Title: Effect of Sustained Loads on Flexural Crack Width in Concrete Beams Reinforced with Internal FRP Reinforcement

Author(s): S.P. Gross, J.R. Yost, and D.J. Stefanski

Publication: Symposium Paper

Volume: 264

Issue:

Appears on pages(s): 13-32

Keywords: crack width; cracking; creep; fiber-reinforced polymer (FRP); serviceability; shrinkage; sustained load; tension stiffening.

DOI: 10.14359/51663258

Date: 10/1/2009

Abstract:
An experimental study was conducted to evaluate the increase in crack width occurring over time in FRP-reinforced concrete as a result of sustained loading. Twelve beams (eight GFRP, two CFRP, and two steel-reinforced) were maintained under a constant sustained service load for nearly three years. Three flexural cracks were monitored on each beam over the duration of the test. The observed increase in flexural crack widths over the study was greater in the FRP-reinforced specimens than in the steel-reinforced specimens. On average, flexural crack widths in FRP-reinforced concrete specimens were observed to double over one year of sustained loading. A simple design approach, based on modification to the existing ACI 440 (2006) crack control procedure, is proposed to account for this observed increase in crack widths with time.