The 4C-Packing software is a dedicated tool for concrete mix design. In short, the software calculates the packing density of a set of aggregate fractions. 4C-Packing can also be used to identify the best combination of aggregates to a target grain size distribution curve. In concrete mix design, increasing of the aggregate packing density can lead to a concrete composition with a minimum paste volume and, thus, a minimum cement content. This has a beneficial effect on a number of concrete properties; for example, it helps reduce shrinkage and heat generation during hardening. In addition, the final concrete composition is cheaper and environment-friendly. For the calculations of packing density, 4C-Packing uses a linear packing model that takes into account both the loosening and the wall-effects. The input parameters for calculations include the aggregate’s grain size distribution curve, density and “eigen-packing”. The latter is coefficient that indicates how densely each individual aggregate fraction is packed in a unit volume, i.e. how large a part of the total volume is constituted by solid material. Examples of the software user-interface are shown as follows. Specifically, Figures 1 and 2 highlight the packing diagram and best fit for aggregate skeleton for concrete mixture composed of three aggregates types.
Figure 1: Packing diagram for three aggregates showing iso-packing lines spaced by 0.02.
Figure 2: Best fit for three selected aggregates to the target grain size distribution curve.
The software is delivered electronically and a USB hardware-key is sent by mail.
In addition to the software, the Concrete Centre at the Danish Technological Institute offers a 4C-Packing Training course. The training can take place as an online course or a hands-on course (incl. laboratory tests at DTI’s facilities).