Experimental investigation on effects of hybrid fibers on rheological, mechanical, and durability properties of high-strength SCC

The aim of the present study is to investigate the effects of using hybrid fibers on rheological, mechanical and durability properties of the high-strength self-consolidating concrete (SCC). For this purpose, two types of fibers including hooked-end steel fibers and polypropylene fibers were used. In this study, a total of eleven mixtures were used: one as a control mix, one containing 0.5% steel fibers, four containing 0.5% hybrid fibers (steel and polypropylene), one containing 1.0% steel fibers and the four containing 1.0% hybrid fibers (steel and polypropylene). For investigating the rheological properties, slump flow, J-ring and V-funnel tests were performed. Mechanical properties were studied by conducting compressive strength, splitting tensile strength, modulus of rupture and flexural toughness tests. Moreover, ultrasonic pulse velocity conducted as a non-destructive test to assess the quality and integrity of the concrete. Durability properties of this type of concrete were evaluated by electrical resistivity tests. Effects of fibers in rheological and mechanical properties have been studied and compared.