Self-compacting concrete must be capable of flowing easily. Without further assistance, the concrete is supposed to fill a formwork of any shape without leaving any cavities, to enclose the reinforcement and to deaerate and level itself. At the same time, the properties of the hardened concrete must be as good as those of a standard concrete. The spherical grain shape of the fly ash improves the embedding of the mineral grains in the concrete so that they can be transported more easily.