The Porto Santo pier is a reinforced concrete structure built in the 1920s. It consists of a solid slab supported by two main longitudinal beams. These beams are continuous, with a slight increase in cross-section near the supports, and span 10 meters. Transversely, there are crossbeams (carlingas), both mid-span and at the supports, which are composed of pairs of columns founded on footings. 

Intervention goal

Due to the structure’s age—80 years—and the aggressive environmental conditions, particularly the harmful action of chloride ions, widespread severe corrosion of the reinforcement steel had occurred, leading to delamination of the surrounding concrete. 

Steps and techniques used

The established methodology for rehabilitating the structure, covering a total intervention area of 2,000 m2, consisted of a complete reconstruction of the slab in order to maximize the reuse of the beams and columns. These structural elements were rehabilitated through full encapsulation with structural reinforced concrete applied by dry-process shotcrete using dual-chamber machines. The structures were then protected by the application of a waterproof cementitious coating.