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The early history of concrete follows that of cement. As cement properties improved so did the strength and application of concrete. Being strong in compression, it was best used in load bearing situations, such as foundations and load bearing walls, where tension stresses were not developed. This changed with the advent of reinforced concrete in the mid 19th century.
As early as the 1830s it was suggested that iron tie bars could be embedded into a concrete section to carry tension forces and by the 1870s reinforced concrete was being used in bridge construction and other structures. For buildings, interest in its use was heightened by a recognition of the fire resistant properties of concrete.
An important stage in the 1920s was the introduction of prestressed concrete. By using tensioned steel within concrete it can be put into compression before it carries its self weight and applied loading. When these loads are applied, the concrete can easily resist further compression while the induced tension simply relieves the compression forced in the tension zone. This makes better use of the concrete´s compressive strength so a structural member will be stronger and possibly have a smaller cross section than that required for reinforced concrete.
The development and use of reinforced concrete were very rapid throughout the 20th century. As cement compositions changed the types of concrete also expanded from low to very high strength, lightweight to heavyweight etc. Such is the diversity of concrete types that a suitable concrete can now be found for almost all structural applications.
Acknowledgement: The Concrete Society
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