Impact of Building Maintenance and Rehabilitation on Urban Sustainability: SOS Call for Action–Algarve Case Study

Buildings are designed for a 50-year lifetime. However, they can stand out for more without major repairs, depending on materials quality, climate aggression, use, and maintenance, among other aspects. Considering that Algarve’s building boom occurred between the 60s and 80s, a significant quantity of buildings is achieving their lifetime. Consequently, the demand for rehabilitation is rapidly increasing. Buildings, like other infrastructures, deteriorate over time due to several factors. However, the lack of maintenance stands out, and a structural survey is essential to determine the load capacity and ensure the safety of the society. Corrosion of reinforcement and spalling of the concrete cover may lead to loss of strength and unserviceability. Corrosion is initiated mainly by chloride contamination or exposure to atmospheric CO₂, and the presence of moisture accelerates this degradation processes. In this study, different types of buildings located along the Algarve coastline, suffering from serious structural pathologies resulting mainly from the carbonation of the concrete, are presented. This article describes the constructive pathologies observed and presents the campaign test results, including carbonation tests, the presence of chlorides, corrosion potential, and measurements of covers, among others. These real examples show a rather deteriorated state of the building constructions, which are more than 50 years old in this touristic region. Thus, a priority line on the path towards housing sustainability is urgent. The authors pretend to launch an SOS signal and a call for action, to implement maintenance and rehabilitation plans legally.