Reinforced concrete is a composite material in which concrete's relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength and ductility. In the U.S., the most common methods of doing this are conventional (passive) reinforcing steel, prestressing, and post-tensioning. For strong, ductile, and durable construction the reinforcement needs to have high relative strength, high toleration of tensile strain, good bond to the concrete, thermal compatibility, and durability in the concrete environment. Here is a review of concrete and reinforcement over the past 40 years.
September 1961: The Development of Reinforced Concrete
The art and science of concrete construction has a long history, dating at least to ancient Rome. The development of reinforced concrete, on the other hand, is relatively recent, being scarcely one hundred years old. Numerous men and organizations in Europe and the United States have made major contributions to the understanding and use of reinforced concrete, and our purpose here will be to provide a quick review of some the high spots.
February 1970: Reinforcement -- Why and How -- Part I -- Terminology
The importance of controlling the quality of concrete, from batching right through to curing, is fully appreciated by contractors. But what of reinforcement, the other partner in the team that makes up reinforced concrete? Not so readily apparent or detectable, perhaps, are the omissions or mistakes in reinforcement that could result in a structural failure- potentially far more damaging, possibly disastrous. In order to control the quality and performance of the steel reinforcement system he places, the concrete contractor must know something about the basic theory behind reinforcement, and why it functions as it does in combination with concrete.
May 1970: Reinforcement -- Why and How -- Part III -- Bars and Welded Wire Fabric
Reinforcing steel may be used in concrete either as individually placed and tied bars, or welded wire fabric. The contractor should know something of the properties of each, and where each is most effectively employed, particularly where the two are given as alternates.