Multi-scale Numerical Simulation Research Of Concrete Based On Random Aggregate

The random aggregate model is established by Matlab in this paper, The numerical analysis model of mortar is established on the meso-scale and the numerical analysis model of concrete is established on the macroscopic scale. The simulation results of mortar model are selected as the parameters of concrete model. The relationship between the growth rate of concrete and cement strength is studied by numerical simulation, laying a foundation for further study of the relationship between macroscopic mechanical properties and microstructure in the numerical model of concrete. And the main contents of this investigation include:(1) The concrete with large quantity of mineral admixtures under compression is studied experimentally. It can be indicated from the research that with the increase of mineral admixtures content the strength of concrete has decreased. Meanwhile, we also can draw that the strength of concrete with mineral admixtures increase slower at first, but faster later than pure concrete.(2) The random aggregate model in this article is established based on the actual aggregate distribution. There is a missing situation about determining the location of the relationship between different aggregate, and the missing is supplemented in this article. Compared to the two finite element mesh methods what were commonly used, more suitable meshing for this article was chose.(3)The heterogeneity characteristics of mechanical parameters on concrete and the phenomenon of damage localization is described by leading weibull probability distribution into the mechanical properties of concrete interface layer. It can be included that the model is better agreement with the experiment by coMParing the numerical simulation and test results. Meanwhile, the failure process under uniaxial compression and splitting tensile could be described from the model, what is the whole process of cracks, extended until through the specimen.(4)Based on the multi-scale theory, porosity is introduced to studying the influence of concrete strength. Analysis is made in quantitative that the concrete strength transforms with the change of porosity. The difference between numerical simulation and experimental results is also analyzed in this paper.