Title:
Durability of Carbon Pretensioned Elements in a Marine Environment
Author(s):
Rajan Sen, Mohsen Shahawy, Satya Sukumar, and Jose Rosas
Publication:
Structural Journal
Volume:
95
Issue:
6
Appears on pages(s):
716-724
Keywords:
bond; carbon fiber reinforced polymer; concrete; durability; fiber reinforced polymer; marine; piles; prestressed
DOI:
10.14359/585
Date:
11/1/1998
Abstract:
This paper presents results from a 3-year exposure study to evaluate the durability of carbon fiber reinforced polymer (CFRP) pretensioned elements which were used as piles in a marine environment. Ten CFRP pretensioned beams, designed to fail in flexure by rupture of the pretensioning rods, were precracked and then exposed to wet/dry cycles in salt water to simulate tide change. Exposed beams were periodically removed and tested for failure to determine their service and ultimate response. Changes in response compared to unexposed control specimens were used to evaluate durability. The results of the study indicate that while concrete’s alkaline environment had no effect on the CFRP rods, the mode of failure was sensitive to the extent of precracking damage sustained prior to exposure. The bond between CFRP and concrete showed evidence of degradation in severely damaged specimens, possibly due to moisture absorption by the epoxy matrix. In less damaged specimens, there was no commensurate bond degradation. Thus, if CFRP is used to replace steel in pretensioned piles, driving stresses should be carefully monitored to prevent any damage.