STRUCTURAL SAFETY INDICES FOR CONCRETE BEAMS PRESTRESSED WITH FRP TENDONS

One of the main concerns in the design of concrete beams prestressed with FRP tendons is the lack of ductility due to the elastic behavior of FRP tendons Lip to failure. Therefore, the conventional ductility index that describes the inelastic deformation capacity is invalidated in evaluating the performance of concrete beams prestressed with FRP tendons. In this paper, after a brief review of the existing indices Currently used in the design of concrete beams with steel or FRP bars, a new definition of structural safety index (X-factor) for prestressed concrete beams is proposed. The new index is defined as combination of a ductility index, a deformability index and a strength index. It appears to be a suitable measurement of structural performance of concrete beams prestressed with either FRP tendons or steel tendons.