The pile bents using the prestressed piles with minor corrosion had a ductility

factor of approximately three. That represented a reduction of approximately 23% of its

original ductility factor. In addition a significant strength reduction of approximately 15%

was associated with the same pile bent. Knowing that the process of steel corrosion

begins immediately after installation it is logical to assume that during the first 10 years

of the life of the piles at least minor corrosion damage will take place. With in

approximately 20 years moderate corrosion damage is also possible. In such a case the

steel reinforced prestressed piles will be in service having less ductility than the pre-cast

prestressed CFRP reinforced piles. The corrosion damage will also reduce the capacity of

the steel reinforced piles as the results of the St. George Island Causeway piles suggest.

For moderate corrosion damage a strength reduction of up to 35% is possible which is

very significant. The pre-cast prestressed CFRP pile bents initially have a ductility

disadvantage compared to the steel prestressed pile bents but with in the first 20 years

they actually became more advantageous than the steel prestressed pile bents. In time

their advantage becomes greater because further reduction of both the ductility and

strength is a strong possibility based on the results available from St. George piles.

 It is reasonable to assume that for at least the second half of their lifespan the steel

prestressed pile bents are less safe than pre-cast prestressed CFRP pile bents both in

terms of strength and ductility. That is true if the life span of the pile bents is

approximately 35 to 40 years. If the expected life is longer then the steel prestressed pile

bents will be less safe than the pre-cast prestressed CFRP pile bents for the larger portion

of their lives.