Standard cement for practice-oriented manufacture of UHPC
The manufacture of UHPC has until now been extremely difficult and complex and can hardly be mastered in conventional precast plants – in ready-mixed concrete plants, nearly impossible to achieve. Dyckerhoff has now developed a cement according to the standards that considerably facilitates the manufacture of UHPC and permits moreover the use of conventional mixing plants and even the usual aggregates. The following article focuses on successfully executed high performance concrete projects. Using selective special pozzolans, this conception has now been further developed into the first special cement, Nanodur® CEM II/B-S 52,5 R, for UHPC without silica fume.
History of high performance concretes with silica fume High performance concretes made with silica fume, based on the model of high density, established themselves in the past decades long before UHPC. Starting point was the need for an appropriate use for electro-filter dusts from the ferro-silica industry in Scandinavia. These industrial by-products, due to the complicated batching they require, are commonly used in concrete production as so-called slurry with 50% solids. For reasons of quality assurance, the batching equipment for this must be integrated into the plant control system. Only...
