Evaluating UHP-SFRCs Performance under Flexural and Tensile Loadings and Aggressive Environment by Assessing the Applicability of Different Constituent Materials in UHPC Production

Ultra-High Performance Concrete (UHPC), known for its superior mechanical and durability properties, is an appropriate material for different applications such as building and bridge construction. Investigating the possibility of UHPC production using available materials is an engineering challenge. This paper evaluates the applicability of some materials in making UHPC and the effectiveness of several parameters on the compressive strength of UHPCs. Then, by choosing the mixture yielding the highest compressive strength, the durability and mechanical properties of the mixture with 0-2.5% crimped steel fiber are investigated. The tests include compressive strength, flexural and tensile parameters, length change, rapid chloride ion migration, sorptivity, porosity, and sulfate resistance. The results reveal that the pozzolanic activity of silica fume and its synergetic effect with glass powder lead to the highest compressive strength. Moreover, it makes it possible to easily obtain a strength higher than 150 MPa. Utilization of 2.5% crimped steel fiber in UHPC mixtures remarkably enhanced mechanical performance so that the flexural and tensile strength were increased by about 95% and 25% compared to the plain UHPC, respectively. However, the incorporation of fibers increased the UHPC permeability.