Numerical Modelling of Concrete Pressure on Vertical Formworks

Recent times have seen an advent in the use of high workability concretes as they can be placed with no or minimum vibration, and they provide better surface finishes. There is a lack of information on the resulting formwork pressure distributions during the construction phase, as the provisions of the present standards do not contain pressure values for new age concretes like Self Compacting Concrete etc. In order to assess these pressures, a numerical model has been developed which considers the time dependent material behaviour of concrete and the interaction between fresh concrete and the formwork. Parametric studies carried out for the estimation of formwork pressures for vertical walls of varying widths and heights cast with different types of concrete at different rates, indicate a good correlation with pressures obtained from performed experiments. Furthermore, the model results were compared with values from the German code, DIN 18218, and it is established that the provisions of the code are on the conservative side