A FRACTURE MECHANICS MODEL FOR THE ANALYSIS OF REINFORCED FRC BEAMS

摘要

In previous works it has been shown how the bridged crack model can simulate the mechanical behavior of concrete beams having both fiber and ordinary steel bars reinforcements. The model was including a general constitutive law for the fibers, a rigid- plastic model for the bars and an indefinitely elastic behavior for concrete. The interaction of the fibers with the reinforcing bars is accounted for by evaluating the width of the cohesive zones along the crack length. In the present work a methodology for introducing the evaluation of the maximum compressive stress is presented and a new parameter, the maximum nondimensional compressive stress, appears in the design of the reinforced FRC cross section to avoid crushing failure. In the paper the variation of the model response with the governing parameters is illustrated. Steel bars yielding or concrete crushing collapse mechanisms are individuated through maps.