Flexure Behaviour the Concrete Beams Reinforcement with Polymer Materials

Abstract

Improvement of flexure behavior using the polymer materials is one of the very important factors in analyzing the concrete elements, especially concrete beams. In this case we analyze two different cases: • Improvement using the polypropylene microfibers in ready mix concrete • Improvement using the carbon fibers in external reinforcement In both case studies we used three-point-load experimental beam-bending tests for: three conventional RC beams (referent beams), three RC beams with polypropylene fibers and three RC beams with carbon fibers. All results concern comparing the effect of fibers on improvement of energy capacity of concrete elements, and increasing the bearing capacity of concrete beams. One of the most important values based on the behavior of the structure is ductility. The ductility is a structural design requirement in most design codes. The traditional definition of ductility cannot be applied in structures reinforced with FRP reinforcement. Several methods, such as the energy based method and the deformation based method have been suggested to calculate the ductility index for FRP reinforced structures. Furthermore the behavior of RC beams is analyzed with the help of cracks, their position and width under the loads.