The project involved the repair of several continuity slabs in El Castro (León) viaduct, which had cracked and caused potholes in the surface layer. This highway is the main route between Madrid and Galicia, passing through Castille-León, making it important to achieve a reliable, durable repair. It’s a high mountainous area with extreme climate conditions which causes progressive deterioration to the structure. This deterioration is compounded by the grit salt used in the area due to the low temperatures recorded in winter.


COPASA were awarded the contract to conserve and maintain part of the highway stretch and had once again trusted Fosroc repair products to carry out this project. RENDEROC SF, a cementitious repair mortar modified with polymers and fibres for high resistance to compression and abrasion, was recommended to repair the viaduct continuity slabs. This mortar is ideal when high resistance to chlorides and carbon dioxide is required. Firstly, hydrodemolition of the area was carried out to ensure the rest of the structure is not affected by vibrations, and all non-anchored reinforcements were removed and replaced with stainless steel rebars. NITOPRIME ZINCRICH PLUS anti-corrosive primer was then applied to the remaining rebars, followed by bonding mortar and filling with the described cementitious repair mortar.


The customer was very satisfied with the structural strength of the repair and the passivation of the rebars using NITOPRIME ZINCRICH PLUS, which is rich in zinc and combats corrosion through electrochemical means. This results in extending the working life of the viaduct structure.