statutory goals of the program (see Box 1-1). The technologies used will reduce life-cycle costs. The data available on the IBRC projects does not contain the information needed to compare life-cycle costs of alternative technologies. Information is available from other sources on effects of IBRC technologies on life-cycle cost, but the evaluation record is incomplete, and economic comparisons are especially scarce. Nevertheless, based on the existing evidence, including information on the physical properties of the innovative materials used in IBRC proj- ects, published cost comparisons, and acceptance of several of the IBRC technologies in state highway programs, the committee concludes that it is likely that the program contributed to the reduction of costs. The IBRC technologies can reduce construction time and traffic con- gestion by reducing either the duration of construction or the frequency of construction and maintenance. Safety is improved particularly by shorten- ing the frequency and duration of work zones, which reduces the risk of casualties to the public and to workers. Materials demonstrated in IBRC projects that can help bridges withstand natural disasters include HPC, HPS, and externally bonded FRP reinforcement. The experience that high- way agencies gained in IBRC projects was a stimulus for the development of standards and specifications for some of the new technologies. Techniques to separate vehicles and pedestrians from rail traffic were not the primary objective of any IBRC project, although reducing construction cost and du- ration facilitates the elimination of grade crossings. Similarly, development of nondestructive evaluation techniques was not the primary focus of any project, but several projects included instrumentation to allow condition monitoring. UTILITY OF THE IBRC TECHNOLOGIES Certain applications in every category of IBRC technologies (HPC and other advanced concrete materials, FRP composites, corrosion control tech- nologies, HPS, and ABC) showed high utility for reducing bridge life-cycle
SUMMARY 3 costs. Several have achieved general acceptance in state highway bridge programs (including HPC, HPS, stainless steel rebar, and externally bonded FRP reinforcement). Others (including ABC and monitoring technology) could produce much greater savings if used more widely in appropriate applications. Some of the IBRC technologies (for example, FRP deck and superstructure elements) will require further development and evaluation before their correct use and full potential can be determined. OPPORTUNITIES TO REDUCE LIFE-CYCLE COSTS OF BRIDGES THROUGH INNOVATION The following conclusions concern the value of federal incentives for innova- tion, the role of highway agency practices in fostering cost-saving inno- vation, and specific technological opportunities. Importance of Federal Incentives as Stimulus for Innovation in Highway Bridges The funds provided by the IBRC program mitigated the risk of innovation and motivated use of new technologies. The greatest impact was through the incentive to apply technologies that were already developed and of proven benefit but not yet standard practice (advanced concrete materials, externally bonded FRP reinforcement, HPS, and ABC). The program was less successful at increasing application of technologies that were at earlier stages of development. The program lacked features that would be required to advance earlier-stage technologies toward implementation, in particular, planning to define and focus resources on objectives and a provision for monitoring and evaluation. A new federal incentive grant program for innovative bridge technology could continue the success of IBRC in accelerating the adoption of proven technologies and also contribute to advancing less developed technologies by supporting state highway agency bridge projects that were coordinated as elements of research and evaluation studies. Importance of Management and Evaluation Practices That Support Innovation The methods that a highway agency uses to design, construct, and main- tain bridges and manage its bridge network are the primary factors that determine success in controlling costs and maximizing the public benefits of bridge investments. Life-cycle cost analysis is necessary to evaluate technol- ogy that extends the life of a structure or reduces the frequency of repair. A bridge management system that identifies maintenance and rehabilitation
4 PERFORMANCE OF BRIDGES needs will highlight the value of cost-saving innovations for repairs or for avoiding the need for repairs. A new federal innovation incentive grant program could contribute to advancing highway management practices by providing data on the performance of alternative technologies and through support for highway agency trials of state-of-the-art management systems and evaluation methods. Specific Technology Opportunities The committee reviewed the status of the technologies demonstrated in the IBRC projects and innovations that have emerged since the program to identify opportunities to reduce life-cycle costs and improve bridge per- formance. These opportunities are listed in the final chapter of the report. RECOMMENDATIONS The recommendations of the committee concern three topics: a new fed- eral program to provide incentives for innovation in bridge construction, research needs to develop and evaluate innovative approaches to reducing bridge costs, and other actions to encourage innovation. New Federal Program to Provide Incentives for Innovation in Bridge Construction Congress should create a new federal bridge innovation incentive program, administered by the Federal Highway Administration (FHWA), to advance the development and application of technologies for improving bridge performance and reducing life-cycle costs. The new federal program can be modeled on IBRC but should include the following features in order to improve on the results of the earlier program: ⢠Program plan: The program should be guided by a plan that defines the objectives, allocates funds in accord with the objectives, and specifies procedures for selecting projects. FHWA should develop the plan in consultation with the state highway agencies. ⢠Definition of objectives: Objectives should be defined with respect to (1) the technologies to be developed, (2) improvements in bridge performance to be obtained with each technology, and (3) the contribution of the program to advancing each technology. The objectives may include expanding use of proven technologies and developing or evaluating earlier stage technologies. ⢠Recordkeeping: FHWA should maintain comprehensive infor- mation on each grant awarded, through project completion and
SUMMARY 5 follow-up evaluation. Changes in the location, scope, or technolo- gies involved in a project should be recorded. ⢠Dissemination: FHWA should arrange for dissemination of infor- mation on projects under way, assessments of completed projects, and monitoring results. ⢠Monitoring performance of technologies: The program should include funding and requirements for monitoring. Monitoring should be on two tracks: Every project should be subject to a minimum standardized monitoring requirement, and projects that have the objective of development or evaluation should have addi- tional requirements, including a research design that specifies data collection. ⢠Emphasis areas: Emphasis areas for projects should be determined by the federalâstate consultative planning process previously rec- ommended. Emphasis areas recommended for consideration are listed in Chapter 5. Research Needs USDOT and the state departments of transportation should consider spon- soring research to develop and evaluate innovative approaches to reducing the costs of highway bridges, with the following objectives: ⢠Long-term monitoring of durability, performance, and costs of materials and technologies. Standard procedures for inspection of the materials could be developed in conjunction with monitoring studies. ⢠Optimized designs and standardization for advanced materials to maximize the cost savings attained. ⢠Optimized design for ABC that takes full advantage of the econo- mies attainable from prefabrication of bridge elements and systems. ⢠Development and validation of models for projecting service life and deterioration rates. ⢠New nondestructive bridge evaluation technologies and techniques. ⢠Development of new advanced materials and use of new materials in bridge construction. ⢠A program of research and technology transfer to determine the potential for greater use of and benefit from FRP materials in bridge construction. Such a program is outlined in Chapter 5. ⢠Methods of maintaining and updating existing infrastructure to accommodate truck platooning (operation of two or more trucks in a convoy with close spacing maintained by an advanced driver assistance system) and other upcoming transportation technologies.
6 PERFORMANCE OF BRIDGES Other Actions to Encourage Innovation ⢠Professional interchange: The state highway agencies should recog- nize the essential role of professional interactions for disseminating technical advances, support the establishment of opportunities for technical exchange, and support the participation of their engineers in these activities. ⢠Existing federal highway innovation programs: Congress should continue to provide funding and direction for the existing innova- tion programs administered by the FHWA Center for Accelerating Innovation. These programs have accelerated the adoption of new technology.
