Stress–Strain State and Strength of Fiber-Reinforced Concrete Beams with Basalt, Steel, and Polypropylene Fibers

Fiber-reinforced concrete has proved to be viable in improving the mechanical characteristics of structural elements to the flexural and shear stresses. The concrete cubes, prisms, and cylinders were standardized and cast and cured after 28 days to assess the baseline mechanical characteristics. Beam specimens were made of different types of fibers, lengths, and different volumetric contents and then subjected to controlled shear tests in which the crack initiation, propagation, and deformation were accurately measured. The experimental data proved that the addition of fibers was highly beneficial in terms of the mechanical performance of concrete. Basalt fibers enhanced compressive strength by up to 20.8 percent and tensile strength by 30.8 percent, whereas steel fibers had the best flexural strength with a maximum compressive and bending strength of 47.2 MPa and 6.56 MPa, respectively, at optimum dosage. Polypropylene fibers also improved performance, but in a lesser manner. The fiber addition served well to reduce the width of cracks and retard crack propagation, thus enhancing load-bearing capacity. These results show that dispersed fiber reinforcement that uses steel and basalt fibers is a practical solution to improving the dispersion of concrete in terms of durability and load-bearing capacity. The research will help guide the selection of fiber and the content in the reinforced concrete work to offer more robust and sustainable solutions to building.