Seismic Performance of Fibre Reinforced Concrete in the Absence of Bars
Bernard, E. S.
Appears on pages(s):
Reverse-cycle loading, Fibre reinforced concrete, post-crack performance, seismic loading, robustness, conventional reinforcement 236 fib Bulletin 95: Seismic and Special Loading Conditions https
Numerous investigations of the effect of fibre addition on the seismic performance of
conventionally reinforced concrete members have been published. These generally show that
fibres can improve robustness and survivability during reverse-cycle loading, but the dosage
rate of fibre required to achieve significant improvements in performance is substantial.
Recently, pure FRC members have increasingly been used in structures such as tunnel linings,
including both fibre reinforced shotcrete and pre-cast FRC segments. Concerns have been
raised about the absence of data on the seismic resistance of such members given that all
previous research on seismic performance has essentially involved hybrid members
incorporating both steel reinforcing bars and fibres.
The present investigation has focused on the reverse-cycle flexural performance of FRC
members in the absence of conventional steel reinforcing bars. Laboratory testing was
performed on plain, bar-reinforced, and steel fibre reinforced concrete members, and their
performance was compared. The tests indicate that steel fibres provide a small improvement
in flexural capacity under reverse-cycle loading compared to plain concrete, but that the
robustness of pure FRC members is relatively poor compared to steel bar-reinforced members
incorporating steel stirrups. The data suggest that, when used at practical dosage rates, large
hooked-end steel fibres cannot be relied upon to provide seismic performance in flexure
comparable to steel bar reinforced concrete members.