History

Many people say that a Frenchman, J. Monier, who took out apatent in 1867 for the construction of plant tubs, tanks, etc., made of concrete reinforced with a mesh of rods or wires, should be credited with the invention. Certainly Monier did a great deal to develop the use of reinforced concrete and his name came to be so closely linked with reinforced concrete that reinforced concrete was known as the Monier System.

Wilkinson, however, certainly appears to have been the first. His patent covered for concrete floor slabs reinforced with a network of flat iron rods placed on edge. One of his main claims was the good fire resistance of the floor. He appears to have understood the principles of reinforced concrete, for he stated that the reinforcement was to be placed in the concrete to take the tension.

A number of buildings were erected, using Wilkinson’s system. He also described method for the construction of pipes, reservoirs, and walls of concrete reinforced with metal sheets, bars and chains.

Freyssinet is known for his work in prestressed concrete for which he had his first ideas before First World War. With the improved materials and the new knowledge available, Freyssinet realized the advantage to be obtained from prestressing, and he used his system in prestressed works.
From now on structures became bigger, better and more exciting, and concrete steadily strengthened its position as a building material. Reinforced concrete was recognized as the best material for all types of structures.

The post-war era has given the biggest boost to concrete, both reinforced and prestressed. After the war steel was short in Europe and many architects had to use either reinforced or prestressed concrete in their structures in order to economize in steel.

Architects were perhaps a little surprised to discover that in many cases reinforced concrete structures, apart from using the minimum of steel, where also cheaper than other forms of construction, and could be erected as quickly. They also discovered that they had more freedom for planning than they had ever before, and a larger number of different solutions to each structural problem were available.

Beams could be eliminated, floor spans could be increased, and shells were available for roofing large areas. Another big factor, which encouraged the use of concrete, was the introduction of fire regulations, which recognized the superiority of concrete over other structural materials in its fire resistance properties.