Effects of Silane Treatment of Steel Fibres on Mechanical Properties and Durability of SFRC

Reinforcing concrete with steel fibres has been investigated with the intention of enhancing the tensile strength and durability of the concrete by resisting microcracking. However, in order to take full advantage of the reinforcing effect of steel fibres, not only to the cracking strength of the matrix, but residually, improvements can be made to (1) the physical bond between the steel fibres and concrete matrix and (2) methods in achieving uniform dispersion of fibres in concrete. Surface treatment of fibres with silane has been proposed as an effective method to improve dispersion of fibres in mortar. The improved dispersion has been attributed mainly to enhanced hydro-philicity of fibres after silane treatment. However, despite the reported promising improvements achieved in terms of dispersion of fibres, the effects of silane treatment of fibres on strength of bond between fibre and concrete as well as the mechanical properties of steel fibre reinforced concrete (SFRC) have not been investigated. This paper proposes a simplified steel fibre silane treatment technique suitable for application in practice. In addition, the effects of silane treatment on strength of bond between fibre and concrete as well as mechanical properties of reactive powder concrete (RPC) including compressive strength, modulus of elasticity, and flexural strength are investigated. Furthermore, the volume of permeable voids and bulk resistivity of concrete are monitored to investigate the effects of silane treatment on durability of concrete and dispersion of fibres in concrete, respectively. The results show a noticeable improvement in the mechanical properties and durability of SFRC after silane treatment of steel fibres.