Characterization and analysis of the self-healing behavior of alkali-activated slag mortar

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites Pub Date : 2025-04-20 DOI:10.1016/j.cemconcomp.2025.106097

Yanshuai Wang , Hao Ye , Rongxin Peng , Xiangping Xian , Shuxian Hong

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引用次数: 0

Abstract

Alkali-activated slag (AAS) mortar has substantial limitations owing to its autogenous shrinkage, which leads to crack formation, and the self-healing property presents a promising solution to maintain its integrity and durability. Based on this, the self-healing efficiency of AAS mortar under a stable alkaline environment was assessed, with exogenous calcium ions introduced via a Ca(OH)₂ solution, and the self-healing mechanism was investigated with exogenous carbonate ions introduced to promote carbonation. To evaluate the effectiveness of these methods, both the physical properties and the microstructural characteristics of the AAS mortar under different healing environments were analyzed. The results revealed that self-healing environments, including secondary alkali activation and carbonation, substantially improved the rates of compressive strength recovery to 97.96 % and permeability recovery to 32.1 %. AAS mortar samples immersed in a saturated Ca(OH)₂ solution with wet-dry cycles, as well as those alternatingly immersed in Ca(OH)₂ and Na₂CO₃ showed higher matrix-crack bond strength recovery rates (43.7 % and 23.1 %, respectively) than samples exposed to only a saturated Ca(OH)₂ solution (11.4 %). The predominant healing products, including CaCO₃ and calcium aluminum silicate hydrate, effectively bonded to the cracks, contributing to significant recovery of the physical properties. Thus, the optimal self-healing of the AAS mortar requires an alkaline environment with abundant calcium ions to improve CaCO₃ precipitation. Additionally, continuous carbonation with exogenous carbonate ions further improves the healing efficiency.

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碱活化矿渣砂浆自愈性能的表征与分析

碱活性渣（AAS）砂浆的自收缩会导致裂缝的形成，因而具有很大的局限性，而碱活性渣（AAS）砂浆的自修复性能是保持其完整性和耐久性的一种很有希望的解决方案。在此基础上，通过Ca(OH)2溶液引入外源钙离子，评估了稳定碱性环境下AAS砂浆的自修复效率，并探讨了外源碳酸盐离子促进碳酸化的自修复机理。为了评估这些方法的有效性，分析了不同愈合环境下AAS砂浆的物理性能和微观结构特征。结果表明，包括二次碱活化和碳酸化在内的自修复环境显著提高了抗压强度恢复率，达到97.96%，渗透率恢复率达到32.1%。浸没在饱和Ca(OH)2溶液中，以及在Ca(OH)2和Na2CO3中交替浸没的AAS砂浆样品，其基体-裂缝粘结强度恢复率分别为43.7%和23.1%，高于仅浸没在饱和Ca(OH)2溶液中的11.4%。主要的修复产物，包括CaCO3和水合硅酸铝钙，有效地结合在裂缝上，有助于显著恢复物理性能。因此，AAS砂浆的最佳自愈需要具有丰富钙离子的碱性环境来改善CaCO3的沉淀。此外，外源碳酸盐离子的持续碳化进一步提高了愈合效率。

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 & concrete composites 工程技术-材料科学：复合

CiteScore

18.70

自引率

11.40%

发文量

459

审稿时长

65 days

期刊介绍： Cement & concrete composites focuses on advancements in cement-concrete composite technology and the production, use, and performance of cement-based construction materials. It covers a wide range of materials, including fiber-reinforced composites, polymer composites, ferrocement, and those incorporating special aggregates or waste materials. Major themes include microstructure, material properties, testing, durability, mechanics, modeling, design, fabrication, and practical applications. The journal welcomes papers on structural behavior, field studies, repair and maintenance, serviceability, and sustainability. It aims to enhance understanding, provide a platform for unconventional materials, promote low-cost energy-saving materials, and bridge the gap between materials science, engineering, and construction. Special issues on emerging topics are also published to encourage collaboration between materials scientists, engineers, designers, and fabricators.