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CONTINUATION OF REPAIR AND PROTECTION WORKS ON THE KRK BRIDGE

Design and construction of the Krk Bridge was very delicate and bold engineering introducing many innovations and breaking records. Its maintenance during last 30 years was equally challenging. The bridge is set in aggressive maritime environment, with its main members like foundation elements and lower parts of the arches being most exposed. Nearly all columns and lower parts of the arches have been protected over the past decades. Cathodic protection was envisaged for the submerged elements that support the larger arch of the Krk Bridge, and that work is currently being executed. Concrete surfaces of the bridge that are 25 m above the sea will be protected by pure polymer coat. During 2010 an investigation into the efficiency of coatings available on the market was carried out. This included laboratory and on- site testing, as manufacturers were invited to apply coating on “trial” surfaces at three locations on the bridge. The works on the Krk Bridge initiated a further research into durability design of reinforced concrete structures in aggressive maritime environment. Experience gained on several large reinforced concrete bridges in Croatia in maritime environment has revealed that to achieve adequate durability and specified service life, usual measures prescribed in standards such as concrete mixture properties and concrete cover thickness should be combined with surface protection systems. Research is focused on the efficiency of reinforced concrete surface protection systems in preventing the ingress of aggressive substances into concrete, and development of models to predict service life of reinforced concrete members where resistance is represented by the integration of a protective system and concrete cover.

arch bridge; durability; corrosion; maintenance; protection

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