4.5.1 Wall-effect of the steel fibres
The K-Index links the actual with the virtual packing density of a monodisperse fraction
and indicates the compaction level (Equation 4.13). De Larrard [1999] proposed Kindices
for different compaction levels: pouring resulted in a K-index of 4.1, sticking with
a rod in 4.5 and vibration in a K-index of 4.75. According to De Larrard [1999], the
compaction index K of a monodisperse fraction links the virtual and the actual packing
densities by Equation 4.13; the virtual packing density of the fibres becomes: