Avaliação da perda de ancoragem em elementos estruturais submetidos a ataques corrosivos

Abstract

This work presents the results of an experimental program aimed at evaluating anchorage loss in CA-50 reinforcing bars subjected to different levels of induced corrosion. A total of 24 specimens, with diameters of 6.3 mm and 10 mm, were tested at 56 days under geometric reductions of 0%, 10%, 20%, and 30% of the original diameter. Direct pull-out tests allowed the observation of the transition between failure mechanisms, distinguishing cases in which the limiting factor was the steel–concrete bond from those in which the steel integrity governed the collapse. The results showed that while up to 20% diameter loss the failure was still associated with bond degradation, at 30% diameter loss steel rupture became predominant. Thus, the critical threshold for the transition lies between 20% and 30% of diameter loss, providing relevant parameters for diagnostics, prognosis, and intervention strategies in reinforced concrete structures.