Chapter Three - Materials for Bridge Constructions

Abstract

The traditional building materials for bridges are stone, timber and steel, and concrete. Timber and stone can be considered natural materials as they are directly obtained from nature and are used unprocessed in the first period. Bricks were also used but generally included as a subgroup of the stone bridges. After a long period of time, many of the stone bridges are still preserved due to the durable material. As a contrast, few timber bridges still served because their material degrades easily and rapidly due to fire, water, flood, etc. In this period, bridges develop mainly on the basis of the materials but not bridge technology because the materials (such as stones and wood) played an important role in the bridge configuration. The other two, steel and concrete, are artificial, as the raw materials taken from nature need more or less complex processing that changes their physical properties. The appearance of iron and concrete bridges can be considered as the second period and also is the beginning of the modern bridge engineering. In most cases, modern bridges mean the bridges built with steel and concrete, or other new materials. In addition, composite materials formed by fibers of high strength materials are also being used nowadays, not only for new bridges but also for strengthening the existing bridges.