CONCRETE FOR MAJOR INFRASTRUCTURAL LINKS

Development of the concrete requirements through the 20th century for major infrastructural links has been extensive. A comparison of the concrete composition for major structural links including bridges and tunnels with the modern international codes and standards shows that we today have specifications that ensure long service life of our structures. All over the world there are many concrete structures which are in outstandingly good condition compared to their age, but we have also examples of structures that within a few years deteriorated to a poor condition, but then well maintained and lasted for a further many years. This information can be used for setting up the requirements not only to the concrete but also to the structural design it self – since today we want not only high performance concrete but also high performance structures. There is a long tradition for setting up concrete requirements when the structures are executed which culminated when setting up the specifications for the Great Belt Link. To understand the modern concrete requirements and specifications, it is necessary to look back in time on the concrete development and exploring the concrete specifications. This paper will be focused on the material requirements in the concrete codes and descriptions for construction of major bridge and tunnel structures which played an important role in the development of the concrete used for these structures. Additional aspects regarding durability and design will be discussed. The paper will not be a complete overview but will point out some of the highlights and experience from the bridge design achieved by COWI as leading designer in major links all over the world.

• INTRODUCTION

• EARLY CODES, STANDARDS AND REQUIREMENTS

• MAJOR CONCRETE STRUCTURES

• MODERN REQUIREMENTS

• DURABILITY ASPECTS

• REFERENCES