Title:
Durability of Aramid Pretensioned Elements in a Marine Environment
Author(s):
Rajan Sen, Mohsen Shahawy, Jose Rosas, and Satya Sukumar
Publication:
Structural Journal
Volume:
95
Issue:
5
Appears on pages(s):
578-587
Keywords:
aramid fiber reinforced plastic (AFRP); bond; durability; piles;
fiber reinforced plastic (FRP); prestressed;
DOI:
10.14359/572
Date:
9/1/1998
Abstract:
This paper presents results from a 3-year exposure study to evaluate the durability of aramid fiber reinforced plastic (AFRP) pretensioned elements used as piles driven in a marine environment. The aramid/epoxy composite ARAPREE was used in the investigation. Ten AFRP pretensioned beams designed to fail by rupture of the pretensioning rods were pre-cracked and then exposed to wet/dry cycles in saltwater to simulate tide change. Exposed beams were periodically removed and tested to failure to determine their service and ultimate response. Changes in response relative to that of unexposed control specimens were used to evaluate durability. The results showed that exposure had a relatively minor effect on the ultimate capacity of the AFRP pretensioned beams. However, there was evidence of bond deterioration in the failure mode of specimens exposed for two or more years. More importantly, characteristic bond splitting cracks developed in one beam that had been exposed for 3 years. This suggests that while AFRP may have adequate chemical resistance to concrete’s alkalinity, its bond with concrete is vulnerable under wet/dry cycles. Thus, AFRP is not the ideal candidate for replacing steel in pretensioned piles driven in tidal waters.