基于多离子传输的混凝土细微观尺度多相数值模拟

Multi-Phase Modelling of Concrete at Meso-micro Scale Based on Multi-species Transport

基于严格的Gaussian静电理论和对多相结构的参数控制,考虑多种离子间电化学耦合效应和骨料、界面过渡区的不同形状及体积分数,在细微观尺度下建立多离子传输多相数值模型。通过求解质量守恒方程和Poisson方程,探明多离子的时空分布规律。综合考虑外加电场、离子间相互作用、混凝土的各向异性、骨料-砂浆界面过渡区和离子吸附结合效应等因素的影响,揭示了多离子传输与单一离子传输间的差异,以及多种曲折度效应之间的增益效果和影响程度。

A series of ‘double-multi’ models were developed in a meso-micro scale, in which the electro-coupling phenomenon of multi-species as well as various shapes and volume fractions of aggregates and ITZs was considered, based on the institutive electrochemistry law and parameter control of multi phases numerical modeling method. The spatial-temporal distribution characteristics of multi-component ionic transport were obtained by solving both the mass conservation equation and the Poisson equation. Through a comparatively overall study by considering a set of important influencing factors including external electric field, interactions between different species, heterogeneous nature of concrete, ITZ and binding effect, etc., some important transport features such as multi-species transport behavior and various tortuosity effects were revealed.