Experimental study on residual flexural strength of macrosynthetic fiber reinforced concrete

The use of fiber concrete technology in the form of flooring to remove thermal rebars and reduce the consumption of structural rebars is popular in the world today. Therefore, it is necessary to evaluate the properties of fibers such as their mechanical properties in concrete, to provide a fiber-concrete mixture design suitable for each project. The mechanical properties of fiber concrete are influenced by various parameters such as the type of fibers, the amount of fiber consumption, the dimensional characteristics, and the physical and mechanical characteristics of the fibers. The main parameter in determining the performance of fiber-reinforced concrete is the ability to provide bending strength after cracking. The purpose of this research is to investigate the effect of different amounts of macro synthetic fibers on the residual strength of concrete. For this purpose, eight concrete mix designs were used with amounts of 2, 4, and 6 kg per cubic meter and a control sample without fibers in two different compressive strengths of 25 and 35 MPa. The method of performing the test is based on the ASTM-C1609. Moreover,, to test the residual strength of fiber-reinforced concrete, the properties of fresh concrete and compressive strength testing were also done. The results of the residual strength test show that the use of macro synthetic fibers increases the load-carrying capacity after cracking, In the compressive strength test, the use of fibers, although it has no effect on the compressive strength value, changes the type of fracture from brittle to ductile.