Theoretical Performances of RC Elements Built at Turn of the Century

In the 19th century, the invention of reinforced concrete (RC) technology paved the way for innovation in building methods, though its actual mechanical behavior was not fully understood for some time afterwards. The early period of the inventors and builders, such as Jean Bordenave, Paul Cottancin, A. Bonna, François Hennebique, Edmond Coignet, and N. de Tedesco, was followed by a time of intensive activity for the theorists, who developed several accurate analysis methods. A considerable contribution to this success came from the builders themselves, who adopted methods capable of achieving an effective distribution of the reinforcement, and from the technical literature, which facilitated the growth of this new technique. Initially, the theories were somewhat confused because different, sometimes contrasting approaches were used by different authors. By way of example, suffice it to mention the hypotheses developed by Mattias Koenen, P. Neumann, Edmond Coignet, N. de Tedesco, Max Ritter von Thullie, Josef Melan, J. B. Johnson, Léon Stellet, L. Lefort, F. Chaudy, Josef Anton Spitzer, Wilhelm Ritter, and Armand Considère. However, RC became a highly successful material for the 20th century, capable of satisfying the most challenging demands of designers and customers. In this paper special attention is paid to the contribution of the theories suggested at the time, in order to verify their validity in relation to our present understanding.