| Autor: |
Jie Hou, Xiuzhi Zhang, Chong Zhang, Jing Wang, Peiqi Zheng, Jingli Huang, Shuxia Feng, Jinbang Wang, Guangbin Duan |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
Case Studies in Construction Materials, Vol 21, Iss , Pp e03995- (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2214-5095 |
| DOI: |
10.1016/j.cscm.2024.e03995 |
| Popis: |
The early microstructural evolution process of alkali-activated materials (AAMs) paste plays a crucial role in determining its workability and mechanical properties, which are reflected in the paste’s rheological behavior. However, the rapid development of early rheological properties of AAMs seriously affected its application. The paper investigates the early time-dependent rheology of alkali-activated slag (AAS) by sodium silicate. The relationship between the distribution space of free water and the rheological properties of AAS is established, which is of great significance for adjusting the rheological properties of AAMs. The reaction process and macroscopic structural evolution of AAS were observed through hydration heat tests and rheological performance tests, respectively. Additionally, the ion content and free water in the AAS solution were measured using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and low-field nuclear magnetic resonance (LF NMR) techniques. The findings indicate that the early structural development of AAS comprises two stages: the “suspension stage” and the “rapid hardening stage.” During the suspension stage (less than 15 min), an initial dissolution heat release peak appears in the hydration heat curve. At this stage, the gel products are in the preliminary stage of aggregation reaction, characterized by a loose structure and low free water content (less than 1 %) in the gel pores. However, during the rapid hardening stage (more than 15 min), the aggregation reaction gradually promotes the growth and interconnection of gels. The free water content in the gel pores increases rapidly, leading to the encapsulation of slag particles by the gels, thus forming a rigid structure. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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