Bond stress-slip relationship and development length of frp bars embedded in concrete

Abstract EN

The bond characteristics of reinforcing bars are one of the most critical issues in the design of reinforced concrete structures.

This study presents the bond strength and stress-slip relationships of fiber-reinforced polymer (FRP) reinforcing bars embedded in normal strength concrete.

The study included pullout testing of 40 FRP and steel reinforcing bars embedded in concrete blocks (200 × 200 × 200 mm) with 5db embedment length.

The test parameters were : reinforcing bar material (Glass FRP, Carbon FRP, and Steel) and bar diameter 6.4, 9.5, 12.7), and 15.9 mm GFRP bars– 9.5 and 12.7 mm CFRP bars–10M and 15M steel bars).

The bond strength of GFRP and CFRP reinforcing bars, on average, was 64 % and 71 % that of steel bars, respectively.

The measured bond-slip was modeled using well-known bond slip constitutive laws and employed in the calculation of the development length.

The development length was evaluated and compared with the CSA S806-02, CSA S6-06, and ACI 440.1R-06 provisions.