Climate Change Data Portal
DOI | 10.1016/j.conbuildmat.2024.135985 |
Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N-A-S-H) geopolymers' hydric properties | |
Degefu, Dagmawi Mulugeta; Berardi, Umberto | |
发表日期 | 2024 |
ISSN | 0950-0618 |
EISSN | 1879-0526 |
起始页码 | 425 |
卷号 | 425 |
英文摘要 | Anthropogenic climate change is one of the main reasons for mainstreaming sustainability in all sectors. Reducing the carbon footprint of the built environment is one of the sustainability goals which is universally accepted. Reducing the carbon emissions from buildings entails cutting back operational and embodied carbon. Geopolymers are one of these materials that have been under focus recently for their capacity to reduce these two sources' emissions in buildings. In this study, the authors added to their previous work on understanding aerated geopolymers' performance as building materials. This article presents the effect of Na/Al ratio and curing moisture on the moisture storage, transfer, and moisture buffering capacity (MBC) of aerated geopolymers. The impact of vapor gradient and exposure to variable environmental conditions (temperature and relative humidity (%RH)) are also surveyed. Generally, the results show correlations between hydric performance and the tested experimental parameters. This stems from the influence of Na/Al and curing relative humidity on the degree of geopolymerization, rate of reaction, porosity, and phase composition of metakaolin-based geopolymers. Vapor permeability and moisture diffusivity increased with rising alkali oxide content because of the higher degree decomposition of porogen and pore stabilization effect of rapid polycondensation. Moisture permeability and diffusivity also showed direct relationships with curing relative humidity. Low relative humidity results in the rapid loss of inter -layer water and leads to densification of the matrix, while high %RH curing is suitable for pore formation and stability. The MBC of the samples increases with increasing Na/Al because of increased porosity leading to access to more gel pores. However, at high values, the sub -carbonation (internal carbonation) and carbonation lead to the formation of sodium carbonate, which is highly hydrophilic and influences the material's moisture exchange capacity negatively. This justifies the lower MBC at Na/Al =1. A similar observation was made when curing moisture content was increased. The influence of the Na/Al and curing moisture on the pore statistics of the geopolymer matrix are observed by their adsorption isotherms. At lower curing humidity and Na/Al, the samples tend to be less macroporous, dominated mainly by micropores. This is evidenced by the onset of capillary condensation at low %RH because of raid pore filling. The results also demonstrate the critical role Na/ Al plays in determining the resulting matrix's microstructural integrity. This is evidenced by the low durability of the sample with Na/Al equal to 1.2. The samples' loss of structural integrity is because of carbonation -triggered retardation of strength development and stress put on micropores because of sub -carbonation -driven crystallization. |
英文关键词 | Sustainable building materials; Geopolymers; Sodium Aluminosilicate Hydrate; Hydric capacity; Moisture permeability; Moisture buffer capacity; Carbonation |
语种 | 英语 |
WOS研究方向 | Construction & Building Technology ; Engineering ; Materials Science |
WOS类目 | Construction & Building Technology ; Engineering, Civil ; Materials Science, Multidisciplinary |
WOS记录号 | WOS:001226871800001 |
来源期刊 | CONSTRUCTION AND BUILDING MATERIALS
![]() |
文献类型 | 期刊论文 |
条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/306537 |
作者单位 | University of Toronto; Toronto Metropolitan University |
推荐引用方式 GB/T 7714 | Degefu, Dagmawi Mulugeta,Berardi, Umberto. Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N-A-S-H) geopolymers' hydric properties[J],2024,425. |
APA | Degefu, Dagmawi Mulugeta,&Berardi, Umberto.(2024).Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N-A-S-H) geopolymers' hydric properties.CONSTRUCTION AND BUILDING MATERIALS,425. |
MLA | Degefu, Dagmawi Mulugeta,et al."Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N-A-S-H) geopolymers' hydric properties".CONSTRUCTION AND BUILDING MATERIALS 425(2024). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。