Theoretical studies of stress-strain state of concrete under long-term central compression

The results of theoretical studies of stress-strain state of concrete under long-term central compression based on its structural theory are presented. The analysis of determining the stress-strain state on the basis of two most acceptable structural diagrams of concrete is conducted. Positive and negative aspects of the use of these diagrams are given. Based on the analysis, two diagrams have been selected to determine elastoplastic characteristics of concrete under long-term loading based on rheological properties of components. For the diagram of chess spacing of the aggregate in cement matrix, based on equilibrium solutions and the compatibility of deformations, their theoretical values are obtained. Comparisons of the obtained theoretical values of the characteristics of concrete and mortar under a long-term load with the data obtained experimentally are conducted. The results of comparison of experimental and theoretical values indicate the possibility of applying these dependencies to determine elastoplastic characteristics of concrete under a long-term load based on the composition of its components