Improving the tensile strength of reinforced concrete: evaluating the impact of different fiber additives through numerical and experimental analysis

Abstract

This research investigates the effect of various fibers on the strength and flexibility of concrete from an educational perspective. In this research, the use of additives including types of fibers (macrosynthetic fibers, polypropylene, and glass fibers) which make up 1% of the volume of hybrid concrete is taught. The combined addition of these fibers to create the hybrid reinforced concrete with high tensile strength and plasticity is discussed in this education. The tensile strength results obtained from direct and indirect methods have significant differences. In the concrete laboratory, multiple experiments were carried out to determine the best fiber composition using two different types of fibers. The experiments included direct tensile testing using the compressive-to-tensile force conversion (CTFC) method, which is a new approach, and indirect tensile testing using the Brazilian disk method. The loading rate for the tests was 1 kg/sec. The average tensile strength was 3.3 MPa, and the average compressive strength was 35 MPa. The Young’s modulus was measured to be 20 GPa. The results showed that macrosynthetic fibers were more effective in increasing the concrete’s tensile strength compared to other combinations. The tests performed on the effects of combining glass fibers with macrosynthetic fibers compared to combining macrosynthetic fibers with polypropylene show a more effective tensile strength. In this article, the direct tensile strength of concrete samples is evaluated by introducing an innovative tensile test device with a ring-shaped sample. The results obtained from this new device have been numerically compared with the uniaxial direct tension method proposed by ISRM. The educational measures of this new knowledge regarding concrete additives and performing innovative tensile strength tests and comparing them with each other provide a detailed understanding of concrete strength evaluation.