Experimental study on bond strength of fiber reinforced polymer rebars in normal strength concrete

Abstract

The bond behavior of reinforcing bars is an important issue in the design of reinforced concrete structures and the use of fiber reinforced polymer (FRP) rebars is a promising solution to handle the problems of steel reinforcement corrosion. This study investigates the bond characteristics of carbon and aramid FRP (CFRP and AFRP) bars embedded in normal strength concrete. A pullout test was performed on 63 normal strength concrete specimens reinforced with FRP and steel rebars with different embedment lengths and bar diameters. The average bond stress versus slip curve is plotted for all specimens and their failure modes are identified. The effects of the embedment length and diameter of an FRP rebar on its bond strength are examined in this work. The bond strengths obtained from the test results are compared with the predictions by the bond strength equation proposed by Okelo and Yuan (2005), and its validity is evaluated.

Keywords:

• bond strength
• fiber reinforced polymer rebars
• pullout test
• bond stress-slip curve
• embedment length
• bar diameter

Acknowledgment

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2011-0016332).