Evaluación de la durabilidad del hormigón armado en tres estructuras en Manta posterior al sismo del 2016 con ensayos no destructivos

Abstract

This project assesses the durability of reinforced concrete in three in-service residential buildings in Manta, Ecuador, considering post-earthquake conditions (16 April 2016) and different levels of coastal exposure. The objective is to characterize the current condition of concrete and indirectly appraise reinforcement corrosion risk to prioritize preventive maintenance; it is hypothesized that higher marine exposure is associated with less favorable durability indicators. The work is justified because it uses non-invasive techniques applicable to occupied buildings. A visual survey was used to define representative points on beams and columns, and non-destructive tests were applied: rebound hammer testing to estimate compressive strength (Rc), ultrasonic pulse velocity (UPV) to evaluate internal continuity, and surface electrical resistivity (Wenner) as an indicator related to ionic transport; corrosion current density (Ic) was also computed and classified. Data processing included descriptive comparison, analysis of variance, and multiple linear regression with Ic as the dependent variable and Rs–UPV as predictors. Results showed that the most exposed structure had UPV < 3.3 km/s and Rs < 10 kΩ·cm, together with Ic > 1 μA/cm², indicating conditions favorable to intense atmospheric corrosion, with higher relative severity in columns. The other structures exhibited higher Rc and UPV with low variability, although Ic remained > 1 μA/cm² and the most affected element type differed between cases. Overall, the combined END approach provides a consistent diagnosis of durability and corrosion risk, and decreasing Rs and UPV significantly predicts increasing Ic (p < 0.05). Keywords: Durability; Reinforced concrete; Surface resistivity; Ultrasonic pulse velocity; Corrosion.