Basile G. Rabbat, National Concrete Bridge Council
During the last 15 years, research performed on high performance concrete (HPC) has led to the construction of a number of HPC bridges in the United States. In the late 1980s, the Strategic Highway Research Program identified HPC as one of seven key technologies to be considered for further development and implementation. In 1991, ISTEA provided funding through FHWA to assist states in building HPC bridges and to showcase the results. Under TEA-21, the Innovative Bridge Research and Construction Program (IBRC) was instituted to encourage innovation and improve the long-term performance of bridges through the use of HPC and other materials. Success stories and lessons learned from design and construction of many of the HPC bridges were reported in previous issues of this newsletter.*
In a memorandum dated May 12, 1997, FHWA Executive Director Anthony R. Kane stated: “A goal of the AASHTO Lead States and of the FHWA HPC Technology Delivery Team is the completion of at least one HPC bridge project in every state by the year 2002.” As of this date, nearly 50 bridges in 30 states have been built under ISTEA’s FHWA showcases or TEA-21’s IBRC program.
Bridges are an integral part of our highway system. They are essential for the movement of people and goods and for our nation’s economic growth and prosperity. The most promising materials and construction methods must be selected to extend the life of bridges. In the January 31, 2000, issue of ENR, FHWA Administrator Kenneth Wykle challenged industry and academia to design and build bridges to achieve 100-year useful lives. Wykle saw advances in HPC as a way to get there.
Realizing the need to coordinate the HPC experiences learned, and to respond to Wykle’s challenge, industry initiated the development of a strategic plan for HPC bridges. Representatives from FHWA, state highway agencies, consulting engineering firms, academia, and industry met in a focus group in November 2000. They brainstormed over the advantages, weaknesses, opportunities, and threats to HPC for bridges. The group identified several critical issues that need to be addressed: lack of understanding on the use of HPC, lack of technology transfer mechanisms, inadequate education of engineers, and little training in life-cycle cost methods for bridges. The focus group concluded its meeting by agreeing that a detailed plan for cooperative research, implementation, and technology transfer for HPC bridges was needed to enable all bridge owners to benefit from this technology.
To address this need, the National Concrete Bridge Council (NCBC) is developing a white paper that will outline a strategy to tackle the focus group’s critical issues. Development of a detailed action plan with participation of all stakeholders will follow the publication of the white paper. The action plan will identify the scope and estimated costs of individual research and development projects and technology transfer programs.
HPC holds great promise for improving the condition of our highway bridge inventory and for maintaining the momentum for economic growth and welfare of our nation. The speed of construction with precast HPC has helped overcome many congestion and work zone safety issues. New HPC decks have exhibited reduced cracking and will, undoubtedly, extend the service lives of bridges, with minimal maintenance. Valuable information, specifications, materials, and methods have been developed within the last decade. The white paper and action plan will provide a framework and cost estimate for gathering this information, synthesizing it, supplementing it with needed research, and for training designers, specification writers, constructors, inspectors, and quality control supervisors in implementing HPC technology.
Further Information
For more details or comments, contact the author at: [email protected].