A stochastic second-order and two-scale thermo-mechanical model for strength prediction of concrete materials

摘要

A stochastic thermo-mechanical model for strength prediction of concrete is developed, based on the two-scale asymptotic expressions, which involves both the macroscale and the mesoscale of concrete materials. The mesoscale of concrete is characterized by a periodic layout of unit cells of matrix-aggregate composite materials, consisting of randomly distributed aggregate grains and cement matrix. The stochastic second-order and two-scale computational formulae are proposed in detail, and the maximum normal stress is assumed as the strength criterion for the aggregates, and the cement paste, in view of their brittle characteristics. Numerical results for the strength of concrete obtained from the proposed model are compared with those from known experiments. The comparison shows that the proposed method is validated for strength prediction of concrete. The proposed thermo-mechanical model is also employed to investigate the influence of different volume fraction of the aggregates on the strength of concrete. Copyright (C) 2016 John Wiley & Sons, Ltd.