Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent
Tricalcium silicate (C<sub>3</sub>S) as a binder material has a decisive influence on the processes of hardening and strength gain of cements and concretes. One of the promising directions is the introduction of dispersed additives into cement mixtures, which allow micro-level control of...
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MDPI AG
2023-11-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/22/7078 |
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| author | Yurii R. Krivoborodov Svetlana V. Samchenko Andrey V. Korshunov Irina V. Kozlova Dmitrii G. Alpacky |
| author_facet | Yurii R. Krivoborodov Svetlana V. Samchenko Andrey V. Korshunov Irina V. Kozlova Dmitrii G. Alpacky |
| author_sort | Yurii R. Krivoborodov |
| collection | DOAJ |
| description | Tricalcium silicate (C<sub>3</sub>S) as a binder material has a decisive influence on the processes of hardening and strength gain of cements and concretes. One of the promising directions is the introduction of dispersed additives into cement mixtures, which allow micro-level control of the composition of hydration products and change the dynamics of the structure formation of cement stone. In this paper, the effect of a microdisperse ettringite additive on the kinetics of the hydration and hardening process of tricalcium silicate was studied. It was shown that ettringite crystals selectively adsorb Ca<sup>2+</sup> and OH<sup>−</sup> ions from a saturated solution of calcium hydroxide, which contributes to the formation of hydrosilicate nuclei on their surface during cement hydration. Hydration of C<sub>3</sub>S in the presence of ettringite proceeds more intensively; the addition of ettringite contributes to an increase in the content of calcium hydrosilicates in hydration products at the initial stage of the process. Addition of 10 wt.% ettringite to C<sub>3</sub>S reduces the induction period of the beginning of the main phase of heat release by around two times and increases the amount of heat released on the 1st day of hydration by 15% compared to the control sample. According to electron microscopy data, it was found that during the first hours of hydration of modified C<sub>3</sub>S, a significant number of nuclei of fibrous particles of calcium hydrosilicates with sizes of 0.2–2 microns were formed on the surface of ettringite crystals. According to the results of kinetic modeling of the setting process of cement pastes using the Avrami–Erofeyev model, it was shown that in the presence of the addition of microcrystals of ettringite, the setting rate is characterized by a slowdown in nucleation, whereas for a sample without an additive, this process proceeds with an acceleration of the formation of solid-phase nuclei. Based on the comparison of kinetic results and mechanical measurements, it is concluded that needle crystals of ettringite during C<sub>3</sub>S hydration and cement stone hardening are preformed centers for the growth of hydrosilicate nuclei, and they also act as a reinforcing filler, increasing the bending strength of modified samples. The results of the work can be used in practice in the development of methods for controlling the processes of hydration and hardening of cements, as well as for controllable structure formation of cement stone which is important in particular for 3D printing of building products and constructions. |
| first_indexed | 2024-03-09T16:39:14Z |
| format | Article |
| id | doaj.art-8a826cd42709494ab02d74fbddcac0a4 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T16:39:14Z |
| publishDate | 2023-11-01 |
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| spelling | doaj.art-8a826cd42709494ab02d74fbddcac0a42023-11-24T14:53:20ZengMDPI AGMaterials1996-19442023-11-011622707810.3390/ma16227078Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating AgentYurii R. Krivoborodov0Svetlana V. Samchenko1Andrey V. Korshunov2Irina V. Kozlova3Dmitrii G. Alpacky4Department of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, RussiaDepartment of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, RussiaDepartment of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, RussiaDepartment of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, RussiaDepartment of Building Materials, Moscow State University of Civil Engineering, 26, Yaroslavskoye Shosse, 129337 Moscow, RussiaTricalcium silicate (C<sub>3</sub>S) as a binder material has a decisive influence on the processes of hardening and strength gain of cements and concretes. One of the promising directions is the introduction of dispersed additives into cement mixtures, which allow micro-level control of the composition of hydration products and change the dynamics of the structure formation of cement stone. In this paper, the effect of a microdisperse ettringite additive on the kinetics of the hydration and hardening process of tricalcium silicate was studied. It was shown that ettringite crystals selectively adsorb Ca<sup>2+</sup> and OH<sup>−</sup> ions from a saturated solution of calcium hydroxide, which contributes to the formation of hydrosilicate nuclei on their surface during cement hydration. Hydration of C<sub>3</sub>S in the presence of ettringite proceeds more intensively; the addition of ettringite contributes to an increase in the content of calcium hydrosilicates in hydration products at the initial stage of the process. Addition of 10 wt.% ettringite to C<sub>3</sub>S reduces the induction period of the beginning of the main phase of heat release by around two times and increases the amount of heat released on the 1st day of hydration by 15% compared to the control sample. According to electron microscopy data, it was found that during the first hours of hydration of modified C<sub>3</sub>S, a significant number of nuclei of fibrous particles of calcium hydrosilicates with sizes of 0.2–2 microns were formed on the surface of ettringite crystals. According to the results of kinetic modeling of the setting process of cement pastes using the Avrami–Erofeyev model, it was shown that in the presence of the addition of microcrystals of ettringite, the setting rate is characterized by a slowdown in nucleation, whereas for a sample without an additive, this process proceeds with an acceleration of the formation of solid-phase nuclei. Based on the comparison of kinetic results and mechanical measurements, it is concluded that needle crystals of ettringite during C<sub>3</sub>S hydration and cement stone hardening are preformed centers for the growth of hydrosilicate nuclei, and they also act as a reinforcing filler, increasing the bending strength of modified samples. The results of the work can be used in practice in the development of methods for controlling the processes of hydration and hardening of cements, as well as for controllable structure formation of cement stone which is important in particular for 3D printing of building products and constructions.https://www.mdpi.com/1996-1944/16/22/7078tricalcium silicatehydrationmicrodispersed ettringitenucleation siteskinetics of settingbending strength |
| spellingShingle | Yurii R. Krivoborodov Svetlana V. Samchenko Andrey V. Korshunov Irina V. Kozlova Dmitrii G. Alpacky Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent Materials tricalcium silicate hydration microdispersed ettringite nucleation sites kinetics of setting bending strength |
| title | Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent |
| title_full | Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent |
| title_fullStr | Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent |
| title_full_unstemmed | Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent |
| title_short | Increasing the Hydration Activity of Tricalcium Silicate by Adding Microdispersed Ettringite as a Nucleating Agent |
| title_sort | increasing the hydration activity of tricalcium silicate by adding microdispersed ettringite as a nucleating agent |
| topic | tricalcium silicate hydration microdispersed ettringite nucleation sites kinetics of setting bending strength |
| url | https://www.mdpi.com/1996-1944/16/22/7078 |
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