Chapter 1: Introduction

The concept of prestressing, an idea born in the 20th century, is the single most significant new direction in structural engineering in any period in history (Billington, 1976). It put into the hands of designers the ability to control structural behaviour, and at the same time enabled – or forced – them to think more deeply about the structure itself. Moreover, the application of prestressing opened up new possibilities regarding the form of structures, and this has had an influence on general culture. The idea of prestressing arose out of bridge design, and the most impressive structural forms involving prestressing, from a purely engineering viewpoint, are evident in bridges.