The fibre embedment length was mainly 25 mm, which is a half of the fibre full length.
Although the total pullout energy of fibres with embedment length of, for example, 25 mm, is greater for deformed fibres (hooked, crimped, flat-ended) than for smooth ones, the effect is intangible for relatively small slippage displacement.
As the distribution of fibres in SFRC composite is random, the embedment length at a crack can vary from zero to the half of fibre length.
In the case of crimped fibres the maximum force is almost proportional to the embedment length.
The maximum pullout force for embedment length of 15 mm is close to the one of 25 mm.
Flat-ended fibres with small embedment length have a little or no effect on post crack behaviour in FRC elements or they are not used effectively.
8), which stands for horizontal projection of minimum embedment length, can differ depending on fibre type, concrete strength and the orientation of the fibre.
In the proposed model it is assumed that the maximum force in fibres is determined for embedment length [l.
Region E represents three groups of fibres: 1) fibres parallel or close to parallel to the crack plane; 2) fibres with embedment length smaller than the minimum anchorage length; 3) fibres with inclination angle greater than the critical angle [[theta].
As the fibres in FRC elements have random orientation and they are uniformly distributed through matrix, they have different embedment lengths and inclination angles at the crack.
The tests included specimens with different fibre embedment lengths, concrete strengths, fibre types and orientation angles.