Entwicklungsprinzipien und technische Grenzen der Herstellung zementarmer Betone

This paper explains the principles of proportioning ecologically sustainable, cement reduced concrete mixtures. It attempts to provide an answer to the question of how the cement content in concrete can be reduced without adversely affecting key characteristics, such as consistency and compressive strength. The central element of the proposed algorithm for mixture development consists of particle packing models, with which the water demand of the granular mixture of cement, stone dust and aggregate can be minimized. In this report a combined approach, consisting of the particle size distribution model of Funk and Dinger and the CIPM model of Fennis, is proposed. The experimental investigations carried out suggest that it is possible to reduce the binder intensity (the demand for binding material to produce 1 MPa of compressive strength in 1 m³ of concrete) of the concrete by a factor of ca. 3 as compared to normal concrete when following this approach. The experimental investigations also suggest that the workability of the mixtures can be estimated well by the quotient function between the actual particle packing density and a theoretical maximum particle packing density of the granular mixture.