Self-Waterproofing Performance of Repair Mortars With Inorganic Healing Agents

MATEC Web of Conferences Pub Date : 2023-01-01 DOI:10.1051/matecconf/202337803001

Padmapriya Arul Kumar, S. Rengaraju, A. Al-Tabbaa

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Abstract

In Europe, about 55% of concrete bridges are about 50 years old and require non-structural rapid repair strategies to reinstate the aesthetic and durability performances. Existing strategies focus primarily on superficial restoration that continues to demonstrate premature deterioration due to inevitable micro-crack formations that further propagate to macro-cracks leading to the ingress of moisture along with harmful ions. In this study, the benefits of self-healing technology to control moisture ingress at the microscale were investigated. For this, tailored microcapsule with inorganic healing agent, specifically, commercially available water-repellent agent (SIKAGARD 705L) was added to mortar with two types of commonly used binders namely CEMI 52.5N and CEMI 52.5R. The compatibility assessment in terms of capsule integration, fresh and hardened properties was done. The baseline healing efficiency of the mortars without any healing additions was obtained to understand the autogenous healing capacity of the reference mortars. Subsequently, the reference mortar mixes were compared with mixes containing varying fractions of microcapsules (3, 5, and 10%) for autonomous healing efficiency with capillary absorption as the main durability function. The healing efficiency was further investigated for two different crack mouth widths (<250 μm and >350 μm); representative of non-structural residual crack widths. In mortars with microcapsules, a maximum reduction of sorptivity coefficients up to 82% and 78% with CEMI 52.5N and CEMI 52.5R mortars, respectively, for specimens cracked after 7 days of curing was observed. Subsequently, a synergetic effect of autogenous healing action and autonomous water-repellent action for durability recovery was identified and proved useful for repair mortar applications. The healing agent investigated, capsule content, and healing environment considered in the current study lay a foundation for further optimisation to improve the performance and to suit different applications.

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无机愈合剂修补砂浆的自防水性能

在欧洲，大约55%的混凝土桥梁已有50年左右的历史，需要非结构性的快速修复策略来恢复美学和耐用性。现有的策略主要集中在表面修复，由于不可避免的微裂缝形成，进一步扩展到宏观裂缝，导致水分和有害离子的进入，导致过早退化。在这项研究中，研究了自愈技术在微观尺度上控制水分侵入的好处。为此，将定制微胶囊与无机愈合剂，特别是市售的防水剂(SIKAGARD 705L)添加到砂浆中，并使用两种常用的粘合剂(CEMI 52.5N和CEMI 52.5R)。从胶囊整合性、新鲜性和硬化性等方面进行相容性评价。为了了解参考迫击炮的自愈能力，我们得到了未添加任何自愈剂的迫击炮的基线自愈效率。随后，将参考砂浆混合物与含有不同比例微胶囊(3、5和10%)的混合物进行比较，以毛细管吸收为主要耐久性功能的自主愈合效率。进一步研究了两种不同裂纹口宽度(350 μm)下的愈合效率;非结构残余裂缝宽度的代表。在微胶囊砂浆中，CEMI 52.5N和CEMI 52.5R砂浆在养护7 d后，试样的吸附系数最大分别降低了82%和78%。随后，自愈合作用和自主拒水作用对耐久性恢复的协同作用被确定，并被证明对修复砂浆的应用是有用的。本研究中所研究的愈合剂、胶囊含量和愈合环境为进一步优化奠定了基础，以提高性能并适应不同的应用。

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

MATEC Web of Conferences

自引率

0.00%

发文量

342

审稿时长

6 weeks

期刊介绍： MATEC Web of Conferences is an Open Access publication series dedicated to archiving conference proceedings dealing with all fundamental and applied research aspects related to Materials science, Engineering and Chemistry. All engineering disciplines are covered by the aims and scope of the journal: civil, naval, mechanical, chemical, and electrical engineering as well as nanotechnology and metrology. The journal concerns also all materials in regard to their physical-chemical characterization, implementation, resistance in their environment… Other subdisciples of chemistry, such as analytical chemistry, petrochemistry, organic chemistry…, and even pharmacology, are also welcome. MATEC Web of Conferences offers a wide range of services from the organization of the submission of conference proceedings to the worldwide dissemination of the conference papers. It provides an efficient archiving solution, ensuring maximum exposure and wide indexing of scientific conference proceedings. Proceedings are published under the scientific responsibility of the conference editors.