„Anwendungsorientierte Optimierung der UHPC-Rheologie“

Initial applications of UHPC for precast concrete parts and the investigations carried out so far within the framework of SPP 1182 have shown that, despite the almost flowable consistency of the UHPC, the formwork was not always filled homogeneously and/or the concrete could not be sufficiently de-aerated. The causes are the large amount of densely packed, highly dispersed fines, the large amount of superplasticizer and the mixing process, which together determine the rheological behavior. For the practical use of UHPC, it is indispensable to adapt the flow and deaeration behavior during concrete design individually to the respective components and the manufacturing conditions. For this purpose, the partial knowledge gained so far, mainly on standard mixes, must be combined, placed on a broader material basis and finally linked to the various applications by means of test methods suitable for practical use. Up to now, complex mixture tests have been necessary in each individual case, which is time-consuming, expensive and not always successful. The ultimate goal is a classification system for fresh concrete which, as with normal concrete and SCC, makes it possible to set the processing properties in the suitability test on the basis of objective characteristic values and to monitor them during production.