Henry G. Russell, Henry G. Russell, Inc.
The Economical Solution for Durable Bridges and Transportation Structures was the theme for the second International Symposium on High Performance Concrete held September 25-27, 2000 in Orlando, Florida. With an attendance of over 1500, the symposium brought together experts from the United States and around the world to discuss the most recent applications and developments in high performance concrete. The symposium was sponsored by the Precast/Prestressed Concrete Institute (PCI), the Federal Highway Administration (FHWA), and the Fédération Internationale du Béton (fib) and was held in conjunction with PCI’s 46th Annual Convention and Exhibition.
The symposium featured nine sessions covering General History, Marketing, and Implementation; Materials and Mix Design; Laboratory Research and Future Direction; Quality Concepts, Fabrication, and Transportation; Construction Techniques; Structural Design and Concepts; Structural Performance and Code Requirements; FHWA Showcase Projects and Case Studies; and fib’s Approach to High Performance Concrete Structures.
In his opening remarks, Tony Kane, Executive Director of FHWA presented his top ten list of changes for the next 100 years. Number one on his list was high performance concrete in bridges with a projected service life of 100 years. He mentioned that 30 states have now used HPC in some of their structures and that, over the next 50 years, there will be major reconstruction of the urban infrastructure with the need for innovative construction methods using longer-lasting materials. Coupled with this is the need to construct quickly so as to minimize the impact to the traveling public.
Technical Sessions
In the technical sessions, a wide range of topics was presented. With over 400 attendees from 42 foreign countries, there was ample opportunity to learn about developments from outside the USA. In a session devoted to fib’s approach, one speaker emphasized that new codes should focus not only on design for strength and serviceability but also on design for durability. Another speaker emphasized that service life should be reliability based, in the same way that loads are currently treated. This approach is already being used for major European bridges.
There were presentations about applications of HPC in Belgium, Cuba, Denmark, France, Norway, and Thailand. Within the USA, there were presentations on bridge applications in Delaware, Louisiana, North Carolina, Virginia, and Washington.
Structural design and research was featured with a wide range of topics including shear capacity, composite action, flexural behavior, design optimization, rotational capacity of members, bond, and code applications.
Durability and chloride penetration were popular topics and a major worldwide concern. Attendees were able to learn about corrosion modeling, the effects of concrete constituent materials on concrete durability, techniques to measure permeability, use of the maturity method, effects of curing on concrete properties, and high performance grouts for post-tensioned bridges.
Presentations on construction issues dealt with topics such as self-compacting concretes, repair and strengthening techniques, bridge deck overlays, cracking in prestressed concrete girders, and fiber reinforced concrete.
The symposium clearly illustrated the growing use and interest in HPC on a worldwide basis and the need to obtain a better understanding of its behavior through research. The constant evolution of new materials will continue to present opportunities for the future.
Further Information
Copies of the proceedings of the symposium, as well as copies of the proceedings from the first symposium, held in New Orleans in 1997, are available from PCI at 312-786-0300; (fax) 312-786-0353; email [email protected]. Both proceedings contain over 800 pages and a wealth of information.