Influence of synthetic fibers on the seismic behavior of reinforced-concrete circular columns: Fid-Bau Portal

Influence of synthetic fibers on the seismic behavior of reinforced-concrete circular columns

Rivera, Jésus Emilio / Eid, Rami / Paultre, Patrick

Highlights • Seismic behavior of synthetic fiber reinforced concrete (SNFRC) columns is examined. • Experimental study was conducted on large scale reinforced concrete columns under constant axial and reversed lateral loading. • The influence of the synthetic fibers on the ductility of RC columns with different hoop spacings is presented. • Reduction in the transverse steel reinforcement amount can be achieved when using SNFRC. • The use of SNFRC with small hoop spacings (<75 mm) can result in a lower ductile behavior and thus is not recommended.

Abstract The addition of discrete fibers to the concrete mixture to enhance its toughness and tensile strength is well acknowledged. Studies have also shown that fiber-reinforced concrete (FRC) can be favorable for its enhanced behavior in compression. This behavior, which is attributed to the confinement action of the fibers, is, in general, superior in terms of strength and ductility, compared to plain concrete. Reversed cyclic loading in flexure under constant axial load of large scale synthetic fiber-reinforced concrete columns is scarce as opposed to steel fiber-reinforced concrete columns. This paper presents an experimental study on the behavior of large-scale synthetic fiber-reinforced concrete columns with hoops transverse steel reinforcement under constant axial load and reversed flexure simulating seismic loading. The results from this study show slightly improved cyclic behavior compared to results obtained on similar columns reinforced with spiral transverse reinforcement. Enhanced behavior of synthetic fiber-reinforced concrete is achieved for practical transverse steel reinforcement spacings ( $⩾ 75$ mm). In this case, similar ductile behavior of a reinforced-concrete column can be reached with a reduced amount of transverse steel reinforcement and the inclusion of synthetic fibers with an aspect ratio of 50–100 to the concrete mixture. Difficulty in placing synthetic fiber-reinforced concrete in very congested columns precludes its use in columns with hoops or spiral spacing less than $75 mm$ until self leveling concrete with large amount of synthetic fibers is developed.