Early-age effective elastic properties of cement-based composites

Abstract

The problem of the prediction the early age effective elastic properties of cement-based composites is one of the most important and at the same time complicated problems of concrete technology. Cement-based composites consist of a large number of randomly distributed phases with different geometric shapes and sizes at each structural level.Currently, there are two common approaches to modeling the effective elastic properties of cement-based composites –analytical andnumerical homogenization. Most of the researches of the effective properties of cement-based composites focused their attention on the effective medium theory as a part of analytical homogenization, in which all composite phases are considered as spherical inclusions leading to relatively simple computational models for prediction. This significant assumption affects the accuracy of predicting the effective properties, since it is awell-known fact that the real geometric shape of most phases of cement-based composites differs from spherical. One of the drawbacks of the effective medium theory is that solutions for non-spherical inclusions can only be received for a regular geometric shape representing an ellipsoid.At the same time, one of the advantages of numerical homogenization based on finite element analysis is the possibility of calculating elastic properties for an arbitrary geometric shape of inclusions.The purpose of the study is multiscale modelling the effective elastic properties of cement-based composites, using a combination of analytical and numerical homogenization, considering the geometric shape of the phases at each heterogeneous level, close to their real shape in the structure of composites.