Damage assessment in RC columns using the energy dissipation of ultrasonic waves

Abstract

Reinforced concrete (RC) columns, widely used in various types of structures, are prone to significant damage from cyclic loads, such as seismic events or repeated stresses, particularly in older buildings. Accurate damage assessment is crucial for ensuring safety and reliability or determining the need for reinforcement. Traditional evaluation methods often involve time-consuming invasive techniques, whereas non-destructive testing (NDT) methods provide innovative approaches to monitor and assess structural health swiftly and without causing additional damage. This paper investigated the damage assessment in reinforced concrete columns subjected to alternating cyclic loading by calculating the damage index based on ultrasonic energy dissipation. To achieve this, non-destructive tests were conducted alongside mechanical tests. Ultrasonic signals of waves passing through the material, as well as displacements at the top of the columns, were recorded for each loading cycle. The extent of damage, represented by the damage index (DI) value, was estimated using the proposed model, which is based on variations in ultrasonic signal energy. The comparison between the results obtained with the proposed model and those from other authors demonstrates the effectiveness and validity of the proposed model based on ultrasonic signal energy for damage index evaluation. Additionally, this approach facilitates the assessment of structural conditions after an earthquake and enhances structural health monitoring (SHM).