Krk Bridge

The high salinity of the water (3.5%) combined with the wind accelerated the penetration of chlorides into the Krk bridge elements, columns, and arches, provoking the corrosion in the reinforcing bars as well as microcracking, spalling, and deterioration of the concrete cover. Therefore, it was decided to perform repair works on both, columns and arches. The surface layer of concrete is first removed, and then new layers are added either using classical concrete pouring or shotcrete.

Aim of monitoring:

To estimate the performance of repaired columns, control reconstruction works, and increase the knowledge concerning the interaction between the new and the existing concrete, it was decided to equip two columns (S20 and S26) with a total of eight two meters long sensors and four thermocouples (four sensors and two thermocouples per column) from Smartec. The sensors are installed onto the surface of the old concrete, in appropriate grooves, and then protected with stainless steel profiles. In the future, the same sensors will be surrounded by the new concrete and in this way, the complete history of repair will be registered. 

Main results:

In the first stage (August 2002 – May 2003) the behaviour of existing columns was monitored during the traffic. In May 2003, the superstructure of the bridge is lifted using the jacks, and the column is unloaded. This operation is successfully monitored using the SOFO system. In the next period the old concrete cover will be destroyed by hydro blasting and the existing sensor will be embedded in the new concrete.

Please contact us for more information regarding our sensor technology for bridge monitoring applications and read through our other case studies from Smartec and our sister company Roctest.