Slip hardening fibres

An additional means for inducing slip hardening bond behaviour is based on densification in the matrix around the fibre, in combination with the presence of fine fillers, as has already been demonstrated in Section 12.2. A demonstration of the efficiency of this means was provided in Section 12.2.2 showing the marked influence of matrix modification in high strength cementitious systems, to obtain bond values with straight steel fibres exceeding 10 MPa. 

Circular Fiber (A) Triangular Fiber (B) Substantially Triangular Fiber (B) 

Reference circular fiber of Diameterd, area A, and Perimeter ltd Triangular fiber of side a, has same area as circular fiber of diameter d, but a perimeter 28% larger. Substantially triangular fiber has about same perimeter as circular fiber of diameter d, but an area only 45% of A. 

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Lin and Li [14] modelled the pull-out resistance of a slip hardening fibre by assuming a linear relation between the interfacial shear stress x and the slip A ... 

The different types of high performance systems will than be treated separately, based on classification in terms of the performance and the strategy to achieve it, to include the following topics monofibre systems with normal strength matrix, monofibre systems with high strength matrix, hybrid FRC, slip hardening fibres and FRC with polymer-cement matrices. 

PVA fibres tend to rupture instead of pull-out of a cementitious matrix, due to the strong chemical bonding and the resulting slip-hardening response during pullout [133]. Li etal. [134] were able to produce composites with an ultimate tensile strain exceeding 4% and a tensile strength of 4.5 MPa, with a fibre volume of only... 

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