Reactive transport modelling of autogenous self-healing in cracked concrete

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

Cement and Concrete Research Pub Date : 2024-11-21 DOI:10.1016/j.cemconres.2024.107733

Daniel Lahmann, Sylvia Keßler

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引用次数: 0

Abstract

Autogenous self-healing can close cracks in water-retaining concrete structures. However, its inconsistent efficiency in building practice indicates that the underlying processes are not fully understood. Therefore, this study characterizes reactive transport through cracked concrete and models it using PHREEQC to develop a comprehensive understanding of chemical processes promoting autogenous self-healing. Driven by the dissolution of portlandite, the main cause of healing is the precipitation of CaCO3, which contributes to a crack closure of up to 113 μm. This process is supported by the formation of M-S-H and C-S-H. As self-healing progresses, the rates of dissolution and precipitation processes that promote healing decrease exponentially. At initial flow rates >2 L h−1, CaCO3 precipitation is favored towards the crack outlet. At lower initial flow rates, the formation of CaCO3 shifts towards the crack inlet. These findings underscore the need to reconsider the reliance on effective healing in practical applications.

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裂缝混凝土自生自愈的反应传输模型

自生自愈可以封闭保水混凝土结构中的裂缝。然而，其在建筑实践中的效率并不一致，这表明人们对其基本过程并不完全了解。因此，本研究描述了裂缝混凝土中反应性迁移的特征，并使用 PHREEQC 建立模型，以全面了解促进自生自愈合的化学过程。受波长石溶解的驱动，愈合的主要原因是 CaCO3 的析出，这有助于裂缝闭合达 113 μm。M-S-H 和 C-S-H 的形成为这一过程提供了支持。随着自愈合的进行，促进愈合的溶解和沉淀过程的速率呈指数下降。在初始流速为 >2 L h-1 时，CaCO3 向裂缝出口沉淀。在较低的初始流速下，CaCO3 的形成转向裂缝入口。这些发现突出表明，在实际应用中需要重新考虑对有效愈合的依赖。

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.