Bond-flexural behaviour of structural nano-synthetic fibre-reinforced cementitious composites

Prior studies have shown that the bond properties of structural nano-synthetic fibre in a cement matrix improved as the shape of the fibres became more three-dimensional. The maximum pull-out resistance strength increased but improvement of interfacial toughness did not follow due to fibre fracture. In this study, cementitious composites containing structural nano-synthetic fibres that improved the bond properties were examined for their flexural properties. The relationship between the bond and flexural properties were studied as a function of fibre volume fraction and shape; the straight type of fibre was also examined as a control. It was found that the flexural toughness increased with increasing fibre volume fraction. For the twisted type of fibre, the maximum residual flexural strength decreased with increasing crack mouth opening. However, the twisted + crimped type of fibre displayed stable post-peak behaviour with continuously increasing residual strength.