Experimental investigation on shear behaviour of corroded and repaired prestressed concrete beams

Abstract

In this paper, an investigation on the shear capacity of naturally corroded prestressed concrete (PC) beams without transversal reinforcement is presented. At first, to estimate the corrosion level, a visual inspection was carried out to detect concrete spalling and cracking, together with chloride concentration, as well as potential, resistivity, and corrosion rate measurements. Moreover, in the damaged areas, measurements of cross-section and weight loss for reinforcement were carried out. Then, the beam was repaired, and full-scale tests were conducted. To evaluate the effectiveness of the repairing system for shear capacity, full-scale tests were conducted by applying a concentrated load close to the ends of the beam - where the strands were subjected to corrosion - and close to the central part of the beam - where strands were uncorroded. The experimental results highlight that, since the repairing system is not able to restore prestress, the shear capacity is strongly reduced also after reparation.