Corrosion monitoring of post-tensioned strands at the Piedra del Aguila spillway

The Piedra del Aguila project in Argentina is a concrete gravity dam constructed in the 1980s, on the Limay river. The dam includes a spillway channel controlled by four gates. The spillway structure includes several post-tensioned systems installed in the concrete piers. These systems do not meet the cable protection standards of modern methods, which provide two barriers against corrosion and can be monitored. In 2004, several leaks were detected that could have reached the steel tendons. Because of this, an innovative programme was developed to ascertain the integrity and remaining life of the steel strands. This paper presents a summary of the activities performed and the instrumentation installed at Piedra del Aguila to assist with the long-term monitoring of the dam.