Damage mechanics applied for steel reinforcements in concrete structures under corrosion

Abstract

Structures of reinforced concrete, as any another structure that uses metallic components, are subjected to corrosion, being this, one of the main factors for the degradation of these structures. Thus, a study of this phenomenon is very important to describe the mechanical behavior of them. This study has as main objective to analyze the degradation of the mechanical properties of steel bars used in the civil construction, considering the effect of corrosion in these properties, and to develop a simplified model for the evolution of the damage, through the Continuum Damage Mechanics theory. Steel bars specimens were confectioned and submitted to an accelerated corrosion test (Salt Spray) for different intervals of time. After the corrosion test, the specimens were submitted to a tensile strength test with loading and unloading, getting the elasticity modulus for each unloading. Then, the concept of measure of damage through the variation of the Elasticity Modulus, introduced by Lemaitre, was applied. The damage in function of the deformation for each specimen was obtained. Finally, with the analysis of the damage in the different specimen, the variable Damage in function of the mechanical loading and the corrosion was written.