Sulfuric acid resistance behaviour of alkali-activated slag and waste glass powder blended precursors

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

Cement & concrete composites Pub Date : 2023-10-16 DOI:10.1016/j.cemconcomp.2023.105319

Keke Sun, Hafiz Asad Ali, Dongxing Xuan, Chi Sun Poon

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引用次数: 0

Abstract

The acid resistance of cementitious materials is an important property when exposed to aggressive acidic environments. In this study, the waste glass powder (GP) and slag as precursors were activated by alkali (Na or K)-silicates or by a combination of (Na or K)-silicates with air pollution control (APC) residues to produce alkali-activated materials (AAMs) and alkali/sulfate-activated materials (ASAMs). The compressive strength and volume change of the AAMs and ASAMs mortar were performed to understand the influence of sulfuric acid attack on the resulting performances. Meanwhile, the microstructure and micro-mechanics evolution were investigated by the nanoindentation technology. The results showed that the compressive strengths of all AAMs and ASAMs mortar decreased under a low pH solution. The Na- and K-AAMs mortar exposed to the acid solution shrank considerably even though a large amount of gypsum formed, while the Na- and K-ASAMs exhibited certain expansion behavior due to the existing sodium sulfate. Upon the sulfuric acid attack, the framework changes of the K-A-S-H/N-A-S-K caused by dealumination had less effect on the integrity than the dealumination and decalcification of the C(-A)-S-H gel. In comparing the alkali cations, the K-type activator impacted more positively than the Na-type activator for the performance development of the AAMs and ASAMs under the sulfuric acid attack. Moreover, the AAMs and ASAMs showed a buffering capacity of acid. This work provides a scientific reference value for applying the AAMs and ASAMs in real environments.

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碱矿渣和废玻璃粉混合前驱体的抗硫酸性能

当暴露在侵蚀性酸性环境中时，胶凝材料的耐酸性是一个重要的特性。在本研究中，废玻璃粉（GP）和矿渣作为前体，通过碱（Na或K）-硅酸盐或（Na或K）-硅酸盐与空气污染控制（APC）残留物的组合进行活化，生产碱活性材料（AAM）和碱/硫酸盐活性材料（ASAM）。对AAM和ASAMs砂浆的抗压强度和体积变化进行了研究，以了解硫酸侵蚀对其性能的影响。同时，利用纳米压痕技术对其微观结构和微观力学演化进行了研究。结果表明，在低pH溶液中，所有AAM和ASAM砂浆的抗压强度都有所下降。即使形成了大量石膏，暴露于酸溶液中的Na和K-AAM砂浆也会显著收缩，而由于存在硫酸钠，Na和K-ASAM表现出一定的膨胀行为。在硫酸侵蚀下，脱铝引起的K-A-S-H/N-A-S-K的骨架变化对完整性的影响小于C（-A）-S-H凝胶的脱铝和脱钙。在比较碱阳离子时，K型活化剂对AAM和ASAM在硫酸侵蚀下的性能发展的影响比Na型活化剂更积极。此外，AAM和ASAM显示出对酸的缓冲能力。这项工作为AAM和ASAM在实际环境中的应用提供了科学的参考价值。

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.