Micromechanics And Chloride Diffusion Numerical Simulation Of Recycled Aggregate Concrete

In general, it also contains a part of the waste brick besides waste concrete in construction waste and it is difficult to classificate them completely, so in the research on the properties of the recycled aggregate concrete, it is necessary to study the effect of the content of brick in recycled aggregate concrete on its performance.Given that the study of the influence of the brick content on the recycled aggregate concrete performance is still not mature enough and most are based on the macro research, in this article, the recycled aggregate concrete is considered as a composite material consisting of the new and old mortar matrix, the recycled coarse aggregate(recycled coarse aggregate concrete and brick) and the old and new interfacial transition zone on meso-level. First, the number of the aggregate model is obtained by the concrete optimal gradation theory. Then, based on monte-carlo method, it should generate the geometric model of the ordinary aggregate combining with MATLAB program algorithm, the principle of which is simple and clear. On this basis, the simplified model of recycled concrete is put forward by improving the geometry model of random aggregate of ordinary concrete combining with the characteristics of recycled concrete. The establishment of typical two-dimensional circular, three-dimensional ball model is completed in the ANSYS. Last, it carries on the numerical simulation of micromechanics and chloride diffusion properties of the recycled aggregate concrete on meso-level by using ANSYS numerical simulation software.1. On the micromechanics of the recycled aggregate concrete, it reveals the failure essence of the recycled concrete, and comes to a conclusion that the tensile performance and the compressive performance of the recycled concrete become lower along with the increase of the content of recycled brick in recycled aggregate.2. On the chloride diffusion properties of the recycled aggregate concrete, the results obtained from the numerical simulation indicate that the distribution of chloride concentration is non-uniform within the recycled aggregate concrete and the chloride concentration declines in waves along the diffusion depth. The brick content in the recycled aggregate concrete has a certain degree of influence on the permeability of the chloride ion. The permeability of the recycled aggregate concrete shows the tendency of increase along with the increase of the content of recycled brick in recycled aggregate, in other words, the durability becomes worse and worse.Through the above conclusion, we know that the mechanical properties and permeability performance of recycled concrete are distinct from ordinary concrete and the brick content in the recycled aggregate concrete has a greater impact on its mechanical properties and permeability performance, so it is necessary to try your best to isolate abandoned brick in the production of recycled concrete and strengthen improvement on some basic properties of recycled concrete in order to make its high-performance.