Manufacturing and characterization of high-performance fiber-reinforced concrete with locally available materials

Abstract

Commercial ultrahigh-performance fiber-reinforced concrete (UHPFRC) is expensive because of its use of complex materials and proprietary mix designs, which are often not locally available. In this study, high-performance fiber-reinforced concrete (HPFRC) using locally available materials and conventional technologies was developed for producing prefabricated structural elements. Two different types of steel fibers were analyzed. The developed HPFRC mixtures were characterized by using their compressive strength, modulus of elasticity, stress–strain relationship under uniaxial compression, and tensile strength. The tensile stress–strain relationship of the HPFRC specimens was also determined using various methods, including the modified double edge wedge splitting (DEWS) method proposed in this paper and a back-calculation approach involving finite element modeling. The HPFRC achieved a compressive strength of 100 MPa at 28 days and 130 MPa at 170 days after casting. By using steel fibers with a low aspect ratio, the compressive strength was reduced by up to 17%. Additionally, the developed concrete with 2% steel fibers did not exhibit compression softening behavior. The tensile stress–strain relationships of the HPFRC depend on the method used, and the results show that an inverse analysis from the four-point bending test on unnotched prisms provided a more accurate tensile property for the UHPFRC. The HPFRC with 2% steel fibers exhibited flexural-hardening behavior and met the minimum post-cracking tensile strength required for commercial UHPFRC. This resulted in ductile behavior in tension, making it suitable for use in structural members without the need for reinforcing steel.