engleski

Time dependent changes of durability properties of concrete from Maslenica Bridge at the Adriatic coast

Among many different environmental actions causing deterioration of concrete, chlorides are presenting one of the most dangerous attacks on reinforced concrete structures. The influence of chlorides on the properties of concrete is multiple, but definitely the most important is that ingress of chlorides eventually causes corrosion of reinforcing steel and degradation of reinforced concrete structures. Permeability properties of concrete cover are crucial for the durability of a whole structure. In order to determine the state of the bridge exposed to very aggressive marine environment, a condition survey on Maslenica Bridge was performed during the year 2006. This bridge is located at the Adriatic coast, exposed to the direct influence of chlorides (with very strong winds and sea effect) for a preceding period of 10 years. In this paper results of concrete mechanical property (compressive strength) and durability properties testing (chloride diffusion and gas permeability) are presented. Concrete testing was performed on-site and in the laboratory on specimens retrieved from the structure. Results of compressive strength, chloride diffusion and gas permeability are compared to the results of initial testing performed on concrete during construction of the bridge (in the year 1996) to evaluate the time dependent changes of these properties under aggressive marine environment.

concrete durability; permeability; chloride profiles; chloride diffusion

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