An experimental and numerical study of alkali-activated fly ash paste – from dissolution kinetics to microstructure formation

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research Pub Date : 2025-07-22 DOI:10.1016/j.cemconres.2025.107999

Yun Chen , Jiayi Chen , Mayank Gupta , Xuhui Liang , Luiz Miranda de Lima , Zhiyuan Xu , Yibing Zuo , Suhong Yin , Qijun Yu , Guang Ye

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引用次数: 0

Abstract

This study presents an extended numerical approach based on GeoMicro3D to simulate the reaction kinetics and three-dimensional (3D) microstructure evolution of alkali-activated fly ash (AAFA). Dissolution experiments were conducted under varying NaOH concentrations and temperatures to formulate predictive rate functions for Si and Al release. These experimentally derived kinetic functions, alongside a thermodynamic dataset for N-(C-)A-S-H gels, were incorporated into the GeoMicro3D model to capture the chemical reactions and 3D microstructure evolution of AAFA. The model well captured reaction degree of fly ash, formation of solid products, evolution of pore solution compositions, and porosity over time. Notably, it is the first to predict the time-dependent spatial distribution of phases within the 3D AAFA microstructure by integrating kinetic and microstructural modeling. Dual validation using both dissolution data and microstructural metrics demonstrates the model's reliability and robustness. This integrated framework provides new insights into the coupled chemical–microstructural evolution of alkali-activated materials.

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碱活化粉煤灰膏体的实验与数值研究——从溶解动力学到微观结构形成

本文提出了一种基于GeoMicro3D的扩展数值方法来模拟碱活化粉煤灰（AAFA）的反应动力学和三维（3D）微观结构演化。在不同的NaOH浓度和温度下进行了溶解实验，以建立Si和Al释放的预测速率函数。这些实验导出的动力学函数，以及N-(C-) a - s - h凝胶的热力学数据集，被整合到GeoMicro3D模型中，以捕捉AAFA的化学反应和3D微观结构演变。该模型较好地捕捉了粉煤灰的反应程度、固体产物的形成、孔隙溶液组成的演变以及孔隙度随时间的变化。值得注意的是，这是第一个通过整合动力学和微观结构建模来预测三维AAFA微观结构中相的时空分布的研究。使用溶解数据和微观结构指标的双重验证证明了模型的可靠性和稳健性。这一综合框架为碱活化材料的化学-微观结构耦合演化提供了新的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Cement and Concrete Research 工程技术-材料科学：综合

CiteScore

20.90

自引率

12.30%

发文量

318

审稿时长

53 days

期刊介绍： Cement and Concrete Research is dedicated to publishing top-notch research on the materials science and engineering of cement, cement composites, mortars, concrete, and related materials incorporating cement or other mineral binders. The journal prioritizes reporting significant findings in research on the properties and performance of cementitious materials. It also covers novel experimental techniques, the latest analytical and modeling methods, examination and diagnosis of actual cement and concrete structures, and the exploration of potential improvements in materials.