Micro/meso scales characterization of alkali-activated fly ash-slag concrete under sustained high-temperatures with X-CT, MIP, and SEM tests

IF 7.1 3区材料科学 Q1 GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY

Materials Today Sustainability Pub Date : 2024-11-01 DOI:10.1016/j.mtsust.2024.101036

Hongqiang Ma , Congcong Fu , Jialong Wu , Xinhua Yuan , Chao Wu , Jingjing Feng

{"title":"Micro/meso scales characterization of alkali-activated fly ash-slag concrete under sustained high-temperatures with X-CT, MIP, and SEM tests","authors":"Hongqiang Ma , Congcong Fu , Jialong Wu , Xinhua Yuan , Chao Wu , Jingjing Feng","doi":"10.1016/j.mtsust.2024.101036","DOIUrl":null,"url":null,"abstract":"<div><div>Based on X-CT, MIP, and SEM tests, the micro/meso scales evolutions of alkali-activated fly ash-slag (AAFS) concrete under sustained high temperatures are studied. The results show that the water loss of the C–S–H and C-A-S-H gel phases at 60 °C is continuous (about 60d). The variation law of meso-scale pore volume based on the X-CT test is consistent with that of micro-scale pore volume obtained by the MIP test. The 2D fractal dimension can be used to qualitatively evaluate the internal micro-cracks and microstructure complexity of AAFS concrete after sustained high-temperature action. The mass loss rate can reach stability within 3d-7d under the action of 100 °C, 150 °C, and 200 °C, and there is no cumulative effect of micro-cracks and pores caused by initial water loss. Under sustained high-temperatures, the internal pore structure, micro-cracks, and microstructure changes of AAFS concrete are persistent, and these persistent changes lead to a significant change in the mechanical properties of AAFS concrete.</div></div>","PeriodicalId":18322,"journal":{"name":"Materials Today Sustainability","volume":"28 ","pages":"Article 101036"},"PeriodicalIF":7.1000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Today Sustainability","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2589234724003725","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Based on X-CT, MIP, and SEM tests, the micro/meso scales evolutions of alkali-activated fly ash-slag (AAFS) concrete under sustained high temperatures are studied. The results show that the water loss of the C–S–H and C-A-S-H gel phases at 60 °C is continuous (about 60d). The variation law of meso-scale pore volume based on the X-CT test is consistent with that of micro-scale pore volume obtained by the MIP test. The 2D fractal dimension can be used to qualitatively evaluate the internal micro-cracks and microstructure complexity of AAFS concrete after sustained high-temperature action. The mass loss rate can reach stability within 3d-7d under the action of 100 °C, 150 °C, and 200 °C, and there is no cumulative effect of micro-cracks and pores caused by initial water loss. Under sustained high-temperatures, the internal pore structure, micro-cracks, and microstructure changes of AAFS concrete are persistent, and these persistent changes lead to a significant change in the mechanical properties of AAFS concrete.

查看原文本刊更多论文

通过 X-CT、MIP 和 SEM 试验表征持续高温条件下碱激活粉煤灰-矿渣混凝土的微观/宏观尺度特性

基于 X-CT、MIP 和 SEM 测试，研究了碱激活粉煤灰-矿渣（AAFS）混凝土在持续高温下的微观/宏观尺度演变。结果表明，在 60 °C 时，C-S-H 和 C-A-S-H 凝胶相的失水是持续的（约 60d）。根据 X-CT 试验得出的中尺度孔隙体积变化规律与 MIP 试验得出的微尺度孔隙体积变化规律一致。二维分形维数可用于定性评估 AAFS 混凝土在持续高温作用后的内部微裂缝和微结构复杂性。在 100 ℃、150 ℃ 和 200 ℃ 的作用下，质量损失率可在 3d-7d 内达到稳定，且不存在由初始失水引起的微裂缝和孔隙累积效应。在持续高温作用下，AAFS 混凝土的内部孔隙结构、微裂缝和微观结构变化具有持久性，这些持久性变化导致 AAFS 混凝土的力学性能发生显著变化。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Materials Today Sustainability Multiple-

CiteScore

5.80

自引率

6.40%

发文量

174

审稿时长

32 days

期刊介绍： Materials Today Sustainability is a multi-disciplinary journal covering all aspects of sustainability through materials science. With a rapidly increasing population with growing demands, materials science has emerged as a critical discipline toward protecting of the environment and ensuring the long term survival of future generations.