CONDITION EVALUATION FOR THE QUEEN ISABELLA CATHODIC PROTECTION PROJECT

摘要

Four different cathodic protection systems will be evaluated in tie beams and footings of the Queen Isabella Causeway which links South Padre Island to the mainland of Texas. This paper will describe the results of the pre-installation condition survey. The purpose of the pre-installation condition survey was to assess the condition of the structure and the feasibility of cathodic protection as a rehabilitation option. The condition evaluation included the following: visual inspection, delamination survey, cover survey, half-cell potential measurements and chloride content determination, At the footings, condition indicators evidencing more corrosion activity were found on the south footing than in other footings. This is due to the prevailing north wind and wave action in the area. At the tie beams, the construction joint is largely responsible for the deterioration as evidenced by the existence of cracks and high chloride contents. Electrical continuity, concrete cover survey and overall condition of the structure deem this structure as a good candidate for cathodic protection.