Smart solution for waterproofing and surface protection

The new bridge over the river Sava west of Gradiška is part of European route E-661, which is currently under construction. Once completed, it will connect the port city of Split on the Dalmatian coast with Banja Luka in the north of Bosnia & Herzegovina, as well as Virovitica in Croatia and Lake Balaton in Hungary. The structure was designed as a continuous, single-cell hollow steel box girder with brackets on both sides. The length of the bridge is 462.25 m and its width is 22.60 m. The costs, estimated at around 23 million euros, are to be borne to the tune of 59 % by Bosnia & Herzegovina and 41 % by Croatia. The contractor chosen for the protection and waterproofing work, BERSIA d.o.o. of Sarajevo, was supposed to start work at the beginning of 2022. However, an originally scheduled and rather complex waterproofing system involving polyurethane-based products in combination with the subsequent covering of the roadways with mastic asphalt had to be shelved due to the associated high costs and the lack of technical experience and equipment in the region. The construction manager of the main contractor, Integral Inženjering PLC, therefore turned to MC to come up with a viable alternative.

MC’s compelling solution

As the entire bridge is made of steel, the MC experts proposed a heat-resistant system consisting of Colusal SP, the corrosion protection primer for steel substrates, epoxy resin-based MC-DUR LF 490 for the deck, and the roller coating MC-DUR TopSpeed for protection of the bridge caps. The decisive advantages of this solution: high impermeability combined with ease of application. The system had already been tested at MC’s HQ in Bottrop – and the client was immediately convinced. The work began in March 2022. The primer Colusal SP, which is also approved as a corrosion inhibitor according to EN 12944-6, was applied in two layers. The road surfaces were then covered with two coats of MC-DUR LF 490. This two-component, translucent red epoxy resin has been developed and tested for waterproofing road surfaces, parking decks, ramps, basins and similar under welded membranes. Finally, bituminous membranes were welded onto the substrate thus prepared, and the surface was covered with rolled asphalt using the standard procedure. The pedestrian walkway and the cycle paths were waterproofed with two coats of MC-DUR TopSpeed, the fast-curing reactive resin based on KineticBoost-Technology® with a full sprinkling of 0.4 to 0.8 mm quartz sand between the layers. The work covered a total area of around 8,000 m² and was successfully completed by the end of May. The clients were more than satisfied: Thanks to MC, they were able to benefit from a safely tested, established system that was more effective than the originally planned solution, with high-cost investments in special equipment and time delays also being successfully averted.