Bond strength of glass FRP rebar splices in beams under static loading

Abstract

This paper presents the preliminary findings of a research programme to characterise the strength of rebar splices in reinforced concrete members containing FRP reinforcement. The key parameters are the diameter of FRP rebar and the embedment length. This is the first paper, originating from an extensive ongoing investigation being carried out by the authors, to gain a better understanding and develop appropriate design procedure that reflect the changes in bond strength caused by the use of FRP rebars instead of conventional steel rebars. A total of 16 reinforced concrete beams were tested in flexure. The effects of bar size (12.7 and 15.9 mm) and splice length (0.6, 0.7, 0.9, 1.3 and 1.6 l d) on the bond strength were critically evaluated. The bond development length ( l d) was calculated according to the relevant ACI Building Code (ACI 318M-95) requirements for steel rebars in concrete. The test results indicate that a modification factor of 1.3 is necessary for the bond development length of glass FRP rebars in order to achieve an adequate tension lap splice length.