Coastal Construction: The Challenges of Cement in Dakhla

Construction in coastal areas presents specific challenges related to the marine environment. Sea spray, loaded with sodium and magnesium chlorides, penetrates the porosity of the concrete and attacks the metal reinforcement, causing corrosion. This phenomenon, known as accelerated carbonation, is the primary cause of degradation of seaside structures.

In Dakhla, the combination of marine humidity, sandy winds and significant thermal amplitudes creates a particularly aggressive environment for concrete structures. Structures exposed to the northwest, the direction of the prevailing spray-laden winds, are the most vulnerable. It is therefore crucial to choose an appropriate cement and to respect the rules of the art for marine reinforced concrete.

Dakhla Aménagement's CPJ 55 is particularly recommended for structures in coastal areas. Its superior strength produces a denser and less permeable concrete matrix, slowing the penetration of chlorides. Combined with a reinforcement cover of at least 5 cm and a water/cement ratio of less than 0.45, it guarantees optimal durability of maritime structures.

Complementary measures include the use of water-repellent admixtures, the protection of exposed faces with waterproofing coatings, and prolonged curing of fresh concrete. Regular maintenance, including visual inspection of cracks and refurbishment of protective coatings, contributes to significantly extending the lifespan of coastal structures.