Flexural response of polypropylene fiber reinforced concrete using the fiber composite model

Resumo

In the last decades, several laboratory tests have been carried out to investigate the mechanical
behavior of fiber-reinforced concrete (FRC), especially regarding their flexural response for several structural
applications in Engineering. Modern developments concerning these materials have improved the number of
numerical models capable of predicting mechanisms at the material scale and the load-displacement behavior of
the composite. Therefore, the preliminary stages of advanced cement material design can profit from
mathematical models since the numerical experiments can consider different material working conditions before
prototyping. This paper proposes the numerical modeling of polypropylene fiber reinforced concrete beams
using a mesoscale formulation called the fiber composite model. This model consists of the coupling of uniaxial
fiber finite elements with continuum cementitious elements through cinematic constraint equations, where the
fiber degrees of freedom are eliminated at the element level. Additionally, a cohesive zone with a continuum

damage behavior is inserted into the formulation to simulate the post-cracking material flexural response. Three-
point bending experimental tests reported in the literature are modeled. The results show good agreement

between the experimental references and the reinforced cohesive element model to predict fracture patterns for
FRC beams.