Development of modern prestressed concrete bridges in Japan

Abstract

Prestressed concrete (PC) is being used all over the world in the construction of bridge structures. In Japan, the application of PC was first introduced in the 1950s, and since then, the construction of PC bridges has grown dramatically. This is largely due to several advantages such as lower initial and life-cycle cost compared to steel bridges, and superior characteristics concerning economical and aesthetical aspects compared to reinforced concrete bridges. However, many PC bridges have been deteriorating even before their designed service-life due to corrosion and other environmental effects. Therefore, the durability has become a particular concern and should be seriously considered in the design and construction of PC bridges. In Japan, a number of innovative techniques have been developed to enhance both the structural performance and the durability of PC bridges. These include the development of new materials such as pre-grouted internal tendon, high-strength concrete and structural systems such as external prestressing, highly eccentric external tendons, extradosed prestressing and corrugated steel web. This paper presents an overview of such innovated technologies of PC bridges including a brief detail of their development and background as well as their applications in the actual construction projects