Experimental Study on MgO-Na2CO3 Combined Excitation Recycled Fine-Powder-Slag Cementitious System and Modification
Author(s): |
Jianping Liu
Yulin Tian Xiaowei Ge Bing Liu Kaixin Liu Ge Song |
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Medium: | journal article |
Language(s): | English |
Published in: | Buildings, 21 February 2024, n. 3, v. 14 |
Page(s): | 592 |
DOI: | 10.3390/buildings14030592 |
Abstract: |
The hydration mechanism and strength development of alkaline salt-activated cementitious materials primarily rely on the alkaline activators and mineral admixtures employed. However, the impact of increased Mg2+, Al3+, and Si4+ resulting from the addition of MgO and steel slag (SS) on the hydration mechanism of these systems remains undetermined. This study delves into the hydration mechanism and mechanical properties of a Na2CO3-MgO-activated regenerated micropowder-slag-based cementitious material system. Mechanical properties were assessed by measuring dry shrinkage and compressive strength at various ages, up to 28 days. The reaction mechanism was scrutinized using X-ray diffraction and a thermogravimetric analysis. The main reaction products contributing to the strength development are C-S-H, C-(A)-S-H gel, and hydrotalcite. Other carbonate-containing phases make smaller contributions. The findings reveal that when SS usage is at 10%, it yields higher early strength compared to ordinary samples. Samples incorporating MgO and SS achieved strengths similar to or surpassing those of the control samples. A noteworthy observation is the synergistic excitation effect between sodium carbonate (NC) and MgO, leading to the generation of a significant amount of gelling substances. These substances fill the pores of the structure, resulting in the formation of a dense microstructure. Consequently, the enhanced interaction between NC and MgO contributes to the overall strength development of the cementitious material. |
Copyright: | © 2024 by the authors; licensee MDPI, Basel, Switzerland. |
License: | This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met. |
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data sheet - Reference-ID
10773493 - Published on:
29/04/2024 - Last updated on:
05/06/2024