The power of prestressing

The idea of prestressing—a product of the twentieth century—has announced the single most significant new direction in structural engineering of any period in history. It put into the hands of the designer an ability to control structural behaviour and, at the same time, it enabled the designer—or forced the designer—to think more deeply about the construction. Moreover, the idea of prestressing opened up new possibilities for a form that influences the general culture. To focus on that fact, and to narrow the scope, the paper will consider bridges only, even though prestressing has broad applications to all kinds of buildings. However, the idea of prestressing arose out of bridge design, and its most impressive forms, from a purely engineering viewpoint, have appeared in bridges.