Old Bridge Given a Face Lift

After 70 years of use, a pedestrian bridge over the Czech river Lužnice had to be completed refurbished. Product systems from MC were used to ensure that the bridge is properly protected for decades to come.
Located near the town of Harrachov is a reinforced concrete bridge that takes foot traffic over the river Lužnice. Since its construction in 1940/41, this bridge in its idyllic, green setting – particularly popular with hikers – underwent only minimal maintenance, i.e. a new coat of paint every now and then. However, the tide of time and heavy flooding in 2002 had weakened the fabric of the bridge to such an extent that careful, extensive repair and restoration became increasingly urgent. In 2013, the city of Tabor made monies available to enable the bridge to be returned to its former glory.
Reliable systems

In April 2013, the old railings and the paving were removed and the substructure cleaned up and prepared using high-pressure water jetting. CFRP panels were then adhesive-bonded in place to provide reinforcement and stabilisation. The contractor Libor Ryba, a long-standing MC customer, used the duromer MC-DUR 1280 for the job. This two-component epoxy-resin-based adhesive develops high mechanical strength very quickly, even at low temperatures. In order to select suitable systems for the concrete repairs, trials were also carried out with MC’s Nafufill product system, the results of which appropriately impressed both the client and the planning engineers.
As a result, Nafufill KM 110 was used to level the non-pedestrian (i.e. unloaded) surfaces. The poly-mer-modified fine mortar offers high water retention capacity and application flexibility, making it ideal for the job. It is also resistant to freeze/thaw and thermal cycling. The bridge copings and substructure were completely reprofiled with Nafufill KM 250. Further structurally relevant components were refurbished using MC’s fibre-reinforced PCC concrete repair and replacement. The system is resistant to de-icing salt and chloride-proof and exhibits a high degree of resistance to carbonation. It can thus be relied upon to protect the reinforcing steel. It is also fire-resistant and structurally effective.

Excellent protection for the coming years

Finally, Nafufill BS was also applied as a surface protection coat. The ready-to-use, pigmented system is non-flammable, weather-resistant, UV-stable, and resistant to acids, alkalis and salt solutions. It is highly resistant to carbonation and open to water vapour diffusion. It can also be used in the de-icing salt spray zone. For the first time in the Czech Republic, the unique surface protection system MC-DUR 2496 CTP was used for the bridge deck, offering not only high mechanical strength but also excellent application properties. These allow it to be brushed, rolled or sprayed onto the recipient surface. MC-DUR 2496 CTP also exhibits a relatively long pot life yet offers all the advantages of accelerated curing once applied, and is particularly effective in the presence of moisture and low temperatures. The product is quickly overworkable and excels in terms of its high scratch, scuff and abrasion resistance.
Thanks to advanced technologies combined with excellent coordination and collaboration, hikers using the bridge with its brand-new steel railings will be unaware of its age. And, for the next 70 years or so, they can be sure that it will take them safely over the Lužnice.