'We can't fix corrosion, but we can stop it'

Effective concrete maintenance

Wherever concrete is used, it makes a strong, robust impression. Rightly so. But despite this natural strength, concrete is and always will be subject to external influences. Once oxygen and moisture reach the reinforcement, corrosion is inevitable and the concrete loses its strength. This happens in young and old buildings, in balconies, galleries and apartment buildings and in bridges, overpasses, tunnels, parking garages and more.

Meanwhile, there are several methods for minimizing corrosion damage. Leggedoor Onderhoudsgroep in Stadskanaal, Groningen, specializes in concrete maintenance and offers a solution for every infestation. "We can't fix corrosion, but we can stop it," said Dennis Leggedoor, director/owner of Leggedoor Onderhoudsgroep.

Cathodic Protection

Already since 1993 - and yet still in limited use in the Netherlands - there is Cathodic Protection. Here the reinforcement iron is protected by a minimal current of electro-ions conducted through the concrete. This stops the corrosion of the reinforcement and moves it to the installed anodes. "The method is very effective and leaves hardly any traces," explains Leggedoor. "In the countries around us this method is often used and in the Netherlands it is still limited. This probably has to do with cold feet. In the Netherlands, we only opt for a new method when it has proven its worth in all respects."

Coating

One way to preserve concrete in the long term is coating. Unlike Cathodic Protection, this method is widely used. "Coating concrete is a treatment that many parties can expertly perform. The secret is in the preparation. If the concrete is properly cleaned beforehand and adhesion is guaranteed, coating - if properly maintained - is a very effective long-term approach."

Conventional repair

Conventional concrete repair requires more specific knowledge. For this, Leggedoor Maintenance Group has in-house concrete maintenance experts at all levels and trained in a variety of specialties. "A 100% safe method," guarantees Leggedoor. "Just think of sealing by impregnation or injection, repair and reinforcement. Depending on the customer's needs and budget, the traces of the repair can be completely eliminated."

Reinforcing concrete structures

A technique that is becoming increasingly common within the Leggedoor Maintenance Group is the reinforcement of concrete structures. This does not directly involve concrete repair, but reinforcement of the concrete structure so that it can withstand increasing traffic flow. This can be done by strengthening the infrastructure, but also by installing external reinforcement. "In the latter case, we speak of a 'carbon lamella.' There are no products in this lamella that can rust. So they offer reinforcement in the long term and without risk."

"Concrete retains its strong appearance even when its strength is undermined from within," Leggedoor concludes. "Are there reasons to doubt the strength of concrete elements? Have it investigated! In Genoa, Italy, the Morandi Bridge collapsed, 45 meters above the Polcevera River. And in the Delfzijl area, we recently understamped an apartment building. We have to prevent situations like this."