Projects / 8/14/2024

Renovating the interior coatings in the Golovec tunnel

The upgrading works involved repairing cracks and applying a coating with a high reflectance index

The Golovec tunnel along A1 motorway near Ljubljana underwent significant refurbishment to repair interior coatings and enhance safety. Mapei products were used to repair cracks, level surfaces, and apply a high-reflectance coating, improving visibility and ensuring long-term protection of the tunnel's concrete surfaces.

The Golovec Tunnel is almost 600 m long and is located on the ring road to the east of Ljubljana along the stretch of the A1 motorway running between Bizovik and the Malence interchange. Completed in 1999, very little maintenance was carried out for the following twenty years until, in 2020, complex renovation work was carried out on both tubes of the tunnel to remediate damage caused by wear in general and the penetration of rainwater also due to the specific characteristics of the soil.

Mapei d.o.o., the Group’s Slovenian subsidiary, played a part in the project by supplying the company’s solutions and products to renovate the coating on 9,500 m² of internal concrete surfaces. The new coating, which arrives at a height of 4 m, extends for the entire length of the two tubes and protects the concrete surfaces from the penetration of aggressive substances and the effects of the weather. The coating also has a high reflectance index, thereby improving visibility and safety.

Preparation of the substrates

To guarantee sufficient adhesion for the new protective layer, the old finish and mortar applied in the past had to be completely removed to make sure the concrete surfaces were flat and even.

The next step was to blast the surfaces with water at high-pressure using robotic cleaning machines. In the areas where it was not possible to clean the surfaces with this method, they were abraded manually with diamond discs.

All the badly damaged areas of concrete were reintegrated with MAPEGROUT T60 fibre-reinforced, shrinkage-compensated, sulphate-resistant thixotropic mortar, ideal for concrete repairs. Because these areas were rather small, the mortar was applied by hand with trowels.

The cracks in the concrete surfaces were sealed with EPOJET LV two-component, low viscosity epoxy resin, which was injected with IDROSTOP MULTI ST12 metal packers until the cracks were completely filled.

The Golovec Tunnel near Ljubljana was recently renovated and the internal surfaces were provided with a new coating.

Levelling and finishing the internal surfaces

Before applying the final finish, all the surfaces were skimmed with TRIBLOCK FINISH three-component, thixotropic epoxy-cementitious mortar to create an even, compact, waterproof layer resistant to abrasion. After applying two layers of this product, the surfaces in the tunnel were finished off with MAPECOAT W HRI two-component epoxy paint in water dispersion. This type of paint is easy to apply either by spray, brush or roller. In this case, it was applied in two coats using a roller. Thanks to its chemical composition, it guarantees long-lasting protection for concrete surfaces against external agents, a high level of cleanability and a high reflectance index, characteristics that help improve visibility and safety when driving through the tunnel.

The renovation work also included an upgrade of the ventilation, lighting and safety systems. The Golovec Tunnel is the first one on the Slovenian motorway network to have modern LED lighting, which guarantees efficient energy savings. It also has an automatic traffic control system which allows any incident to be monitored very accurately. All these features, together with the high quality materials used to renovate the coating inside the tunnel, will work together to guarantee high safety standards for years to come.

After preparing the substrates, sealing the existing cracks and repairing portions of deteriorated concrete, the internal surfaces were skimmed with TRIBLOCK FINISH mortar and protected with MAPECOAT W HRI epoxy paint.