Cortec’s Migrating Corrosion Inhibitor technology has been used in restoration works for historic monuments in Croatia, including the Church of St Donatus in Zadar and the medieval city walls of Ilok.

The Church of St Donatus, one of the most significant pre-Romanesque churches in Europe, is listed in the Register of Cultural Goods of the Republic of Croatia and is under UNESCO protection. The monument required urgent rehabilitation after 3D scanning analysis identified critical issues in the church walls, main structure and roof.

The reinforced concrete support structure beneath the roof, installed between 1927 and 1930 to improve stability, had been affected by moisture penetration and corrosive sea spray. Cortec’s MCI 2020 surface-applied corrosion inhibitor was specified as a coating to protect the structure against further corrosion.

MCI 2020 is designed to migrate through dense concrete structures and protect embedded steel reinforcement. According to the company, the environmentally safe inhibitor helps stop further corrosion of reinforcing metals and extends the service life of the structure.

Cortec technology was also used in the renovation of the medieval city walls of Ilok. The town’s fortress walls and royal castle are protected heritage assets. Over time, atmospheric exposure had caused the mortar between bricks to deteriorate, affecting the masonry.

Restoration work on Tower Three included strengthening foundations, rebuilding collapsed sections and injecting cracks to restore structural integrity. MCI-2005 was added to the new concrete foundation supporting the old foundation, while MCI-2018 was applied to the brick walls.

As a Migrating Corrosion Inhibitor admixture, MCI-2005 protects embedded metal reinforcement in concrete, particularly where the new foundation comes into contact with soil. The project used black steel reinforcement with MCI-2005 instead of stainless steel reinforcement.

MCI-2018 acts as a water repellent, helping protect brick and mortar from outdoor weathering without changing the appearance of the historic structure. MCI-2005 is also a USDA Certified Biobased Product.

Cortec said the integration of MCI technology in these restoration projects supports the sustainable preservation of Europe’s cultural heritage assets while improving the durability and service life of repaired structures.