Assessment of reinforced concrete structures with deficiency concrete-steel stress transfer

Abstract

The behaviour of reinforced concrete as structural material is based on mechanisms of physique-chemistry nature which constitute the bond, such as the chemical adhesion, the friction and the mechanical interaction between the steel and the concrete. It is a general rule to calculate the structures supposing the same deformation for both materials in the contact area, and perfect bond between steel and concrete. However, during the different stages of the constructive process and of the lifetime some circumstances can weaken the interaction concrete/steel. Some project and construction defaults as well as certain pathological phenomenon of environmental origin can give rise to stress transfer mechanisms deterioration between the reinforcement and the concrete. In this article results of an experimental program on reinforced concrete elements in which the tension reinforcement doesn?t present bond in local and partial areas along its longitude are presented. This study is part of the Research Project PB98-0515 ?Assessment of reinforced concrete structures with a deficiency concrete steel stress transfer? financed by the Ministry of Education and Culture (2000 ? 2002).