Title: Behavior Of FRP Wrapped Cylinders Under Various Environmental Conditions

Author(s): Muhammad Faizan Qureshi, Shamim A. Sheikh, Zahra Kharal

Publication: Symposium Paper

Volume: 358

Issue:

Appears on pages(s): 41-61

Keywords: concrete, confinement, compressive tests, cylinders, durability, elevated temperature, freeze-thaw cycles, FRP wraps, reduction factor

DOI: 10.14359/51740230

Date: 9/1/2023

Abstract:
Twenty-eight unwrapped and wrapped concrete cylinders were tested in this investigation to assess two environmental conditions, sustained elevated temperatures (ST) and freeze-thaw (FT) cycles. The concrete cylinders were wrapped with a single layer of GFRP and CFRP wrap. GFRP wraps improved concrete strength by up to 30% and ductility in excess of 600% for ambient condition specimens, while the enhancements in strength and ductility under the same conditions by CFRP wraps were about 70% and 700%, respectively. The strength enhancements were reduced severely for specimens tested under ST protocol beyond the glass transition temperature (Tg) with a minor reduction in ductility enhancement. On the other hand, freeze-thaw conditioning showed minimal effect on strength and ductility enhancements provided by the FRP wraps. The current and past findings were then used to suggest environmental reduction factors for the design of FRP wraps. A comparison of these factors with ACI 440.2R-17 showed that environmental factors suggested by the ACI code were not applicable at temperatures beyond Tg.