Study of the Conditions on Reinforced Concrete Structures with More Than 50 Years of Exploitation

Abstract

Reinforced concrete structures in the mass practice of construction have been used for more than a century. This fact presents challenges for the construction engineer, requiring study of the conditions and assessment of efficiency of the constructions. Especially relevant is the question what is the bearing capacity of the elements and how reliable is the future exploitation of the construction as a whole. In Bulgaria the reinforced concrete has been used since the beginning of 20th century. The first structural concrete was used by the Italian Arnoldo Zocchi in 1903 for the creation of monument of the Emperor Alexander the Second. During the first three-four decades of the 20th century (the second period) the reinforced concrete structures are successfully implemented in housing and community construction. Most of the community and housing buildings of this period already have reinforced concrete bearing skeleton. The third main period of use of steel reinforced concrete constructions is after the World War II. During this period the practice of mass usage of prefabricated steel reinforced concrete constructions is enforced in the Eastern block. Nowadays a big part of the buildings of the Bulgarian industries consists of monolithic and prefabricated reinforced concrete constructions. The results of 70-80 years of exploitation of these buildings and the requirements, enforced by the modern new functions create new tasks for the structures. All these features of the buildings require from the construction engineer knowledge of the study and use of different technological methods of reconstruction.