Document Type

Concrete structures paper

Publication details

Mohamed Ali, MS & Sheikh, AH 2014, 'Mechanics based models for ductility of fibre reinforced concrete beams', in ST Smith (ed.), 23rd Australasian Conference on the Mechanics of Structures and Materials (ACMSM23), vol. I, Byron Bay, NSW, 9-12 December, Southern Cross University, Lismore, NSW, pp. 307-312. ISBN: 9780994152008.

Peer Reviewed



Steel fibre reinforced concrete (SFRC) is increasing in popularity as a material for structural design, due to an improved resistance to cracking and crack propagation, resulting in increased strength and toughness in flexure. However, there is a limited scope of application of fibre reinforced concrete (FRC) fuelled by a lack of understanding in FRC design for structural members. This research investigates the affect that adding steel fibres to a concrete matrix has on the moment-rotation (M-R) and load-deflection (Pm-δm) responses of reinforced concrete (RC) beams. This includes the development of a numerical partial interaction (PI) reinforcement bar (rebar) load-slip (P-Δ) model, numerical M-R models and the determination of a Pm-δm relationship using an analytical method. The PI model, which can incorporate any generic bond stress-slip (τ-δ) relationship, simulates the bond and cracking behaviour of rebars embedded in SFRC. This allows the determination of the crack spacing, crack width and the longitudinal rebar P-Δ relationship. The P-Δ relationship is required to determine the M-R response up until failure. It was found that the inclusion of fibres into the concrete matrix results in more, closely spaced cracks with reduced crack widths, due to the fibres restraining crack growth.