"Design and Construction of Segmental Concrete Bridges for Service Life of 100 to 150 Years"

Editorial by Cliff Freyermuth, Manager, ASBI

The title of this editorial is the title of a presentation by Steen Rostam* at the 2005 ASBI Convention. This paper is included with this edition of the ASBI newsletter. Contrary to assertions by some U.S. interests, this paper indicates: “The challenge of providing factual service life design documenting 100 to 150 or more years design life can be achieved and at times this is surprisingly easy”.

To encourage your detailed review and consideration of this information, following is a partial quotation of the conclusion of this paper:

“The complexity of designing well performing, low maintenance and long-lived concrete structures has been presented in this paper. It highlights the multidisciplinary set of problems to be solved by the designer in order to ensure truly long service life with minimal maintenance of concrete structures.

However, the descriptions of the individual measures needed to achieve this goal have also been shown to be relatively simple - in most cases sur-prisingly simple - and using well-known methods, materials and technology. The real challenge is in fact twofold:
1. The owner shall formulate performance requirements to the structure in a format that can be translated into a quantified design basis, taking the long term effects or consequences, including acceptable needs for maintenance, into account technically as well as in the economic evaluations.
2. The designer and the contractor need to combine readily available knowledge from design, construction, materials technology and deterioration mechanisms into an integral solution adapted to the individual structure in its foreseen environment.

Our daily terminology using “durable concrete” and discussing “High Performance Concrete” is misleading. In fact, no one cares very much about high performance concrete (except maybe the cement, concrete and admixture producers) but what we all need is High Performance Concrete Structures, and that is a completely different challenge, as highlighted in this paper.”

*Chief Engineer, MSc PhD, COWI A/S, Denmark. Chairman fib Commission 5 “Structural Service Life Aspects”