Determinación de la longitud de transferencia de alambres con distintos grados de corrosión en elementos pretensados de hormigón

Abstract

En elementos pretensados de hormigón, la adherencia entre el acero y el hormigón puede verse deteriorada por diferentes motivos, siendo uno de los más recurrentes el daño inducido por procesos de corrosión. El parámetro fundamental para caracterizar las propiedades adherentes existentes entre el acero pretensado y el hormigón es la longitud de transferencia. Este artículo compara los resultados experimentales obtenidos en ensayos sobre elementos pretensados tipo viga con las predicciones arrojadas por un modelo analítico, basado en la teoría de cilindros de pared gruesa y en la fisuración cohesiva del hormigón, desarrollado para analizar los procesos de degradación de la adherencia motivados por la corrosión en alambres lisos e indentados y su influencia en el comportamiento de elementos pretensados de hormigón.

Transfer length of corroded wires in prestressed concrete members

“…Some novel features of this model are the treatment of the porous layer around the prestressing wires and the volume of cracks occupied by corrosion products to determine the confinement capacity of the concrete cover 37 . An extended explanation of the analytical model can be found in Anaya 32 …”

“…The model variables were calibrated from the results of pull‐out tests on nonstressed wires, and its theoretical results were verified by comparing them with the data extracted from an experimental campaign on prestressed beams. Further details can be found in Anaya 31 and Anaya et al 32 …”

“…By determining the percentage limit of section loss X lim at which the transfer length starts deteriorating and the rate of deterioration V det according to the simplified expressions given by Equation () and Equation (), respectively, the transfer length of corroded wires in prestressed concrete members can be obtained from Equations () and (). However, since there are no extensive experimental studies of the influence of corrosion on the transfer length 29,32 the simplified expression cannot be considered fully validated, and further studies are necessary to demonstrate its predictive ability. Therefore, the proposed expressions can be considered as a good starting point for the development of an expression that allows the evaluation of transfer lengths in corroded prestressed elements.…”