Title: Durability of Carbon Fiber Reinforced Polymer (CFRP) Pretensioned Elements under Tidal/Thermal Cycles

Author(s): Rajan Sen, Mohsen Shahawy, Satya Sukumar, and Jose Rosas

Publication: Structural Journal

Volume: 96

Issue: 3

Appears on pages(s): 450-457

Keywords: bonding; carbon; durability; moisture; piles; prestressed concrete; temperature

DOI: 10.14359/681

Date: 5/1/1999

Abstract:
This paper presents results from an experimental study to assess the likely effect of diurnal/seasonal temperature change on the durability of carbon fiber reinforced polymer (CFRP) pretensioned piles driven in tidal waters. Twelve precracked CFRP pretensioned beams designed to fail by rupture of the prestressing rods were kept outdoors in two salt water tanks and simultaneously subjected to wet/dry cycles (simulating tides) and hot/cold cycles (simulating temperature variation). Durability was assessed from flexure tests conducted periodically over the nearly 3-year exposure period. The results of the tests indicated that durability was largely unaffected, although both bond degradation and reductions in ultimate capacity were observed in some of the exposed specimens. Degradation appeared to be linked to the extent of precracking damage sustained prior to exposure. This suggests that when CFRP pretensioned piles are used, driving stresses should be carefully monitored to minimize damage.