Effect of Fly Ash Properties on Strength Development of Microwave-Heated Alkali-Activated Binder

被引：0
|
作者：
Zhu H. [1 ,2 ,3 ]
Yu C. [1 ]
Zhang X. [1 ]
Qiao P. [1 ]
Li H. [1 ,2 ,3 ]
机构：
[1] College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an
[2] Ecological Cement Engineering Research Center of Ministry of Education, Xi'an University of Architecture and Technology, Xi'an
[3] Shaanxi Ecological Cement & Concrete Engineering Technology Research Center, Xi'an University of Architecture and Technology, Xi'an
来源：
Jianzhu Cailiao Xuebao/Journal of Building Materials | 2023年 / 26卷 / 05期
关键词：
alkali⁃activated binder; fly ash property; microwave⁃heated; strength development;
D O I：
10.3969/j.issn.1007-9629.2023.05.001
中图分类号：
学科分类号：
摘要：
Alkali⁃activated fly ash(AAFA)binders were prepared from fly ash with different calcium content and fineness,and were cured by microwave heating at the early stage of hydration. The developments of compressive strength and microstructure of AAFA specimens were studied and the influence mechanism of microwave heating on strength development was discussed. The results show that increasing the calcium content in fly ash and appropriately reducing the fineness of fly ash can significantly improve the compressive strength of AAFA specimens after microwave heating,but aggravate the strength loss after 28 d. The reason for the strength loss of AAFA specimens cured by microwave heating lies in the dissolution and carbonation of calcium ions in aluminum⁃modified calcium silicate hydrate(C(⁃ A)⁃S⁃H)gel,resulting in the formation of sponge like gel with low density and the decomposition and volume reduction of sodium aluminosilicate hydrate(N⁃A⁃S⁃H)gel. The compressive strength of AAFA specimens prepared from ultrafine fly ash(D50=3.96 μm)is much lower than that of the reference specimen,therefore the former is not suitable for microwave⁃heated curing. © 2023 Tongji University. All rights reserved.
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页码：449 / 456
页数：7
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