The aim of this research is evaluating the strength properties of high strength fiber-reinforced concrete depending on replacement ratio and aspect ratio. As a part of producing SUPER concrete which has high ductility with fiber-reinforcement, both high mechanical properties and improved ductility should be achieved. Hence, mainly mechanical properties of the concrete with fiber was studied and from the results of the experiment, it was not shown the significant influence on compressive strength with fiber replacement ratio and aspect ratio, while as the fiber replacement ratio and aspect ratio were increased, the tensile and flexural strengths were improved. Especially, for fiber aspect ratio of 100, when the fiber replacement ratio was 2%, the most desired ductility was obtained.

Keywords: Fiber-reinforced concrete, Replacement ratio, Aspect ratio, SUPER concrete.