Model of Behavior at Pulling of the Reinforced Concrete of Waved Fibers

The modeling of the behavior in pulling of the reinforced concrete of waved fibers (to variable geometry), is based on the study of the behavior of the fiber in the concrete matrix. Writing the energy equilibrium of an undulating fiber at the time of the sliding, the movement is governed by a differential equation. The pull-off strength of the fiber is obtained by integrating this one on the length anchored of the fiber, the phenomenon of friction fiber-concrete matrix, the influence of the radial constraints (due to the undulation) and the case of the possible plasticization of the steel constituting the fiber, one considered in the modeling. A solution to the problem of the modeling of the adhesion waved fiber - concrete matrix was proposed bringing to light the evolution of the constraint of adhesion (tu) according to the "t" anchoring. This modeling is introduced in an effort relation-opening of the cracks, and then a passage to the law (constraint –deformation) was made by modifying this relation. Finally for every modeled parameter (adhesion, constrained-deformation in pulling and pickets submitted to a compound flexion), a calculation confrontation /test was been executed. The results of the confrontation are rather satisfactory.