A hybrid beam system of aramid-fibre-reinforced concrete and high-strength concrete

Abstract

ABSTRACT This paper investigates the flexural behaviour of hybrid reinforced concrete (RC) beams having aramid fibre reinforced concrete (AFRC) in the tension zone and high-strength concrete (HSC) in the compression zone. In two series of experimental investigations, the depth of AFRC layer and the concrete strength in the compression zone were varied. The hybrid beams were tested in series 1 to explore the effects of the depth of AFRC layer on load-carrying capacity and flexural toughness. The effects of compressive strength of the concrete in the top half of the hybrid beams on load-deflection behaviour, failure mode and cracking pattern were studied in series 2. The experimental results reveal that the use of AFRC only in the bottom half of the beam enhanced load-carrying capacity and flexural toughness by 62.44% and 87.66%, respectively, compared to the control specimen with no AFRC. The hybrid beam with AFRC-HSC exhibited 5% higher load-carrying capacities, 45% higher ductility and better cracking behaviour than the conventional RC beam. These enhanced structural performances are beneficial for specific purposes such as structures in marine environment where rebar corrosion is the main concern, or structures under extreme loadings where high ductility is required.