Nonlinear Analysis of RC Column with Short Lap Splice Length Strengthened by FRP Jacketing

摘要

'Splitting' is one predominant mode of bond failure in substandard RC column with short of lap splice length, causing strength degradation and low ductility when subjected to dynamic load. To prevent splitting bond failure, fiber reinforced polymer (FRP) composites have been used to wrap around lap splice zone. The performance of FRP strengthening was verified by some experimental studies. This paper presents a two-dimensional (2D) nonlinear analytical model for analyzing reinforced concrete (RC) column with short lap splice strengthened by FRP subjected to seismic force. The backbone bond stress versus slip relation was constructed based on previous proposed nonlinear model, and applied to simulate experiment studies on RC column with lap splice strengthened by FRP sheets or prefabricated plates for verification. The model is applicable to both rectangular and circular section, and to both full and partial wrapping. The model is divided into an elastic frame and an assembly of nonlinear springs to represent the elastic portion and the plastic hinge, respectively. The effectiveness of FRP wrapping for strengthening lap splice is taken into account by modifying backbone properties of nonlinear springs. Finally, the model was incorporated into Ruaumoko2D software that serves as a platform to analyze reinforced concrete columns. Furthermore, the proposed nonlinear model can also serve as the design tool to determine the amount of FRP for strength and ductility performance.