FINITE-ELEMENT ANALYSIS OF PARTIALLY PRESTRESSED STEEL FIBER CONCRETE BEAMS IN SHEAR

This paper presents a finite element formulation for the modeling of the behavior of partially prestressed steel fiber concrete beams in shear. Based on a secant modulus approach, the formulation treats steel fiber concrete as an orthotropic material, characterized by appropriate constitutive relations in the principal compressive and tensile directions, An experimental program with the partial prestressing ratio, the shear span:effective depth ratio, and the volume fraction of steel fibers as test variables was carried out and the deflections of the beam, concrete, and steel strains were monitored and compared with the results of the finite element analysis. The finite element formulation was found to predict the deformational characteristics and the ultimate load of the test beams well. Steel fibers were observed to improve the beam stiffness after the occurrence of first shear crack and to enhance the shear strength of partially prestressed concrete beams significantly.