4.1 Introduction
Chapter 4 reports on the background and on experimental and numerical studies on
packing density. After a brief introduction into the literature and a description of the
Compressible Packing Model (CPM), experimental as well as numerical results are
discussed. The porosity of the granular skeleton (aggregates and steel fibres) determines
how much paste is required to fill its interstices. Two questions are discussed in this
chapter: How to decrease the porosity as much as possible and how to predict it.
Experimental studies were performed, which aimed at optimising the granular skeleton.
Results of packing experiments are compared with numerical predictions of the CPM.
The required input parameters to conduct simulations with the CPM are experimentally
determined. Five approaches are compared to include the fibres into the CPM; the
accuracy of the predictions is calculated. The approach with the best accuracy is applied
to predict the packing density of SCFRC.