Description of work
Currently, the ready mix and prefab industry use SCC mainly for uncomplicated horizontal applications e.g. slabs on grade, foundations and facade elements. Horizontal castings, though not trivial, are much easier to control than castings into vertical and complex shaped formworks. Here, there is need for fundamental research on the effect of material properties, casting technique and boundary conditions on the final structural quality.
The purpose of this WP is to determine the effect of rheological properties and casting technique on the execution of unique concrete structures with SCC. The research will include modelling of flow and experimental trial castings for verification. Models will be developed within the framework of computational fluid dynamics in order to simulate the complex free surface flow of SCC. The models will be used to make the correct choice of rheological properties and casting technique for the individual casting in order to obtain complete form filling, no segregation, a minimum formwork pressure, and the required surface finish quality and fibre orientation.
The choice of rheology forms the basis for the mix design optimisation process. Models will be developed in order to predict the rheological performance based on the mix composition. The models will be based on the composite theory considering solid particles (aggregate) and/or fibres suspended in a fluid matrix phase (cement paste). Experiments will be carried out to verify the model prediction.
DTI will undertake the research using the automatic DTI mixing plant to prepare batches of up to 750 litres with different rheological properties. DTI will also utilise its robot facilities to manufacture the selected unique small scale form works for verification. The work is followed up by full scale verification in close cooperation with the industrial partners (WP7).
The detailed methods to be used in this WP will be drawn up by DTI who will coordinate this work.
WP leader: Danish Technological Institute