文献类型：期刊文献

英文题名：Brownian Motion Simulation for Estimating Chloride Diffusivity of Cement Paste

作者：Zhang, Congyan[1];Li, Xiang[1];Chen, Feng[2];Wang, Xudong[1];Zheng, Jianjun[3]

机构：[1]Shaoxing Univ, Yuanpei Coll, Shaoxing 312000, Peoples R China;[2]Zhejiang Ind Polytech Coll, Sch Architecture & Engn, Shaoxing 312000, Peoples R China;[3]Zhejiang Univ Technol, Sch Civil Engn, Hangzhou, Peoples R China

年份：2023

卷号：16

期号：5

外文期刊名：MATERIALS

收录：SCI-EXPANDED(收录号：WOS:000947715000001)、、EI(收录号：20231113728086)、Scopus(收录号：2-s2.0-85149863445)、WOS

语种：英文

外文关键词：chloride diffusion coefficient; cement paste; Brownian motion; numerical simulation

外文摘要：Chloride ion diffusion properties are important factors that affect the durability of cementitious materials. Researchers have conducted much exploration in this field, both experimentally and theoretically. Numerical simulation techniques have been greatly improved as theoretical methods and testing techniques have been updated. Researchers have modeled cement particles mostly as circular shapes, simulated the diffusion of chloride ions, and derived chloride ion diffusion coefficients in two-dimensional models. In this paper, a three-dimensional random walk method based on Brownian motion is employed to evaluate the chloride ion diffusivity of cement paste with the use of numerical simulation techniques. Unlike previous simplified two-dimensional or three-dimensional models with restricted walks, this is a true three-dimensional simulation technique that can visually represent the cement hydration process and the diffusion behavior of chloride ions in cement paste. During the simulation, the cement particles were reduced to spheres, which were randomly distributed in a simulation cell with periodic boundary conditions. Brownian particles were then dropped into the cell and permanently captured if their initial position in the gel fell. Otherwise, a sphere tangential to the nearest cement particle was constructed, with the initial position as the center. Then, the Brownian particles randomly jumped to the surface of this sphere. The process was repeated to derive the average arrival time. In addition, the diffusion coefficient of chloride ions was deduced. The effectiveness of the method was also tentatively confirmed by the experimental data.