Procedure for calculation of pressure of newly laid self-compacting concrete mixture on formwork

The article discusses the problem of reliability of calculation of pressure value of newly placed self-compacting concrete mixture on formwork. This problem is especially relevant when concreting structures of high height. Results of scientific researches of dependence of value of lateral pressure of concrete mixture on formwork on rheological, technological factors and parameters of concrete structure are analyzed. A comparison of the methods for calculating the lateral pressure of freshly placed concrete mixture used in standardization documents in the Russian Federation and in other countries is given. Based on the generalization of scientific data and comparison of the above methods, an original method for calculating the pressure of a self-compacting concrete mixture on the formwork is proposed. The reliability of the developed procedure is checked using two different examples (based on the data of real concreting of structures). In the first case, to assess the reliability of the proposed method for calculating the pressure of the freshly placed concrete mixture, the data on the measurement of the actual pressure performed during the construction of the inner containment of the Belarusian NPP were used. In the second case, data on concreting the structure in fixed steel fibre concrete formwork were used. The proposed method has shown its applicability based on the results of comparison with the actual values. The presented calculation method can be recommended for use in the development of technological regulations for concrete works when using self-compacting mixtures, as well as justification of the stiffness and strength of formwork systems.