Method for predicting ion diffusion coefficients of damaged cement based composite materials

Abstract

The invention discloses a method for predicting ion diffusion coefficients of damaged cement based composite materials. According to the method, regarding the microcosmic structure of damaged cement based composite materials which are discretized into a series of cube three-dimensional space lattices with equal size, each pair of adjacent cube three-dimensional space lattices are used as a lattice diffusion unit, wherein ion diffusion ability exists between each pair of adjacent cube three-dimensional space lattices, all the lattice diffusion units combine together to form a three-dimensional lattice ion transmission network, and each lattice is used as a diffusion node. Damage cracks are processed as hole phases, an ion diffusion matrix equation is established by using diffusion matrix equations between every two adjacent diffusion nodes in the three-dimensional lattice ion transmission network and combining ion concentration boundary conditions, solution is carried out on the ion diffusion matrix equation to obtain ion concentration distribution under a steady state, and finally the ion diffusion coefficients of the damaged cement based composite materials is obtained. The method for predicting the ion diffusion coefficients of damaged cement based composite materials can accurately predict ion diffusion ability change rules of the damaged cement based composite materials under the influences of freeze thawing, loading, air shrinkage and other conditions.

Description

technical field [0001] The invention relates to a method for predicting the ion diffusion coefficient of damaged cement-based composite materials, and belongs to the field of cement-based composite materials. Background technique [0002] The transport performance of cement-based composites is a key factor related to the durability and service life of civil engineering materials. When the material is affected by factors such as external loads, freeze-thaw cycles, and drying shrinkage, the internal defects of the material or the existing defects increase in size and number, which is manifested as the generation and development of micro-cracks or changes in porosity, making the material Diffusion, The transport properties such as permeation and electromigration increase, resulting in reduced durability and shortened service life of the material. Therefore, accurate prediction of changes in transport properties of damaged cementitious composites is of paramount importance. ...

AI Technical Summary

Problems solved by technology

This analytical model is simple to calculate, but the basic assumptions are too ideal, and it is difficult to realize the change of the transmission performance of cement-based composites under the single or multi-factor coupling effects such as freeze-thaw, load and drying shrinkage.

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