Comparative Investigation of Two Random Medium Models for Concrete Mesostructure

Concrete is intrinsically endowed with randomness on meso-scale due to the random distribution of aggregates,mortar,etc.In this paper,two random medium models of concrete mesostructure are developed and comparative studies are provided based on random field representation approach.In the first place,concrete is considered as a kind of one-phase random field,where stochastic harmonic function is adopted as the approach to simulate the random field.Secondly,in order to represent the stochastic distribution of the multi-phase of concrete such as aggregates and mortar,two-phase random field based on the Nataf transformation and the Hermite polynomials are introduced.Then,the proposed two random medium models are testified by the multi-scale simulation results,specifically,the mean value of the homogenized stress-strain relationship and the damage evolution curve.Meanwhile,the generalized density evolution equation is utilized to measure the consistency of these two random medium models by the probability distribution of damage.