Ultra-high performance fibre-reinforced cementitious composite with steel microfibres functionalized with silane

This paper explores the effect of fibre functionalization with tetraethoxysilane (TEOS) in the microstructure and mechanical property of ultra-high performance cement composites with steel fibres. Fibres treated with three concentrations of TEOS were evaluated by pullout tests and SEM/EDS analysis. Mixes with treated fibres showed up to 35.6% increase in bond strength and up to 49.5% reduction in the crack opening at the peak pullout load in comparison with reference mixes containing untreated fibres. The Si/Ca ratios in the fibre-matrix transition zone increases with the increment of the concentration of TEOS in the treatment of the fibre. This indicates an increase of C-S-H at the interface that justifies the enhanced mechanical performance.