Industrialized countries are facing the continuous aging of their concrete infrastructure exposed to reinforcement corrosion . This inevitable deterioration affects nearly 8 out of 10 structures [ 1 ].

Controlling corrosion has become essential to ensure the durability of reinforced and prestressed concrete structures. Many structures in France will soon reach the end of their service life, requiring significant maintenance and rehabilitation efforts.

Today, the prevailing trend is towards renovation rather than demolition and reconstruction. This shift in approach can be explained by the direct costs of reconstruction (raw materials, labour, etc.), the indirect costs associated with implementing temporary solutions during the works, but also by a desire to conserve the planet’s resources and minimise the carbon footprint.

The widespread ageing of concrete structures

In developed countries, the age profile of reinforced concrete infrastructure reflects a peak in construction during the 1960s. With a theoretical service life of around 50 years for a building and 70 years for a bridge, this lifespan can be significantly reduced in the event of corrosion. Some structures may show the first signs of corrosion after just a few years.

Following the Morandi Bridge disaster, an information mission conducted by the French Senate highlighted the alarming condition of bridges within France’s national road network.

Following this parliamentary mission, the National Bridge Program , led by CEREMA, provided a more accurate assessment of the condition of France’s infrastructure assets. One out of every three surveyed bridges shows significant structural defects that will require repair work in the coming years.

This situation becomes even more alarming for large prestressed concrete structures , where major defects have been identified in more than 7 out of 10 cases. The Saint-Cloud Viaduct is a perfect example. This Parisian structure exhibited the same signs of corrosion as its counterpart in Genoa. The Île-de-France Roads Directorate chose a cathodic protection treatment to stop the corrosion process and extend the structure’s service life by 50 years.