A Comparative Experimental Study on the Flexural Behavior of High-Strength Fiber-Reinforced Concrete and High-Strength Concrete Beams

Abstract

The flexural responses of high-strength fiber-reinforced concrete (HSFRC) beams and high-strength concrete (HSC) beams are compared in this study. A series of HSFRC and HSC beams were tested under pure flexural loading. The effects of the type of concrete, compressive strength of the concrete, and tensile rebar ratio on the flexural behavior of the concrete beams were investigated. The flexural behavior of the HSFRC and HSC beams including the induced crack and failure patterns, load and deflection capacity, crack stiffness, ductility index, and flexural toughness was compared. The crack stiffness of the HSC and HSFRC beams increased with the rebar ratio. For the same rebar ratios, the crack stiffness of the HSFRC beams was much greater than that of the HSC beams. The ductility index of the HSC beams decreased sharply with an increase in the rebar ratio, but the ductility index of the HSFRC beams did not show a clear decrease with increasing rebar ratio. The flexural toughness of the HSFRC beams was greater than that of the HSC beams at higher rebar ratios of 1.47% and 1.97%, indicating that the energy absorption of the HSFRC beams was greater than that of the HSC beams. Test results also indicated that HSFRC developed better and more consistent ductility with higher rebar ratio. In addition, the tested bending strength and sectional analysis results were compared.