Study of Dimensioning Aspects of FRC Based on the Beam Flexion Theory

The fiber reinforced concrete (FRC) have a higher load capacity in the post-cracking stage, however, this increase only occurs if the concrete is dosed and applied properly and, for this, there are standards that establish design aspects for use of the FRC. However, in these documents, the portion of the resulting resistant strength of the fibers is not fully described in their equations and is determined for specific situations. Therefore, and with the objective of obtaining the positioning and the resultant of the fibers of a model of fluid concrete reinforced with fibers, this work presents a study related to the determination of the resultant of the fibers in the stretched part of the concrete. This determination was obtained based on the bending theory in beams, through the three-point bending test standardized by EN 14651 (2007) [8], where both beams with steel fibers and polymeric fibers were used. From this, the equation obtained analytically was compared with those determined by international codes and it was realized that, when comparing the three methods used, the intermediate value corresponded to the determined analytically, where the results showed variations due to the different forms of arrangement that each method uses.