Effect of lap splice of GFRP reinforcements on development length

Abstract

In the existing international FRP reinforced concrete codes ACI 440.1R-15 and CSA S6-10, equations for both development length and lap splice length are proposed. However, as a result of the experimental studies in the literature, it is stated that these equations give extremely safe results. Usually the lap splice length is determined by multiplying the development length by a constant coefficient. However, due to the differences between the coefficients recommended in the literature and regulations, it is unclear to what extent the development length is affected by the lap splice length. In this study, the effect of splice on development length is examined by accounting for the surface properties of GFRP and steel reinforcement. A total of 4 hinged beam specimens with no lap splice and 4 hinged beam specimens with lap splice, prepared with sand coated, wound and ribbed GFRP and steel reinforcement types, were tested under 4 point bending. The study yielded to the conclusion that the splice in steel reinforcement increases the development length, while surprisingly decreasing the development length in the FRP reinforcement.