A CONDITION ASSESSMENT OF PILE JACKETS UPON FLORIDA COASTAL BRIDGE SUBSTRUCTURES

Corrosion and mechanically damaged bridge pilings in Florida coastal waters have, since the 1940's, been repaired and rehabilitated by jacketing; that is, by 1) removing loose concrete, 2) placing a formwork about the damaged zone (usually from mean low water to a height of several meters), and 3) filling the annulus with mortar or concrete. However, removal of jackets from pilings of two bridges that were being rehabilitated revealed that reinforcement corrosion was often severe and structural integrity reduced. Consequently, a condition assessment of jacketed pilings on 19 representative bridges was performed. This involved a visual condition assessment followed by removal of a portion of the jacket and characterization of the underlying condition. The pre- and post-inspection conditions were quantified using a Numerical Condition Rating (NCR) with the difference between the two values (deltaNCR) being taken as a measure of the extent to which piling damage was obscured by the jacket. Influences of jacket age, jacket type, pile reinforcement type (prestressed versus conventional), and piling pre-jacketed condition were evaluated. A mechanism for the deterioration is proposed, and a recommendation was made that jacketing be discontinued as a stand-alone piling repair/rehabilitation strategy. For the covering abstract see ITRD E116313.