Comparison of global and local damage in reinforced concrete columns specimens

Abstract

The accumulation of global and local damage in reinforced high-strength concrete columns is experimentally investigated. Two identical column specimens with annular crosssection and spiral reinforcement were designed and two tests, up to failure, were carried out at the LNEC shaking table facility. Sine type signals, controlled in amplitude, frequency and time duration were used for these experiments. The comparison of global and local damage accumulation illustrates that local damage occurring at the footing accumulates significant of at relatively loading level at microcracking phase. However, local damage has minor effect on the global damage, which significantly accumulates during the stages S3 and S4 during microscopic phase. Index of the global damage reached critical value > dcr 0.8 at the end of macroscopic phase. In the final critical stage the development of both global and local damage exposes similar character.