Structural and economical performance of reinforced concrete frames with Dual‐Phase and TempCore® steel rebars in uncorroded and corroded conditions

Abstract

In the last decades, the need to develop new enhanced typologies of steel reinforcement bars with improved ductility and durability performance in presence of aggressive environmental conditions progressively increased due to the negative consequences that corrosion showed on the structural capacity of reinforced concrete (RC) buildings. Within the recently concluded NEWREBAR research project, a new reinforcing steel grade with Dual‐Phase (DP) microstructure and selected low‐carbon content chemical composition (kept in the range of the actual European production) was developed, produced, and tested even in presence of accelerated induced corrosion. To understand the impact of the adoption of DP rebars in RC structures, case study buildings were designed, modeled, and analyzed using the new grade and compared to traditional buildings using TempCore® rebars. In the present work, the results of a techno‐economic analysis performed on both DP and TempCore® RC buildings through the evaluation of the expected annual loss (EAL) index is presented for a residential five‐storeys case‐study building, assessing the benefit introduced by adopting the proposed new reinforcing grade even in presence of corrosion.

Long‐term shear strength of RC beams based on a mechanical model that considers reinforcing steel corrosion

“…The reduction in the overall beam height is considered only for the very heavily corroded beams from reference 6 (being the web reinforcement section loss ratio, see Notations for a detailed definition). Despite the reasonably satisfactory results obtained by comparing the shear strength predictions by the CCCM extension for corroded beams with the empirical results for the slender beams included in the database, future developments (outside the scope of this article) should include consideration of bond deterioration, 30,31 reduction of concrete compressive strength at cracked concrete and change in the mechanical properties of the deteriorated bars 32,33 …”

“…Correlation of the experimental results and prediction versus the cross-sectional loss ratio of stirrups. CCCM, Compression Chord Capacity Model; CoV, coefficient of variation reduction of concrete compressive strength at cracked concrete and change in the mechanical properties of the deteriorated bars 32,33. …”

Predicción a largo plazo de la resistencia a cortante de vigas de hormigón armado basada en un modelo mecánico considerando la corrosión de la armadura

“…La reducción del canto se considera únicamente para las vigas severamente corroídas, ηw,sn>75%, de la referencia [6] (siendo ηw,sn el ratio de pérdida de sección de la armadura a cortante, ver la Notación para una definición más detallada). A pesar de los resultados razonablemente satisfactorios obtenidos al comparar las predicciones de la resistencia a cortante usando la extensión del CCCM para vigas que han sufrido ataques por corrosión con los resultados empíricos para las vigas esbeltas incluidas en la base de datos, desarrollos futuros (fuera del alcance de este artículo) deberían incluir la consideración del deterioro de la adherencia [30,31], la reducción de la resistencia a la compresión del hormigón fisurado y el cambio en las propiedades mecánicas de la barras corroídas [32,33]. Figura 4.…”

Study on Flexural Performance of Architectural Concrete Beams Under Steel Bar Corrosion Conditions

“…However, in practical applications, particularly in coastal buildings [3], RC beams are susceptible to steel corrosion due to external environmental influences [4]. In the presence of reinforcement corrosion, the load-bearing capacity of RC beams decreases [5], leading to potential issues such as cracking and spalling. These issues significantly affect the service life of RC beams, resulting in economic losses and even more serious consequences like bridge failure or collapse.…”