Title:
Axial Load-Bearing Concrete Confined with Carbon Fiber- Reinforced Polymer Sheets in Acidic Environment
Author(s):
Yail J. Kim and Yongcheng Ji
Publication:
Structural Journal
Volume:
114
Issue:
3
Appears on pages(s):
775-786
Keywords:
carbon fiber-reinforced polymer (CFRP); compressive behavior; durability; sulfuric acid
DOI:
10.14359/51689464
Date:
5/1/2017
Abstract:
This paper presents the axial behavior of plain and carbon fiber reinforced polymer (CFRP)-confined concrete in an acidic environment. Despite extensive investigations of its durability, there still is a research gap in understanding the performance of confined concrete under this detrimental condition. Various exposure conditions are tested to deteriorate the concrete with a 5% concentration sulfuric acid solution. Ancillary tests are conducted to characterize the effect of acid exposure on the materials’ strength and physical properties, including thermogravimetric analysis. The efficacy of CFRP confinement is examined using 72 concrete cylinders. The performance of the constituent materials is degraded by acid exposure. The presence of CFRP wrapping disturbs the permeation of the acid into the core concrete, and impedes chemical reactions associated with the concrete-acid interaction. With an increase in acid exposure time, the effectiveness of the CFRP wrapping is reduced. The extent of initial core damage (prior to CFRP wrapping) is an important factor influencing the capacity, failure mode, toughness, and stress-strain behavior of the confined concrete. The initial damage, however, does not change the concrete’s strength decrease rate. An analytical model is calibrated to predict the acidic response of the CFRP-confined concrete, which results in design recommendations based on a performance efficiency factor.