Built in the Sado River estuary during the 1970s, the Lisnave dry docks are a key infrastructure for shipbuilding and ship repair. Over the years, the docks have undergone extensive maintenance, conservation, and repair efforts. In the 1990s, they were the subject of a major structural rehabilitation project, during which 38,000 m² of concrete on the dock walls were repaired. Around twenty years later, a new phase of rehabilitation was carried out.

Technique used

The intervention included the repair of approximately 18,000 m² of concrete on the bottom slabs, two kilometers of technical galleries, and a repeat repair of 5,000 m² of wall surfaces.

The concrete repair technique used involved the removal of deteriorated concrete by hydrodemolition, followed by the application of dry-process shotcrete using double-chamber machines. This technique has proven highly durable over the twenty years since the previous wall repair. In such an aggressive environment, the recurrence rate of repairs was just 10% after two decades.